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Background: A healthy eating pattern such as the Mediterranean-style healthy eating pattern (MED-HEP) is associated with favorable effects on both cardiometabolic risk markers and self-reported health outcomes. Limited evidence exists regarding the influence of the glycemic index (GI) of carbohydrate foods consumed within a healthy eating pattern on self-reported health status and sleep., Objectives: To investigate the effects of a low- compared with high-GI MED-HEP on changes in health-related quality of life (HRQoL) and sleep., Methods: The MEDGICarb-intervention trial is a 12-wk randomized, controlled, parallel multi-center trial in adults with ≥2 features of the metabolic syndrome. Participants consumed an eu-energetic diet profiled as a MED-HEP with either low GI (experimental) or high GI (control). HRQoL and sleep were measured with Medical Outcomes Study 36-item short-form health survey version 2, Pittsburgh sleep quality index, and Epworth Sleepiness Scale at baseline and postintervention., Results: One hundred and sixty adults with ≥2 features of the metabolic syndrome completed the intervention [53% females, age 56 ± 10 y, body mass index (kg/m 2 ) 31.0 ± 3.1]. Low- compared with high-GI MED-HEP resulted in differential changes between the groups in the HRQoL domains role physical [5.6 ± 2.2 arbitrary units (AU) compared with -2.5 ± 2.5 AU) and vitality (6.9 ± 1.7 AU compared with 0.0 ± 1.8 AU] (P < 0.05), which were driven mostly by improvements in the low-GI group. There were no significant differences between the MED-HEPs for changes in aggregated physical or mental components or for the other individual domains of HRQoL (physical functioning, bodily pain, general health, social functioning, role emotional, and mental health) or for sleep quality or daytime sleepiness., Conclusions: Low compared to high GI in the context of a MED-HEP resulted in modest improvements in some, but not all, health domains of HRQoL. No major differences were seen between the groups for measures of sleep. This trial was registered at clinicaltrials.gov as NCT03410719., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Although experimental research supports that resistance training (RT), especially with greater dietary protein intake, improves muscle mass and strength in older adults, comparable research on tendons is needed., Objectives: We assessed the effects of a protein-rich diet emphasizing lean beef, compared with 2 control diets, on RT-induced changes in skeletal muscle and tendon size and strength in older women., Methods: We randomly assigned women [age: 66 ± 1 y, body mass index (BMI): 28 ± 1] to groups that consumed 1) 0.8 g total protein/kg body weight/day from mixed food sources (normal protein control, n = 16); 2) 1.4 g/kg/d protein from mixed food sources (high protein control, n = 17); or 3) 1.4 g/kg/d protein emphasizing unprocessed lean beef (high protein experimental group, n = 16). Participants were provided with all foods and performed RT 3 times/wk, 70% of 1-repetition maximum for 12 wk. We measured quadriceps muscle volume via magnetic resonance imaging (MRI). We estimated patellar tendon biomechanical properties and cross-sectional area (CSA) using ultrasound and MRI., Results: Dietary intake did not influence RT-induced increases in quadriceps strength (P < 0.0001) or muscle volume (P < 0.05). We noted a trend for an RT effect on mean tendon CSA (P = 0.07), with no differences among diets (P > 0.05). Proximal tendon CSA increased with RT (P < 0.05) with no difference between dietary groups (P > 0.05). Among all participants, midtendon CSA increased with RT (P ≤ 0.05). We found a decrease in distal CSA in the 0.8 g group (P < 0.05) but no change in the 1.4 g group (P > 0.05). Patellar tendon MRI signal or biomechanical properties were unchanged., Conclusions: Our findings indicated that greater daily protein intake, emphasizing beef, did not influence RT-induced changes in quadriceps muscle strength or muscle volume of older women. Although we noted trends in tendon CSA, we did not find a statistically significant impact of greater daily protein intake from beef on tendon outcomes. This trial was registered at clinicaltrials.gov as NCT04347447., Competing Interests: Conflict of interest During the time this research was conducted, WWC received funding for research from NIH, USDA, Beef Checkoff, Foundation for Meat and Poultry Research and Education, Pork Checkoff, North Dakota Beef Commission, Barilla Group, Mushroom Council, National Chicken Council, and the Whey Protein Research Consortium. All other authors report no conflicts of interest., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Mushrooms are a nutritious food, though knowledge of the effects of mushroom consumption on cardiometabolic risk factors is limited and inconsistent., Objective: We assessed the effects of consuming mushrooms as part of a healthy United States Mediterranean-style dietary pattern (MED) on traditional and emerging cardiometabolic disease (CMD) risk factors. We hypothesized that adopting a MED diet with mushrooms would lead to greater improvements in multiple CMD risk factors., Methods: Using a randomized, parallel study design, 60 adults (36 females, 24 males; aged 46 ± 12 y; body mass index 28.3 ± 2.84 kg/m 2 , mean ± standard deviation) without diagnosed CMD morbidities consumed a MED diet (all foods provided) without (control with breadcrumbs) or with 84 g/d of Agaricus bisporus (White Button, 4 d/wk) and Pleurotus ostreatus (Oyster, 3 d/wk) mushrooms for 8 wk. Fasting baseline and postintervention outcome measurements were traditional CMD risk factors, including blood pressure and fasting serum lipids, lipoproteins, glucose, and insulin. Exploratory CMD-related outcomes included lipoprotein particle sizes and indexes of inflammation., Results: Adopting the MED-mushroom diet compared with the MED-control diet without mushrooms improved fasting serum glucose (change from baseline -2.9 ± 1.18 compared with 0.6 ± 1.10 mg/dL; time × group P = 0.034). Adopting the MED diet, independent of mushroom consumption, reduced serum total cholesterol (-10.2 ± 3.77 mg/dL; time P = 0.0001). Concomitantly, there was a reduction in high-density lipoprotein (HDL) cholesterol, buoyant HDL2b, and apolipoprotein A1, and an increase in lipoprotein(a) concentrations (main effect of time P < 0.05 for all). There were no changes in other measured CMD risk factors., Conclusions: Consuming a Mediterranean-style healthy dietary pattern with 1 serving/d of whole Agaricus bisporus and Pleurotus ostreatus mushrooms improved fasting serum glucose but did not influence other established or emerging CMD risk factors among middle-aged and older adults classified as overweight or obese but with clinically normal cardiometabolic health., Trial Registration Number: https://www., Clinicaltrials: gov/study/NCT04259229?term=NCT04259229&rank=1., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Nutrimetabolomics allows for the comprehensive analysis of foods and human biospecimens to identify biomarkers of intake and begin to probe their associations with health. Salmon contains hundreds of compounds that may provide cardiometabolic benefits., Objectives: We used untargeted metabolomics to identify salmon food-specific compounds (FSCs) and their predicted metabolites that were found in plasma after a salmon-containing Mediterranean-style (MED) diet intervention. Associations between changes in salmon FSCs and changes in cardiometabolic health indicators (CHIs) were also explored., Methods: For this secondary analysis of a randomized, crossover, controlled feeding trial, 41 participants consumed MED diets with 2 servings of salmon per week for 2 5-wk periods. CHIs were assessed, and fasting plasma was collected pre- and postintervention. Plasma, salmon, and 99 MED foods were analyzed using liquid chromatography-mass spectrometry-based metabolomics. Compounds were characterized as salmon FSCs if detected in all salmon replicates but none of the other foods. Metabolites of salmon FSCs were predicted using machine learning. For salmon FSCs and metabolites found in plasma, linear mixed-effect models were used to assess change from pre- to postintervention and associations with changes in CHIs., Results: Relative to the other 99 MED foods, there were 508 salmon FSCs with 237 unique metabolites. A total of 143 salmon FSCs and 106 metabolites were detected in plasma. Forty-eight salmon FSCs and 30 metabolites increased after the intervention (false discovery rate <0.05). Increases in 2 annotated salmon FSCs and 2 metabolites were associated with improvements in CHIs, including total cholesterol, low-density lipoprotein cholesterol, triglycerides, and apolipoprotein B., Conclusions: A data-driven nutrimetabolomics strategy identified salmon FSCs and their predicted metabolites that were detectable in plasma and changed after consumption of a salmon-containing MED diet. Findings support this approach for the discovery of compounds in foods that may serve, upon further validation, as biomarkers or act as bioactive components influential to health. The trials supporting this work were registered at NCT02573129 (Mediterranean-style diet intervention) and NCT05500976 (ongoing clinical trial)., (Copyright © 2023 American Society for Nutrition. All rights reserved.)

Background & Aims: Recent evidence suggests that the ability to regulate glucose and insulin homeostasis is different in men and women. Against this background, it has been hypothesized that the impact on daily plasma glucose and insulin profiles of the glycemic index (GI) of the habitual diet may differ according to sex. The aim of this study is to evaluate whether 8-h average plasma glucose and insulin profiles during a low- or a high-GI diet in individuals at high risk of developing type 2 diabetes are influenced by sex., Methods: We conducted a randomized, controlled, parallel group dietary intervention, comparing high-versus low-GI diets in a multi-national (Italy, Sweden, and the United States) sample of 156 adults at risk for type 2 diabetes. For 12 weeks, 82 vs 74 participants consumed either a low-GI or high-GI Mediterranean diet, respectively. The two experimental diets contained the same quantity of available carbohydrate (270 g/d) and fiber (35 g/d) and the same foods and beverages, except for the major sources of starch that was specific to the low-GI and high-GI groups (pasta, brown rice, flatbread, all bran, and wheat bread plus rye and seeds, vs jasmine rice, potato, couscous, wholegrain bread, and rusks). At baseline and after the intervention plasma glucose and insulin profiles were evaluated for 8 h in the two intervention groups - separately for men and women - with both breakfast and lunch resembling food choices of the assigned diet., Results: One hundred fifty-six adults (82 women, 74 men) with at least two traits of the metabolic syndrome completed the intervention. In women, the high-GI induced significantly higher (23%, p < 0.05) 8-h average plasma glucose concentrations in comparison to the low-GI diet already on the first day of the intervention; the difference increased up to 37% (p < 0.05) after 12 weeks of diet. Conversely, there were no significant differences between the two diets in men. These results were confirmed by the two-way analysis of variance showing a statistically significant interaction between the effects of sex and diet on the glucose profile after breakfast and lunch (F = 7.887, p = 0.006)., Conclusion: The results of our intervention show that women, compared to men, are more sensitive to the metabolic effects of the dietary GI. This has a strong clinical and scientific relevance and, if confirmed in further studies, it might have important implications for dietary strategies for diabetes and cardiovascular disease prevention in the context of personalized nutrition., Registration Number of Clinical Trial: Clinicaltrials.gov n. NCT03410719., Competing Interests: Conflict of interest G.R. is a member of the Scientific Advisory Board of the Nutrition Foundation of Italy and of the Istituto Nutrizionale Carapelli Foundation; he is a member of the Health and Wellbeing Advisory Board of the Barilla G. e R. Fratelli Company. R.B. is currently employed by ADM. Research presented in this paper was conducted in a former role and has no connection with ADM., (Copyright © 2023 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.)

Background: Limited research evidence exists on the effects of red meat on gut microbiota in human adults., Objective: We aim to assess the effects of consuming a Healthy U.S.-Style Dietary Pattern (HDP), without or with unprocessed or processed lean red meats, on gut microbiota and fecal short-chain fatty acid (SCFA) levels in healthy young adults. Secondary outcomes are cardiovascular disease risk factors., Methods: We conducted a randomized, controlled, crossover trial with 3 3-wk dietary interventions, each separated by a 5-wk washout period with habitual dietary intake. Nineteen participants (8 females, age 26 ± 4 y old, BMI 23 ± 3 kg/m 2 ) consumed 3 study diets in random order: 1) healthy lacto-ovo vegetarian diet (LOV); 2) LOV plus 3 ounces/d of cooked unprocessed lean red meat (URM); and 3) LOV plus 3 ounces/d of cooked processed lean red meat (PRM). Fecal and fasting blood samples were collected before and during the last 2 wk of each intervention. We measured fecal bacterial community structure using 16S rRNA amplicon sequencing (V4 region, primers 515F-806R). Community diversity, structure, and taxonomic composition were computed using Mothur v.1.44.3., Results: The addition of unprocessed or processed lean red meats to a LOV HDP did not influence short-term changes in bacterial taxonomic composition. Independent of red meat intake, the HDP led to changes in 23 bacteria; reductions in serum total cholesterol (TC) and LDL-C concentrations; but no changes in fecal SCFA, serum triglycerides, HDL-C concentrations, TC/HDL-C ratio, or blood pressures. With data from all 3 diet interventions combined, changes in some bacteria were associated with improvements in TC, LDL-C, triglycerides, and HDL-C concentrations, and TC/HDL-C ratio., Conclusions: Healthy young adults who adopt an HDP that may be vegetarian or omnivorous, including lean red meat, experience short-term changes in gut microbial composition, which associate with improvements in multiple lipid-related cardiovascular risk factors. NCT03885544, https://clinicaltrials.gov/ct2/show/NCT03885544?cond=NCT03885544&draw=2&rank=1., (Copyright © 2023 American Society for Nutrition. Published by Elsevier Inc. All rights reserved.)

Emerging research indicates the importance of gut microbiota in mediating the relationship between meat intake and human health outcomes. We aimed to assess the state of available scientific literature on meat intake and gut microbiota in humans (PROSPERO, International Prospective Register of Systematic Reviews, CRD42020135649). We first conducted a scoping review to identify observational and interventional studies on this topic. Searches were performed for English language articles using PubMed, Cochrane Library, Scopus, and CINAHL (Cumulated Index to Nursing and Allied Health Literature) databases from inception to August 2021 and using keywords related to meat (inclusive of mammalian, avian, and aquatic subtypes) and gut microbiota. Of 14,680 records, 85 eligible articles were included in the scoping review, comprising 57 observational and 28 interventional studies. One prospective observational study and 13 randomized controlled trials (RCTs) were identified in adults without diagnosed disease. We included the 13 RCTs, comprising 18 comparisons, in the systematic review to assess the effects of higher and lower intakes of total meat and meat subtypes on the gut microbiota composition. The bacterial composition was differentially affected by consuming diets with and without meat or with varied meat subtypes. For example, higher meat intake tended to decrease population sizes of genera Anerostipes and Faecalibacterium, but it increased the population size of Roseburia across studies. However, the magnitude and directionality of most microbial responses varied, with inconsistent patterns of responses across studies. The data were insufficient for comparison within or between meat subtypes. The paucity of research, especially among meat subtypes, and heterogeneity of findings underscore the need for more well-designed prospective studies and full-feeding RCTs to address the relationships between and effects of consuming total meat and meat subtypes on gut microbiota, respectively., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)

This review is a tribute to honor Dr Douglas Paddon-Jones by highlighting his career research contributions. Dr Paddon-Jones was a leader in recognizing the importance of muscle health and the interactions of physical activity and dietary protein for optimizing the health span. Aging is characterized by loss of muscle mass and strength associated with reduced rates of muscle protein synthesis (MPS) and the ability to repair and replace muscle proteins. Research from the team at the University of Texas Medical Branch in Galveston discovered that the age-related decline in MPS could be overcome by increasing the quantity or quality of dietary protein at each meal. Dr Paddon-Jones was instrumental in proposing and testing a "protein threshold" of ∼30 g protein/meal to optimize MPS in older adults. Dr Paddon-Jones demonstrated that physical inactivity greatly accelerates the loss of muscle mass and function in older adults. His work in physical activity led him to propose the "Catabolic Crisis Model" of muscle size and function losses, suggesting that age-related muscle loss is not a linear process, but the result of acute periods of disuse associated with injuries, illnesses, and bed rest. This model creates the opportunity to provide targeted interventions via protein supplementation and/or increased dietary protein through consuming high-quality animal-source foods. He illustrated that nutritional support, particularly enhanced protein quantity, quality, and meal distribution, can help preserve muscle health during periods of inactivity and promote health across the life course., (Copyright © 2023 American Society for Nutrition. Published by Elsevier Inc. All rights reserved.)

This scoping review was conducted to systematically search and chronicle scientific literature pertinent to poultry intake and human health. The protocol (uploaded to Open Science Framework, https://osf.io/2k7bj/) was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews guidelines. Articles with observational and experimental research, narrative and systematic reviews, and meta-analyses were included. Among 13,141 articles identified, 525 met inclusion criteria. Among these 525 articles, 212 focused on cancer morbidity and mortality; 41 on cardiovascular disease (CVD) morbidity and mortality; 52 on CVD risk factors; 32 on type 2 diabetes mellitus (T2DM) morbidity and mortality; 33 on T2DM risk factors; and 42 on body weight and body composition. An "Other" category (181 articles) included nutrient status, psychological well-being/mental health, cognition, microbiome, chronic kidney disease, nonalcoholic fatty liver disease, skin disorders, and fertility, among others. Among the 525 included articles, 366 were observational, 64 were experimental, and 76 were reviews and meta-analyses. Eighty-three percent of articles focused on adults or older adults. A paucity of research exists to support poultry as health-promoting foods, with most research only indirectly assessing poultry intake compared with other foods of interest (e.g., red meats or plant-based protein foods). No randomized controlled trials and only 1% of OBS assessed the influence of processed poultry intake on human health. In the future, the relative health effects of consuming poultry will be compared with a widening array of traditional and new protein-rich food products, necessitating the need for research to assess poultry as foods of choice. Science and health professionals, the poultry industry, and the public will benefit from new observational and experimental research to address cutting-edge scientific, public policy, and consumer topics pertinent to poultry intake and human health., (© The Author(s) 2022. Published by Oxford University Press on behalf of the American Society for Nutrition.)

Background: Sarcopenia, a progressive loss of skeletal muscle mass and strength, can begin in the 4th decade of life. Protein intake predicts skeletal muscle mass and strength among older adults, but knowledge of similar associations among middle-aged adults is lacking., Objectives: We aimed to assess associations between protein intake and skeletal muscle mass, characterized by appendicular lean mass adjusted for BMI [in kg/m2 (ALMBMI)], and muscle strength, represented by handgrip strength adjusted for BMI (GSMAXBMI), among middle-aged adults., Methods: We analyzed cross-sectional data from 1209 men and 1208 women aged 40-59 y in the 2011-2014 NHANES. Protein intake per kilogram actual body weight (BW), assessed by two 24-h recalls, was examined as continuous and categorical parameters [low (

Our objective was to conduct a systematic review and meta-analysis to assess the effects of total red meat (TRM) intake on glycemic control and inflammatory biomarkers using randomized controlled trials of individuals free from cardiometabolic disease. We hypothesized that higher TRM intake would negatively influence glycemic control and inflammation based on positive correlations between TRM and diabetes. We found 24 eligible articles (median duration, 8 weeks) from 1172 articles searched in PubMed, Cochrane, and CINAHL up to August 2019 that included 1) diet periods differing in TRM; 2) participants aged ≥19 years; 3) included either men or women who were not pregnant/lactating; 4) no diagnosed cardiometabolic disease; and 5) data on fasting glucose, insulin, HOMA-IR, glycated hemoglobin (HbA1c), C-reactive protein (CRP), or cytokines. We used 1) a repeated-measures ANOVA to assess pre to post diet period changes; 2) random-effects meta-analyses to compare pre to post changes between diet periods with ≥ vs. <0.5 servings (35g)/day of TRM; and 3) meta-regressions for dose-response relationships. We grouped diet periods to explore heterogeneity sources, including risk of bias, using the National Heart, Lung, and Blood Institute's Quality Assessment of Controlled Interventions Studies. Glucose, insulin, and HOMA-IR values decreased, while HbA1c and CRP values did not change during TRM or alternative diet periods. There was no difference in change values between diet periods with ≥ vs. <0.5 servings/day of TRM [weighted mean differences (95% CIs): glucose, 0.040 mmol/L (-0.049, 0.129); insulin, -0.710 pmol/L (-6.582, 5.162); HOMA-IR, 0.110 (-0.072, 0.293); CRP, 2.424 nmol/L (-1.460, 6.309)] and no dose response relationships (P > 0.2). Risk of bias (85% of studies were fair to good) did not influence results. Total red meat consumption, for up to 16 weeks, does not affect changes in biomarkers of glycemic control or inflammation for adults free of, but at risk for, cardiometabolic disease. This trial was registered at PROSPERO as 2018 CRD42018096031., (Copyright © The Author(s) on behalf of the American Society for Nutrition 2020.)

Background: Limited evidence suggests that consuming a higher-protein diet during weight loss improves subjective indices of sleep in overweight and obese adults., Objective: We sought to a priori assess the effects of consuming the recommended versus a higher protein Healthy US-Style Eating Pattern during energy-restriction on sleep quality indices., Design: Using a randomized, parallel study design, 51 adults (mean ± SEM age: 47 ± 1 y; BMI: 32.6 ± 0.5 kg/m2) consumed a controlled USDA Healthy US-Style Eating Pattern containing 750 kcal/d less than their estimated energy requirement for 12 wk. Participants were randomly assigned to consume either 5 or 12.5 oz-equivalent (eq)/d of protein foods. The additional 7.5 oz-eq/d came from animal-based protein sources and displaced primarily grains. Objective (wrist-worn actigraphy) and subjective (Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale) sleep quality indices were measured at baseline, week 6, and week 12., Results: Among all participants, body mass decreased (-6.2 ± 0.4 kg). Dietary protein intake did not affect any objective or subjective sleep quality outcomes measured (repeated measures ANOVA). Over time, objective measures of time spent in bed, time spent sleeping, sleep onset latency, and time awake after sleep onset did not change; however, sleep efficiency improved (1 ± 1%; P = 0.027). Subjectively, global sleep scores [GSS: -2.7 ± 0.4 arbitrary units (au)] and daytime sleepiness scores (-3.8 ± 0.4 au; both P < 0.001) improved over time. The GSS improvement transitioned the participants from being categorized with "poor" to "good" sleep (GSS: >5 compared with ≤5 au of a 0-21 au scale; baseline 7.6 ± 0.4 au, week 12: 4.8 ± 0.4 au)., Conclusions: Although objective sleep quality may not improve, adults who are overweight or obese and poor sleepers may become good sleepers while consuming either the recommended or a higher-protein energy-restricted Healthy US-Style Eating Pattern. This trial was registered at clinicaltrials.gov as NCT03174769., (© The Author(s) 2020. Published by Oxford University Press on behalf of the American Society for Nutrition.)

Under stressful conditions such as energy restriction (ER) and physical activity, the RDA for protein of 0.8 g · kg-1 · d-1 may no longer be an appropriate recommendation. Under catabolic or anabolic conditions, higher protein intakes are proposed to attenuate the loss or increase the gain of whole-body lean mass, respectively. No known published meta-analysis compares protein intakes greater than the RDA with intakes at the RDA. Therefore, we conducted a systematic review and meta-analysis to assess the effects of protein intakes greater than the RDA, compared with at the RDA, on changes in whole-body lean mass. Three researchers independently screened 1520 articles published through August 2018 using the PubMed, Scopus, CINAHL, and Cochrane databases, with additional articles identified in published systematic review articles. Randomized, controlled, parallel studies ≥6 wk long with apparently healthy adults (≥19 y) were eligible for inclusion. Data from 18 studies resulting in 22 comparisons of lean mass changes were included in the final overall analysis. Among all comparisons, protein intakes greater than the RDA benefitted changes in lean mass relative to consuming the RDA [weighted mean difference (95% CI): 0.32 (0.01, 0.64) kg, n = 22 comparisons]. In the subgroup analyses, protein intakes greater than the RDA attenuated lean mass loss after ER [0.36 (0.06, 0.67) kg, n = 14], increased lean mass after resistance training (RT) [0.77 (0.23, 1.31) kg, n = 3], but did not differentially affect changes in lean mass [0.08 (-0.59, 0.75) kg, n = 7] under nonstressed conditions (no ER + no RT). Protein intakes greater than the RDA beneficially influenced changes in lean mass when adults were purposefully stressed by the catabolic stressor of dietary ER with and without the anabolic stressor of RT. The RDA for protein is adequate to support lean mass in adults during nonstressed states. This review was registered at www.crd.york.ac.uk/prospero as CRD 42018106532., (Copyright © The Author(s) 2019.)

This systematic review and landscape analysis describes patterns in dietary meat (skeletal muscle and associated tissues from mammalian, avian, and aquatic species; i.e., muscle foods) categories (CAT) and descriptions (DESCR) used throughout nutrition-related chronic disease literature, as there is anecdotally noted variation. A total of 1020 CAT and 776 DESCR were identified from 369 articles that assessed muscle food consumption and primary prevention of cardiovascular disease, obesity, type 2 diabetes, or cancer in adults ≥19 y from PubMed, Cochrane, and CINAHL up to March 2018. Specificity of CAT was analyzed on an empirical 1-7 ordinal scale as: 1) broad/undescriptive, "fish"; 2) muscle food type, "red meat"; 3) species, "poultry"; 4) broad + 1 descriptor, "processed meat"; 5) type/species + 1 descriptor, "fresh red meat"; 6) broad/type + 2 descriptors, "poached lean fish"; and 7) specific product, "luncheon meat." Median CAT specificity for randomized controlled trials (RCTs) and observational studies (OBSs) was 3 and 2 points out of 7, respectively, with no differences between chronic disease types. Specificity of OBS CAT was higher in recent articles but RCT CAT became less specific starting in the 2000s. RCT CAT were 400% more likely to include species, 500% more likely to include leanness, but 400% less likely to include processing degree compared with OBS CAT. A DESCR was included for 76% and 82% of OBS and RCT CAT, respectively. Researchers described processed meat, red meat, and total meat CAT more commonly than poultry or fish CAT. Among processed meat DESCR, 31% included a common term used in public regulatory definitions. In conclusion, muscle food categories and descriptions are substantively different within and between experimental and observational studies and do not match regulatory definitions. A practical muscle food classification system is warranted to improve interpretation of evidence regarding muscle food consumption and chronic disease., (Copyright © American Society for Nutrition 2019.)

Research supports the hypothesis that higher total protein intake during weight loss promotes retention of lean soft tissue, but the effect of dietary protein quantity on bone mass, a lean hard tissue, is inconsistent. The purpose of this systematic review and meta-analysis was to assess the effect of dietary protein quantity [higher protein (HP): ≥25% of energy from protein or ≥1.0 g · kg body wt-1 · d-1; normal protein (NP): <25% of energy from protein or <1.0 g · kg body wt-1 · d-1] on changes in bone mineral density (BMD) and content (BMC; total body, lumbar spine, total hip, femoral neck) following a prescribed energy restriction. We hypothesized that an HP diet would attenuate the loss of BMD/BMC following weight loss in comparison to an NP diet. Two researchers systematically and independently screened 2366 publications from PubMed, Cochrane, Scopus, CINAHL, and Web of Science Core Collection and extracted data from 34 qualified publications. Inclusion criteria included the following: 1) healthy subjects ≥19 y; 2) a prescribed energy restriction; 3) measurements of total protein intake, BMD, and BMC; and 4) an intervention duration of ≥3 mo. Data from 10 of the 34 publications with 2 groups of different total protein intakes were extracted and used to conduct a random-effects model meta-analysis. A majority of publications (59%) showed a decrease in bone quantity following active weight loss, regardless of total protein intake. Statistically, the loss of total BMD (P = 0.016; weighted mean difference: +0.006 g/cm2; 95% CI: 0, 0.011 g/cm2) and lumbar spine BMD (P = 0.019; weighted mean difference: +0.017 g/cm2; 95% CI: 0.001, 0.033 g/cm2) was attenuated with an HP versus an NP weight-loss diet. However, the clinical significance is questionable given the modest weighted mean difference and study duration. Higher total protein intake does not exacerbate but may attenuate the loss of bone quantity following weight loss., (Copyright © American Society for Nutrition 2019.)

Background: Reducing red meat intake is commonly recommended. Limited observational studies suggest that healthy eating patterns with red meat are associated with improved quality of life., Objective: The secondary objectives of this randomized crossover controlled-feeding trial were to assess the effects of following a Mediterranean-style eating pattern (Med-Pattern) with different amounts of red meat on indexes of personal well-being (i.e., perceived quality of life, mood, and sleep) in overweight or obese adults. We hypothesized that following a Med-Pattern would improve these outcomes, independent of red meat intake amount., Methods: Forty-one participants [aged 46 ± 2 y; body mass index (kg/m2): 30.5 ± 0.6; n = 28 women, n = 13 men) were provided Med-Pattern foods for two 5-wk periods separated by 4 wk of self-selected eating. The Med-Red Pattern contained ∼500 g/wk (typical US intake), and the Med-Control Pattern contained ∼200 g/wk (commonly recommended intake in heart-healthy eating patterns) of lean, unprocessed beef or pork compensated with mainly poultry and dairy. Baseline and postintervention outcomes measured were perceived quality of life via the MOS 36-Item Short-Form Health Survey, version 2 (SF-36v2), daily mood states via the Profile of Mood States (POMS), sleep perceptions via the Pittsburgh Sleep Quality Index, and sleep patterns via actigraphy. Data were analyzed via a doubly repeated-measures ANOVA adjusted for age, sex, and body mass at each time point., Results: Following a Med-Pattern did not change domains of physical health, mental health, total mood disturbances, sleep perceptions, and sleep patterns but improved subdomains of physical health role limitations (SF-36v2: 93.6-96.7%; P = 0.038), vitality (SF-36v2: 57.9-63.0%; P = 0.020), and fatigue (POMS: 2.9-2.5 arbitrary units; P = 0.039). There were no differences between the Med-Red and Med-Control Patterns (time × pattern, P-interaction > 0.05)., Conclusion: Following a Med-Pattern, independent of lean, unprocessed red meat intake, may not be an effective short-term strategy to meaningfully improve indexes of personal well-being in adults who are overweight or obese. This trial was registered at clinicaltrials.gov as NCT02573129.

Background: A Mediterranean-style eating pattern (Mediterranean Pattern) is often described as being low in red meat. Research shows that lean, unprocessed red meat can be incorporated into healthy eating patterns to improve cardiometabolic disease (CMD) risk factors., Objective: We assessed the effects of consuming different amounts of lean, unprocessed red meat in a Mediterranean Pattern on CMD risk factors. We hypothesized that consuming a Mediterranean Pattern would improve CMD risk factors and that red meat intake would not influence these improvements., Design: In an investigator-blinded, randomized, crossover, controlled feeding trial, 41 subjects [mean ± SD age: 46 ± 2 y; mean ± SD body mass index (kg/m2): 30.5 ± 0.6] were provided with a Mediterranean Pattern for two 5-wk interventions separated by 4 wk of self-selected eating. The Mediterranean Patterns contained ∼500 g [typical US intake (Med-Red)] and ∼200 g [commonly recommended intake in heart-healthy eating patterns (Med-Control)] of lean, unprocessed beef or pork per week. Red meat intake was compensated by poultry and other protein-rich foods. Baseline and postintervention outcomes included fasting blood pressure, serum lipids, lipoproteins, glucose, insulin, and ambulatory blood pressure. The presented results were adjusted for age, sex, and body mass at each time point (P < 0.05)., Results: Total cholesterol decreased, but greater reductions occurred with Med-Red than with Med-Control (-0.4 ± 0.1 and -0.2 ±0.1 mmol/L, respectively, intervention × time = 0.045]. Low-density lipoprotein decreased with Med-Red but was unchanged with Med-Control [-0.3 ± 0.1 and -0.1 ± 0.1 mmol/L, respectively, intervention × time = 0.038], whereas high-density lipoprotein (HDL) concentrations decreased nondifferentially [-0.1 ± 0.0 mmol/L]. Triglycerides, total cholesterol:HDL, glucose, and insulin did not change with either Med-Red or Med-Control. All blood pressure parameters improved, except during sleep, independent of the red meat intake amount., Conclusions: Adults who are overweight or moderately obese may improve multiple cardiometabolic disease risk factors by adopting a Mediterranean-style eating pattern with or without reductions in red meat intake when red meats are lean and unprocessed. This trial was registered at clinicaltrials.gov as NCT02573129.

Background: Emerging research suggests that redistributing total protein intake from 1 high-protein meal/d to multiple moderately high-protein meals improves 24-h muscle protein synthesis. Over time, this may promote positive changes in body composition. Objective: We sought to assess the effects of within-day protein intake distribution on changes in body composition during dietary energy restriction and resistance training. Design: In a randomized parallel-design study, 41 men and women [mean ± SEM age: 35 ± 2 y; body mass index (in kg/m 2 ): 31.5 ± 0.5] consumed an energy-restricted diet (750 kcal/d below the requirement) for 16 wk while performing resistance training 3 d/wk. Subjects consumed 90 g protein/d (1.0 ± 0.03 g · kg -1 · d -1 , 125% of the Recommended Dietary Allowance, at intervention week 1) in either a skewed (10 g at breakfast, 20 g at lunch, and 60 g at dinner; n = 20) or even (30 g each at breakfast, lunch, and dinner; n = 21) distribution pattern. Body composition was measured pre- and postintervention. Results: Over time, whole-body mass (least-squares mean ± SE: -7.9 ± 0.6 kg), whole-body lean mass (-1.0 ± 0.2 kg), whole-body fat mass (-6.9 ± 0.5 kg), appendicular lean mass (-0.7 ± 0.1 kg), and appendicular fat mass (-2.6 ± 0.2 kg) each decreased. The midthigh muscle area (0 ± 1 cm 2 ) did not change over time, whereas the midcalf muscle area decreased (-3 ± 1 cm 2 ). Within-day protein distribution did not differentially affect these body-composition responses. Conclusion: The effectiveness of dietary energy restriction combined with resistance training to improve body composition is not influenced by the within-day distribution of protein when adequate total protein is consumed. This trial was registered at clinicaltrials.gov as NCT02066948., (© 2017 American Society for Nutrition.)

The dietary protein allowance for older men to maintain lean body mass and muscle strength and to accrue optimal anabolic responses to promyogenic stimuli is poorly characterized. The OPTIMEN trial was designed to assess in older men with moderate physical dysfunction and insufficient habitual protein intake (-1 ·d -1 ) the efficacy of consuming diets containing 163% RDA (1.3g·kg -1 ·d -1 ) for protein, compared to RDA, to increase lean mass, muscle performance, and physical function. A second aim was to determine whether increasing protein intake to 1.3 versus 0.8g·kg -1 ·d -1 would augment anabolic responses to a promyogenic agent, testosterone. For this randomized, double-blind, placebo-controlled six-month intervention trial, 92 men, 65years or older, with Short Physical Performance Battery scores 3-10, and habitual protein intakes

Background: In the United States, 17% of children are currently obese. Increasing feelings of fullness may prevent excessive energy intake, lead to better diet quality, and promote long-term maintenance of healthy weight. Objective: The purpose of this study was to develop a fullness-rating tool (aim 1) and to determine whether a high-protein (HP), high-fiber (HF), and combined HP and HF (HPHF) breakfast increases preschoolers' feelings of fullness before (pre) and after (post) breakfast and pre-lunch, as well as their diet quality, as measured by using a composite diet quality assessment tool, the Revised Children's Diet Quality Index (aim 2). Methods: Children aged 4 and 5 y ( n = 41; 22 girls and 19 boys) from local Head Start centers participated in this randomized intervention trial. Sixteen percent of boys and 32% of girls were overweight or obese. After the baseline week, children rotated through four 1-wk periods of consuming ad libitum HP (19-20 g protein), HF (10-11 g fiber), HPHF (19-21 g protein, 10-12 g fiber), or usual (control) breakfasts. Food intake at breakfast was estimated daily, and for breakfast, lunch, and snack on day 3 of each study week Student's t tests and ANOVA were used to determine statistical differences. Results: Children's post-breakfast and pre-lunch fullness ratings were ≥1 point higher than those of pre-breakfast (aim 1). Although children consumed, on average, 65 kcal less energy during the intervention breakfasts ( P < 0.007) than during the control breakfast, fullness ratings did not differ ( P = 0.76). Relative to the control breakfast, improved diet quality (12%) was calculated for the HP and HF breakfasts ( P < 0.027) but not for the HPHF breakfast (aim 2). Conclusions: Post-breakfast fullness ratings were not affected by the intervention breakfasts relative to the control breakfast. HP and HF breakfasts resulted in higher diet quality. Serving HP or HF breakfasts may be valuable in improving diet quality without lowering feelings of satiation or satiety. This trial was registered at clinicaltrials.gov as NCT02122224., (© 2017 American Society for Nutrition.)

Background: Controversy exists concerning the effects of higher total protein intake (TPro) on bone health, which may be associated with reduced bone mineral density (BMD). However, whey protein (WP) may induce bone formation because of its basic component, milk basic protein., Objective: This study assessed the effects of WP supplementation, TPro, and change in TPro (postsupplementation - presupplementation) on BMD and bone mineral content (BMC; total body, lumbar spine, total femur, and femoral neck) in overweight and class I obese middle-aged adults following an exercise intervention., Methods: This analysis used data from a double-blind, randomized, placebo-controlled 36-wk WP supplementation trial, wherein participants consumed a 1.7-MJ (400-kcal) supplement (0, 20, 40, or 60 g WP/d) along with their otherwise unrestricted diet while participating in a resistance and aerobic exercise intervention (3 d/wk). TPro was the summation of WP and habitual dietary intakes (4-d food record). Statistical analyses for WP were based on group and bone data [n = 186, 108 women; mean ± SD age: 49 ± 8 y; body mass index (BMI; in kg/m 2 ): 30.1 ± 2.8], whereas TPro was based on dietary and bone data (n = 113, 70 women; age 50 ± 8 y; BMI 30.1 ± 2.9)., Results: WP supplementation, regardless of dose, did not influence BMD or BMC following the intervention. By using a multiple linear regression model, TPro (expressed as g/d or g · kg -1 · d -1 ) and change in TPro (expressed as g/d) were not associated with responses over time in total or regional BMD or BMC. By using a cluster analysis approach [<1.0 (n = 41), 1.0-1.2 (n = 28), and ≥1.2 g · kg -1 · d -1 (n = 44)], TPro was also not associated with responses in total or regional BMD or BMC over time., Conclusion: WP supplementation and total dietary protein intake did not negatively or beneficially influence bone quantity in overweight and obese adults during a 9-mo exercise intervention. This trial was registered at clinicaltrials.gov as NCT00812409., Competing Interests: 3 Author disclosures: CS Wright, AM McMorrow, and EM Weinheimer-Haus, no conflicts of interest. WW Campbell was a member of the National Dairy Council Whey Protein Advisory Panel while the current research was being conducted., (© 2017 American Society for Nutrition.)

Background: Youth-onset type 2 diabetes (T2D) is a disease that is newly emerging and behavioral strategies for its prevention are limited. Interventions that target the lifestyle behaviors of adolescents, to improve poor dietary quality and reduce excessive sedentariness, promise to reduce the risk of developing T2D. Health coaching is effective for promoting healthy behaviors in patients who have chronic disease, but few experimental studies are in adolescents. This randomized controlled trial, in adolescents with prediabetes, will determine the effectiveness of a health coaching intervention to facilitate adoption of healthy diet and activity behaviors that delay or prevent development of T2D., Methods/design: The Dietary Intervention for Glucose Tolerance In Teens (DIG IT) trial will involve an evaluation of a health coaching intervention in adolescents with prediabetes. Eligible participants will be randomized to receive 6months of health coaching or a single dietary consultation that is standard-of-care. The primary outcome will be 2-hour oral glucose tolerance test concentration. Secondary outcomes will include measures of glycemia and insulin action as well as dietary, physical activity and sedentary behaviors measured using an electronic food record, and by inclinometer. Data will be collected before and after the intervention (at 6months) and at 12months (to assess sustainability)., Discussion: This trial will determine whether a health coaching intervention, a personalized and low-cost approach to modify dietary and activity behaviors, is effective and sustainable for prevention of youth-onset T2D, relative to standard-of-care. Health coaching has the potential to be widely implemented in clinical or community settings., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: Observational associations between red meat intake and cardiovascular disease (CVD) are inconsistent. There are limited comprehensive analyses of randomized controlled trials (RCTs) that investigate the effects of red meat consumption on CVD risk factors., Objective: The purpose of this systematically searched meta-analysis was to assess the effects of consuming ≥0.5 or <0.5 servings of total red meat/d on CVD risk factors [blood total cholesterol (TC), LDL cholesterol, HDL cholesterol, triglycerides, ratio of TC to HDL cholesterol (TC:HDL), and systolic and diastolic blood pressures (SBP and DBP, respectively)]. We hypothesized that the consumption of ≥0.5 servings of total red meat/d would have a negative effect on these CVD risk factors., Design: Two researchers independently screened 945 studies from PubMed, Cochrane Library, and Scopus databases and extracted data from 24 qualified RCTs. Inclusion criteria were 1) RCT, 2) subjects aged ≥19 y, 3) consumption of ≥0.5 or <0.5 total red meat servings/d [35 g (1.25 ounces)], and 4) reporting ≥1 CVD risk factor. We performed an adjusted 2-factor nested ANOVA mixed-effects model procedure on the postintervention values of TC, LDL cholesterol, HDL cholesterol, TC:HDL cholesterol, triglycerides, SBP, and DBP; calculated overall effect sizes of change values; and used a repeated-measures ANOVA to assess pre- to postintervention changes., Results: Red meat intake did not affect lipid-lipoprotein profiles or blood pressure values postintervention (P > 0.05) or changes over time [weighted mean difference (95% CI): -0.01 mmol/L (-0.08, 0.06 mmol/L), 0.02 mmol/L (-0.05, 0.08 mmol/L), 0.03 mmol/L (-0.01, 0.07 mmol/L), and 0.04 mmol/L (-0.02, 0.10 mmol/L); -0.08 mm Hg (-0.26, 0.11 mm Hg); and -1.0 mm Hg (-2.4, 0.78 mm Hg) and 0.1 mm Hg (-1.2, 1.5 mm Hg) for TC, LDL cholesterol, HDL cholesterol, triglycerides, TC:HDL cholesterol, SBP, and DBP, respectively]. Among all subjects, TC, LDL cholesterol, HDL cholesterol, TC:HDL cholesterol, triglycerides, and DBP, but not SBP, decreased over time (P < 0.05)., Conclusions: The results from this systematically searched meta-analysis of RCTs support the idea that the consumption of ≥0.5 servings of total red meat/d does not influence blood lipids and lipoproteins or blood pressures., (© 2017 American Society for Nutrition.)

Background: Most people living in the United States underconsume vitamin E, and dietary approaches to increase the absorption of vitamin E may help individuals to meet their body's needs., Objective: We assessed the effect of adding cooked whole egg to a raw mixed-vegetable salad on α-tocopherol and γ-tocopherol absorption., Methods: With the use of a randomized-crossover design, 16 healthy young men [mean ± SD age: 24 ± 4 y; mean ± SD body mass index (in kg/m 2 ): 24 ± 2] consumed the same salad (all served with 3 g canola oil) with no egg [control (CON)], with 75 g cooked egg [low egg (LE)], or with 150 g cooked egg [high egg (HE)]; a 1-wk dietary washout period was included between trials. For the first 7 d of each trial, participants consumed a low-vitamin E diet to reduce plasma vitamin E concentrations. Blood was collected hourly for 10 h and the triacylglycerol-rich lipoprotein fractions (TRLs) were isolated. α-Tocopherol and γ-tocopherol concentrations in TRLs were analyzed and composite areas under the curve (AUCs) were calculated., Results: The α-tocopherol 0- to 10-h AUCs (AUCs 0-10 h ) in TRLs was higher (P < 0.05) for the HE trial (least-squares mean ± SE: 981 ± 162 nmol/L ⋅ 10 h) than for the LE (311 ± 162 nmol/L ⋅ 10 h) and CON (117 ± 162 nmol/L ⋅10 h) trials, which did not differ from one another. The γ-tocopherol AUCs 0-10 h in TRLs was also higher (P < 0.05) for the HE trial (402 ± 54 nmol/L ⋅ 10 h) than for the CON trial (72 ± 54 nmol/L ⋅ 10 h)., Conclusion: The consumption of cooked whole eggs is an effective way to increase the absorption of α-tocopherol and γ-tocopherol from a co-consumed meal that naturally contains vitamin E, such as a raw mixed-vegetable salad, in healthy young men. This trial was registered at clinicaltrials.gov as NCT01951313., Competing Interests: 2 Author disclosures: JE Kim, MG Ferruzzi, and WW Campbell, no conflicts of interest. Representatives from the American Egg Board–Egg Nutrition Center had no influence on the design, implementation, analysis, or interpretation of data for this investigator-initiated study., (© 2016 American Society for Nutrition.)

The Dietary Guidelines for Americans (DGA) is published every 5 y jointly by the Department of Health and Human Services (HHS) and the USDA and provides a framework for US-based food and nutrition programs, health promotion and disease prevention initiatives, and research priorities. Summarized in this report are the methods, major conclusions, and recommendations of the Scientific Report of the 2015 US Dietary Guidelines Advisory Committee (DGAC). Early in the process, the DGAC developed a conceptual model and formulated questions to examine nutritional risk and determinants and impact of dietary patterns in relation to numerous health outcomes among individuals aged ≥2 y. As detailed in the report, an expansive, transparent, and comprehensive process was used to address each question, with multiple opportunities for public input included. Consensus was reached on all DGAC's findings, including each conclusion and recommendation, and the entire report. When research questions were answered by original systematic literature reviews and/or with existing, high-quality expert reports, the quality and strength of the evidence was formally graded. The report was organized around the following 5 themes: 1) food and nutrient intakes and health: current status and trends; 2) dietary patterns, foods and nutrients, and health outcomes; 3) diet and physical activity behavior change; 4) food and physical activity environments; and 5) food sustainability and food safety. The following 3 cross-cutting topics were addressed: 1) sodium, 2) saturated fat, and 3) added sugars. Physical activity recommendations from recent expert reports were endorsed. The overall quality of the American diet was assessed to identify overconsumed and underconsumed nutrients of public health concern. Common food characteristics of healthy dietary patterns were determined. Features of effective interventions to change individual and population diet and physical activity behaviors in clinical, public health, and community settings were identified. The report was used by the HHS and the USDA to develop the 2015 DGA., (© 2016 American Society for Nutrition.)

Background: Limited and inconsistent research findings exist about the effect of dietary protein intake on indexes of sleep., Objective: We assessed the effect of protein intake during dietary energy restriction on indexes of sleep in overweight and obese adults in 2 randomized, controlled feeding studies., Design: For study 1, 14 participants [3 men and 11 women; mean ± SE age: 56 ± 3 y; body mass index (BMI; in kg/m(2)): 30.9 ± 0.6] consumed energy-restricted diets (a 750-kcal/d deficit) with either beef and pork (BP; n = 5) or soy and legume (SL; n = 9) as the main protein sources for 3 consecutive 4-wk periods with 10% (control), 20%, or 30% of total energy from protein (random order). At baseline and the end of each period, the global sleep score (GSS) was assessed with the use of the Pittsburgh Sleep Quality Index (PSQI) questionnaire. For study 2, 44 participants (12 men and 32 women; age: 52 ± 1 y; BMI: 31.4 ± 0.5) consumed a 3-wk baseline energy-balance diet with 0.8 g protein · kg baseline body mass(-1) · d(-1). Then, study 2 subjects consumed either a normal-protein [NP (control); n = 23] or a high-protein (HP; n = 21) (0.8 compared with 1.5 g · kg(-1) · d(-1), respectively) energy-restricted diet (a 750-kcal/d deficit) for 16 wk. The PSQI was administered during baseline week 3 and intervention weeks 4, 8, 12, and 16. GSSs ranged from 0 to 21 arbitrary units (au), with a higher value representing a worse GSS during the preceding month., Results: In study 1, we showed that a higher protein quantity improved GSSs independent of the protein source. The GSS was higher (P < 0.05) when 10% (6.0 ± 0.4 au) compared with 20% (5.0 ± 0.4 au) protein was consumed, with 30% protein (5.4 ± 0.6 au) intermediate. In study 2, at baseline, the GSS was not different between NP (5.2 ± 0.5 au) and HP (5.4 ± 0.5 au) groups. Over time, the GSS was unchanged for the NP group and improved for the HP group (P-group-by-time interaction < 0.05). After intervention (week 16), GSSs for NP and HP groups were 5.9 ± 0.5 and 4.0 ± 0.6 au, respectively (P < 0.01)., Conclusion: The consumption of a greater proportion of energy from protein while dieting may improve sleep in overweight and obese adults. This trial was registered at clinicaltrials.gov as NCT01005563 (study 1) and NCT01692860 (study 2)., (© 2016 American Society for Nutrition.)

Background: Research indicates that plasma 25-hydroxyvitamin D [25(OH)D] is associated with insulin resistance, but whether regional adiposity confounds this association is unclear., Objective: This study assessed the potential influence of adiposity and its anatomical distribution on the relation between plasma 25(OH)D and insulin resistance., Methods: A secondary analysis of data from middle-aged overweight and obese healthy adults [n = 336: 213 women and 123 men; mean ± SD (range); age: 48 ± 8 y (35-65 y); body mass index (BMI; in kg/m2): 30.3 ± 2.7 (26-35)] from West Lafayette, Indiana (40.4 °N), were used for this cross-sectional analysis. Multiple linear regression analyses that controlled for multiple covariates were used as the primary statistical model., Results: Of all participants, 8.6% and 20.5% displayed moderate [20.1-37.5 nmol/L plasma 25(OH)D] to mild (37.6-49.9 nmol/L) vitamin D insufficiency, respectively. A regression analysis controlling for age, sex, race, plasma parathyroid hormone concentration, season of year, and supplement use showed that 25(OH)D was negatively associated with fasting insulin (P = 0.021). Additional regression analyses showed that total and central adiposity but not peripheral adiposity predicted low plasma 25(OH)D [total fat mass index (FMI): P = 0.018; android FMI: P = 0.052; gynoid FMI: P = 0.15; appendicular FMI: P = 0.07) and insulin resistance (homeostasis model assessment of insulin resistance: total and android FMI, P <0.0001; gynoid FMI, P = 0.94; appendicular FMI, P = 0.86). The associations of total and central adiposity with insulin resistance remained significant after adjusting for plasma 25(OH)D. However, adjusting for central adiposity but not other anatomical measures of fat distribution eliminated the association between plasma 25(OH)D and insulin resistance., Conclusion: Central adiposity drives the association between plasma 25(OH)D and insulin resistance in overweight and obese adults. The trial was registered at clinicaltrials.gov as NCT00812409., (© 2015 American Society for Nutrition.)

Background: Studies assessing the effects of protein supplementation on changes in body composition (BC) and health rarely consider the impact of total protein intake (TPro) or the change in TPro (CTPro) from participants' usual diets., Objective: This secondary data analysis assessed the impact of TPro and CTPro on changes in BC and metabolic syndrome (MetS) indexes in overweight and obese middle-aged adults who participated in an exercise training program., Methods: Men and women [n = 117; age: 50 ± 0.7 y, body mass index (BMI; in kg/m(2)): 30.1 ± 0.3; means ± SEs] performed resistance exercise 2 d/wk and aerobic exercise 1 d/wk and consumed an unrestricted diet along with 200-kcal supplements (0, 10, 20, or 30 g whey protein) twice daily for 36 wk. Protein intake was assessed via 4-d food records. Multiple linear regression model and stratified analysis were applied for data analyses., Results: Among all subjects, TPro and CTPro were inversely associated (P < 0.05) with changes in body mass, fat mass (FM), and BMI. Changes in BC were different (P < 0.05) among groups that consumed <1.0 (n = 43) vs. ≥1.0 to <1.2 (n = 29) vs. ≥1.2 g · kg(-1) · d(-1) (n = 45). The TPro group with ≥1.0 to <1.2 g ·: kg(-1) ·: d(-1) reduced FM and %FM and increased percentage of LM (%LM) compared with the lowest TPro group, whereas the TPro group with ≥1.2 g ·: kg(-1) ·: d(-1) presented intermediate responses on changes in FM, %FM, and %LM. The gain in LM was not different among groups. In addition, MetS indexes were not influenced by TPro and CTPro., Conclusions: In conjunction with exercise training, higher TPro promoted positive changes in BC but not in MetS indexes in overweight and obese middle-aged adults. Changes in TPro from before to during the intervention also influenced BC responses and should be considered in future research when different TPro is achieved via diet or supplements. This trial was registered at clinicaltrials.gov as NCT00812409., (© 2015 American Society for Nutrition.)

Background: Hypertension is a major, modifiable risk factor for cardiovascular and kidney disease and premature mortality that is improved by the DASH (Dietary Approaches to Stop Hypertension) diet. The DASH diet emphasizes increased consumption of fruit and vegetables, whole grains, low-fat dairy, nuts, and poultry and fish and reduced intakes of fats, red meats (including pork), sodium, and added sugars., Objective: We sought to evaluate whether the consumption of lean pork compared with the consumption of chicken and fish as the predominant protein source in a DASH-style diet affected blood pressure (BP) control in men and women with elevated BP., Design: In a randomized crossover study, 13 women and 6 men [mean ± SEM age: 61 ± 2 y; BMI (in kg/m²): 31.2 ± 1.4] with elevated BP [systolic blood pressure (SBP)/diastolic blood pressure (DBP): 130 ± 2/85 ± 2 mm Hg] consumed a DASH-style diet for two 6-wk controlled dietary interventions (with a 4-wk diet washout between interventions) with either lean pork [DASH diet with pork (DASH-P)] or chicken and fish [DASH diet with chicken and fish (DASH-CF), the control diet] as the major protein source (55% of total protein intake). SBP and DBP were measured manually and with a 24-h BP monitoring system on 3 d before and 3 d at the end of each diet intervention., Results: Preintervention manual BP (DASH-P: 130/84 ± 2/1 mm Hg; DASH-CF: 129/84 ± 2/1 mg Hg) and postintervention manual BP (DASH-P: 122/79 ± 2/1 mm Hg; DASH-CF: 123/78 ± 3/1) were not different between the DASH-P and DASH-CF. Consumption of these DASH-style diets for 6 wk reduced all measures of BP (P < 0.05) with no differences in responses between the DASH-CF and DASH-P., Conclusion: The results indicate that adults with elevated BP may effectively incorporate lean pork into a DASH-style diet for BP reduction., (© 2015 American Society for Nutrition.)

Background: Dietary lipids are one of the most effective stimulators of carotenoid absorption, but very limited data exist on the impact of endogenous food sources of lipids to enhance carotenoid absorption. The co-consumption of whole egg with carotenoid-rich foods may increase overall carotenoid absorption via lipid-rich egg yolk., Objective: We designed this study to assess the effects of egg consumption on carotenoid absorption from a carotenoid-rich, raw mixed-vegetable salad., Design: Healthy young men (n = 16) consumed the same salad (all served with 3 g canola oil) with no egg (control), 75 g scrambled whole eggs (1.5 eggs) [low egg (LE)], and 150 g scrambled whole eggs (3 eggs) [high egg (HE)] (a randomized crossover design). Control, LE, and HE meals contained 23 mg, 23.4 mg (0.4 mg from eggs), and 23.8 mg (0.8 mg from eggs) total carotenoids and 3 g, 10.5 g (7.5 g from eggs), and 18 g (15 g from eggs) total lipids, respectively. Blood was collected hourly for 10 h, and the triacylglycerol-rich lipoprotein (TRL) fraction was isolated. Total and individual carotenoid contents, including lutein, zeaxanthin , α-carotene, β-carotene, and lycopene in TRL were analyzed, and composite areas under the curve (AUCs) were calculated., Results: The total mean (±SE) carotenoid AUC0-10h in TRL was higher for the HE meal than for LE and control meals [125.7 ± 19.4(a) compared with 44.8 ± 9.2(b) compared with 14.9 ± 5.2(b) nmol/L · 10 h, respectively (values without a common superscript letter differ); P < 0.0001]. The TRL AUC(0-10h) of lutein and zeaxanthin increased 4-5-fold (P < 0.001), and the TRL AUC(0-10h) of carotenoid not present in eggs, including α-carotene, β-carotene, and lycopene, increased 3-8-fold (P < 0.01) for the HE meal compared with the control meal., Conclusion: These findings support the claim that co-consuming cooked whole eggs is an effective way to enhance carotenoid absorption from other carotenoid-rich foods such as a raw mixed-vegetable salad. This trial was registered at clinicaltrials.gov as NCT01951313., (© 2015 American Society for Nutrition.)

Our understanding of the potential benefits and challenges of optimizing dietary protein intake in older adults continues to evolve. An overarching hypothesis generated during Protein Summit 2.0 was that consuming an adequate amount of high-quality protein at each meal, in combination with physical activity, may delay the onset of sarcopenia, slow its progression, reduce the magnitude of its functional consequences, or all of these. The potential benefits of young and middle-aged adults adopting a diet pattern whereby adequate protein is consumed at each meal as a countermeasure to sarcopenia are presented and discussed. For example, meeting a protein threshold (∼25-30 g/meal) represents a promising, yet still largely unexplored dietary strategy to help maintain muscle mass and function. For many older adults, breakfast is a carbohydrate-dominated lower-protein meal and represents an opportunity to improve and more evenly distribute daily protein intake. Although both animal and plant-based proteins can provide the required essential amino acids for health, animal proteins generally have a higher proportion of the amino acid leucine. Leucine plays a key role in stimulating translation initiation and muscle protein anabolism and is the focus of ongoing research. Protein requirements should be assessed in the light of habitual physical activity. An evenly distributed protein diet provides a framework that allows older adults to benefit from the synergistic anabolic effect of protein and physical activity. To fully understand the role of dietary protein intake in healthy aging, greater efforts are needed to coordinate and integrate research design and data acquisition and interpretation from a variety of disciplines., (© 2015 American Society for Nutrition.)

Background: The current estimated average requirement (EAR) and RDA for protein of 0.66 and 0.8 g ⋅ kg-1 ⋅ d-1, respectively, for adults, including older men, are based on nitrogen balance data analyzed by monolinear regression. Recent studies in young men and older women that used the indicator amino acid oxidation (IAAO) technique suggest that those values may be too low. This observation is supported by 2-phase linear crossover analysis of the nitrogen balance data., Objective: The main objective of this study was to determine the protein requirement for older men by using the IAAO technique., Methods: Six men aged >65 y were studied; each individual was tested 7 times with protein intakes ranging from 0.2 to 2.0 g ⋅ kg-1 ⋅ d-1 in random order for a total of 42 studies. The diets provided energy at 1.5 times the resting energy expenditure and were isocaloric. Protein was consumed hourly for 8 h as an amino acid mixture with the composition of egg protein with L-[1-13C]phenylalanine as the indicator amino acid. The group mean protein requirement was determined by applying a mixed-effects change-point regression analysis to F13CO2 (label tracer oxidation in breath 13CO2), which identified a breakpoint in F13CO2 in response to graded intakes of protein., Results: The estimated protein requirement and RDA for older men were 0.94 and 1.24 g ⋅ kg-1 ⋅ d-1, respectively, which are not different from values we published using the same method in young men and older women., Conclusions: The current intake recommendations for older adults for dietary protein of 0.66 g ⋅ kg-1 ⋅ d-1 for the EAR and 0.8 g ⋅ kg-1 ⋅ d-1 for the RDA appear to be underestimated by ∼30%. Future longer-term studies should be conducted to validate these results. This trial was registered at clinicaltrials.gov as NCT01948492., (© 2016 American Society for Nutrition.)

Background: Studies on protein requirements in vulnerable groups such as older adults are few, and results are conflicting., Objective: The main objective of this study was to determine the protein requirements of free-living women >65 y by measuring the oxidation of l-[1-(13)C]phenylalanine to (13)CO2 in response to graded intakes of protein., Methods: Twelve subjects participated in the study, with protein intakes ranging from 0.2 to 2.0 g · kg(-1) · d(-1) for a total of 82 studies. The diets provided energy at 1.5 times each subject's resting energy expenditure and were isocaloric. Protein was given as an amino acid mixture on the basis of the egg protein pattern, except for phenylalanine and tyrosine, which were maintained constant across the protein intake amounts. All subjects were adapted for 2 d before the study day to a protein intake of 1.0 g · kg(-1) · d(-1). The mean protein requirement was determined by applying a mixed-effects change-point regression analysis to F(13)CO2 (label tracer oxidation in (13)CO2 breath), which identified a breakpoint in the F(13)CO2 in response to graded amounts of protein., Results: The mean estimated average requirement (EAR) and upper 95% CI (approximating the RDA) protein requirement of women >65 y were 0.96 and 1.29 g · kg(-1) · d(-1), respectively., Conclusion: These estimates of protein requirements for older women are higher than the current EAR and RDA based on nitrogen balance data, which are 0.66 and 0.80 g · kg(-1) · d(-1), respectively. This trial was registered at clinicaltrials.gov as NCT01604980., (© 2015 American Society for Nutrition.)

Background: Disrupting the physical structure of pulses by blending them or by using a digestive supplement (α-galactosidase) to reduce intestinal discomfort could potentially negate the previously observed beneficial effects of whole pulses of lowering appetitive and glycemic responses because of more rapid digestion., Objective: We hypothesized that blended lentils, α-galactosidase, or both increase postprandial appetite and blood glucose responses vs. whole lentils., Methods: Men and women [n = 12; means ± SDs body mass index (kg/m(2)): 23.3 ± 3.1; aged 28 ± 10 y] consumed breakfast meals containing whole (W), blended (B), or no lentils [control (C)], each with 3 α-galactosidase or placebo capsules in a randomized, crossover, double-blind placebo-controlled trial. Between each test day there was a 3- to 5-d washout period., Results: Mixed-model ANOVA showed effects of meal on postprandial appetite and glucose (P = 0.0001-0.031). The B meal resulted in higher postprandial appetite ratings than did the W meal but not the C meal for hunger, desire to eat, and prospective consumption (Δ = 0.4-0.5 points; P = 0.002-0.044). Postprandial glucose concentration was 4.5 mg/dL lower for the B meal than for the C meal (P < 0.0001) but did not differ from the W meal. There were no main effects of α-galactosidase, but there were meal × α-galactosidase interaction effects, with a greater postprandial desire to eat and lower postprandial fullness with the B meal than with the 2 other meals in the placebo condition but not in the α-galactosidase condition., Conclusions: Blending lentils increased appetite (∼6%), but not glycemic response, compared with whole lentils, whereas α-galactosidase did not. Both B and W meals may be consumed (with or without an α-galactosidase supplement) with little impact on appetite, without increasing glycemic response. This trial was registered at clinicaltrials.gov as NCT02110511., (© 2014 American Society for Nutrition.)

Background: Data on the protein requirements of elderly adults are limited, because it is impractical to conduct repeated nitrogen balance protocols in these vulnerable humans., Objective: This study was designed to determine the dietary protein requirement of elderly women by using the recently developed minimally invasive indicator amino acid oxidation (IAAO) technique., Design: Six white women aged 80-87 y [mean ± SEM: 82 ± 1 y and body mass index (in kg/m²) 26 ± 2] completed a 3-d protocol 7 times. Each woman consumed an adaptation diet for 2 d and on day 3 consumed a complete test diet with a crystalline amino acid mixture containing 1 of 7 protein intakes (0.1, 0.3, 0.6, 0.9, 1.2, 1.5, or 1.8 g · kg⁻¹ · d⁻¹) tested randomly. A group-based protein requirement was assessed by using a nonlinear mixed model of protein intake and L-[1-¹³C]phenylalanine oxidation. The breakpoint, at which there was no further decline in the rate of appearance of ¹³C in the breath, was used as an index of the mean protein requirement., Results: The mean protein requirement (95% CI) was 0.85 (0.60, 1.09) g · kg⁻¹ · d⁻¹. This requirement is 29% higher than the current Estimated Average Requirement (EAR) for adults of 0.66 g · kg⁻¹ · d⁻¹ based on the nitrogen balance technique, although the 95% CI includes the current EAR. The corresponding adequate protein allowance of 1.15 (0.77, 1.54) g · kg⁻¹ · d⁻¹ is 44% higher, although the 95% CI includes the Recommended Dietary Allowance (RDA) of 0.80 g · kg⁻¹ · d⁻¹., Conclusions: Notwithstanding uncertainty about the validity of the use of the IAAO technique to assess protein requirements, the results of this study with octogenarian women suggest that the current EAR and RDA for elderly women may be underestimated. The limitations of this short-term, noninvasive method underscore the need for new research that uses alternative experimental designs and measuring physiologic, morphologic, and health-related outcomes.

High-protein (>30% of energy from protein or >1.2 g/kg/day) and moderately high-protein (22% to 29% of energy from protein or 1.0 to 1.2 g/kg/day) diets are popular for weight loss, but the effect of dietary protein on bone during weight loss is not well understood. Protein may help preserve bone mass during weight loss by stimulating insulin-like growth factor 1, a potent bone anabolism stimulator, and increasing intestinal calcium absorption. Protein-induced acidity is considered to have minimal effect on bone resorption in adults with normal kidney function. Both the quantity and predominant source of protein influence changes in bone with diet-induced weight loss. Higher-protein, high-dairy diets may help attenuate bone loss during weight loss., (Copyright © 2014 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.)

Little is known about the effects of different quantities of whey protein on exercise training-induced changes in body composition and indices of metabolic syndrome in middle-aged overweight and obese adults. Therefore, we examined the effects of consuming 0.8-MJ supplements with 0 (n = 126), 10 (n = 112), 20 (n = 44), or 30 (n = 45) g whey protein twice daily in conjunction with resistance (2 d/wk) and aerobic (1 d/wk) exercise training in a double-blind, randomized, placebo-controlled, community-based 9-mo study in men (n = 117) and women (n = 210); (age: 48 ± 7.9 y; BMI: 30.0 ± 2.8 kg/m(2)). Whey protein supplementation did not influence any of the following outcomes, some of which were affected by training. Among all participants, strength increased by 15 ± 12% (P < 0.001) and maximal oxygen uptake capacity (VO(2)max) increased by 9 ± 15% (P < 0.001). Body weight was unchanged (0.1 ± 3.7 kg, P = 0.80), lean body mass increased by 1.9 ± 2.8% (0.95 ± 1.3 kg, P < 0.001), and fat mass decreased by 2.6 ± 9.4% (-0.86 ± 3.1 kg, P = 0.001). Oral-glucose-tolerance testing showed that plasma glucose AUC was unchanged (-18.0 ± 170 mmol/L·  3 h, P = 0.16), insulin AUC decreased by 2.6 ± 32% (-7.5 ± 29 nmol/L·  3 h, P = 0.01), and HOMA-IR (0.2 ± 2.0, P = 0.81) and the insulin sensitivity index (0.3 ± 3.0, P = 0.63) were unchanged. Plasma concentrations of TG; total, LDL, and HDL cholesterol; C-reactive protein; plasminogen activator inhibitor-1; blood pressure; and waist circumference were unchanged. Whey protein supplementation did not affect exercise training-induced responses in body composition and indices of metabolic syndrome in middle-aged overweight and obese adults who maintained body weight.

Background: Dairy product and calcium consumption have been associated with modifying body fat and body weight in children and adults., Objective: In overweight adolescent boys and girls, we aimed to determine the effect of the doubling of habitual calcium intake to the recommended intake from dairy or calcium carbonate on energy balance and purported mechanisms including fecal fat excretion, macronutrient use, and parathyroid hormone suppression., Design: Twenty-five girls with a mean (±SD) BMI (in kg/m(2)) of 33 ± 5 and 17 boys with a BMI of 28 ± 5, aged 12-15 y, participated in two 3-wk controlled feeding sessions that used a crossover design in random order as a summer research camp. In one session, 756 mg Ca/d was consumed; in the other session, an additional 650 mg Ca/d was provided as dairy or calcium carbonate supplements that were matched to the control in macronutrient content. Total energy and macronutrient intakes were controlled and were the same for the 2 sessions for each subject. Primary outcome measures were energy balance, fecal fat excretion, lipid oxidation, and postprandial energy expenditure., Results: There were no effects of quantity or source of calcium on energy or fat balance, despite calcium-induced increases (P <0.01) in postprandial serum parathyroid hormone suppression., Conclusion: These data lend little evidence to support the proposed mechanisms for the relation between an increase in calcium intake from calcium carbonate or dairy and weight loss or weight maintenance in children. This trial was registered at clinicaltrials.gov as NCT00592137.

The ASN hosted a symposium entitled "Eating Patterns and Energy Balance: A Look at Eating Frequency, Snacking, and Breakfast Omission" at the Experimental Biology 2009 annual meeting on April 19, 2009, in New Orleans, LA. The symposium was chaired by Megan McCrory and co-chaired by Wayne Campbell, both from Purdue University. The goal of the symposium was to bring together experts to provide an overview of research on the potential role of eating patterns in the development of overweight and obesity. Studies on eating frequency, snacking, and breakfast skipping were highlighted. In particular, evidence both for and against their roles were discussed, methodological issues that underlie controversies were addressed, and suggested future directions for research were outlined. Appetite regulation and hormonal effects were also reviewed. Megan McCrory introduced the session then discussed studies on eating frequency and energy regulation in free-living adults consuming self-selected diets. Heather Leidy summarized the state of the research on eating frequency and energy regulation in adults from controlled feedings studies. Didier Chapelot discussed various usages of "snack" and argued for a physiological basis to distinguish snacks from meals. Mark Pereira presented information on the effects of breakfast skipping and the macronutrient composition of breakfast in energy regulation and mood. A panel discussion/question and answer session ended the symposium. The symposium was videotaped and can be viewed at www.nutrition.org.

Increased eating frequency is postulated to increase metabolism, reduce hunger, improve glucose and insulin control, and reduce body weight, making it an enticing dietary strategy for weight loss and/or the maintenance of a healthy body weight. Because past research has primarily focused on the effects of eating frequency on changes in energy expenditure and body weight, limited data exist surrounding the impact of eating frequency on appetite control and energy intake. We provide a brief review of the controlled-feeding studies that primarily targeted the appetitive, hormonal, and food intake responses potentially altered with eating frequency. The 3 meal/d pattern served as the reference for defining increased or reduced eating frequency. In general, increased eating frequency led to lower peaks (P < 0.05) in perceived appetite, satiety, glucose, insulin, ghrelin, and PYY responses compared with reduced eating frequency. However, when examining these responses over the course of the day (i.e. using area under the curve assessments), no differences in any of these outcomes were observed. The rate of gastric emptying also appears to be unaltered with increased eating frequency. Subsequent food intake was examined in several studies with conflicting results. Regarding the effect of reduced eating frequency, several studies indicate significant increases in perceived appetite and reductions in perceived satiety when 1 or 2 meals were eliminated from the daily diet. Taken together, these findings suggest that increased eating frequency (>3 eating occasions/d) has minimal, if any, impact on appetite control and food intake, whereas reduced eating frequency(<3 eating occasions/d) negatively effects appetite control.

Background: The accuracy of dietary energy assessment tools is critical to understanding the role of diet in the increasing rate of obesity., Objectives: The purposes of our study in overweight adolescent boys and girls were 1) to assess the energy reporting bias of diet records against the referent of total energy expenditure (TEE) and 2) to compare the methods of determining energy needs by using measured metabolizable energy intake (MEI) and TEE., Design: Twenty girls [12-15 y, body mass index (in kg/m2) = 33.0 +/- 5] and 14 boys (12-14 y, body mass index = 27.4 +/- 4) participated in 2- to 3-wk metabolic balance studies. TEE was measured by using doubly labeled water (TEE(DLW)), and MEI was measured by bomb calorimetry of composite daily diet, urine, and fecal collections. Food records were collected before each study., Results: Food records underreported TEE(DLW) by 35 +/- 20%. Underreporting of energy intake was correlated with all macronutrient intake concentrations (g or kcal) (P < 0.0001). A multiple regression model showed that 86.4% of the variance in underreporting error was explained by dietary fat (g), BMI, and sex. The intrasubject CV was 3.9% for TEE(DLW) and 9.9% for MEI. MEI for weight stability (MEI(wtstb)) averaged 99 +/- 11% of TEE., Conclusions: The increased underreporting of dietary intake with increasing body weight in teens may explain in part previous reports noting that there has been an increased incidence of obesity, although energy intakes have not appeared to increase. MEI(wtstb) and TEE(DLW) gave similar estimates of energy needs. This trial was registered at clinicaltrials.gov as NCT 00592137.

Objective: Overweight and obesity have been attributed to increased eating frequency and the size of eating events. This study explored the influence of the timing of eating events and food form on appetite and daily energy intake., Design: Crossover, clinical intervention where participants consumed 300-kcal loads of a solid (apple), semisolid (apple sauce), and beverage (apple juice) at a meal or 2 hours later (snack)., Subjects: Twenty normal-weight (body mass index 22.6+/-1.8) and 20 obese (body mass index 32.3+/-1.5) adults. There were 10 men and 10 women within each body mass index group., Measurements: On six occasions, participants reported to the laboratory at their customary midday mealtime. Appetite questionnaires and motor skills tests were completed upon arrival and at 30-minute intervals for the 2 hours participants were in the laboratory and at 30-minute intervals for 4 hours after leaving the laboratory. Diet recalls were collected the next day. Data were collected between January 2006 and March 2007., Results: Whether consumed with a meal or alone as a snack, the beverage elicited the weakest appetitive response, the solid food form elicited the strongest appetitive response and the semisolid response was intermediate. The appetite shift was greatest for the solid food when consumed as a snack. The interval between test food consumption and the first spontaneous eating event >100 kcal was shortest for the beverage. No significant treatment effects were observed for test day energy intake or between lean individuals and individuals with obesity., Conclusions: Based on the appetitive findings, consumption of an energy-yielding beverage either with a meal or as a snack poses a greater risk for promoting positive energy than macronutrient-matched semisolid or solid foods consumed at these times.

Background: For older men and women, the Estimated Average Requirement (EAR) and Recommended Dietary Allowance (RDA) for protein are not known with confidence. Data from the limited research studies available suggest that the EAR and RDA might be greater than the assumed 0.66 and 0.80 g protein x kg body wt(-1) x d(-1), respectively., Objective: This study assessed the effect of age on the EAR and RDA for protein., Design: Twenty-three younger (age: 21-46 y; 11 men, 12 women) and 19 older (age: 63-81 y; 8 men, 11 women) persons completed three 18-d trials with protein intakes of 0.50, 0.75, and 1.00 g protein x kg body wt(-1) x d(-1). Nitrogen balance was determined by using data from total nitrogen analyses of duplicate food composites and complete urine and feces collections from days 14 to 17 of each trial. Each subject's protein requirement was estimated by using linear regression of protein intake and nitrogen balance data from all 3 trials and inverse prediction., Results: The mean (+/- SD) protein requirement was not different between the younger and older subjects: 0.61 +/- 0.14 compared with 0.58 +/- 0.12 g protein x kg body wt(-1) . d(-1). On the basis of individual requirement estimates from the younger and older subjects combined (2.5% trimming from each tail and variation estimated by the bootstrap), an adequate protein allowance for these subjects was calculated to be 0.85 +/- 0.21 g protein x kg body wt(-1) x d(-1)., Conclusions: These short-term nitrogen balance results suggest that the requirement for total dietary protein is not different for healthy older adults than for younger adults and that the allowance estimate does not differ statistically from the RDA.

Objective: This controlled feeding study examined the effects of exercise on daily water intake (particularly ad libitum water intake), water output, whole-body water balance, and hydration status in physically active, premenopausal women., Design: The randomized crossover design consisted of three 8-day trials: placebo and no exercise, placebo and exercise (1-hour cycling bout per day at 65%-70% of heart rate reserve), and 800 mg calcium supplementation and exercise. During each trial, controlled quantities of the same foods and beverages were provided and ad libitum water intake was quantified. Water input included measured water from foods and beverages, measured ad libitum intake, and estimated metabolic production. Water output included measured losses in urine and stool, and estimated insensible losses from respiration and non-sweating perspiration (insensible diffusion through the skin)., Subjects: Participants were 26 women, age 25+/-5 years, body mass index 22+/-2, and VO(2peak) 43+/-6 mLxkg(-1)xmin(-1) (mean+/-standard deviation)., Results: Ad libitum water intake was 363 g/day more (P<0.05) for the placebo and exercise (1,940+/-654 g/day) and calcium supplementation and exercise (1,935+/-668 g/day) trials, compared with placebo and no exercise trial (1,575+/-667 g/day), and total water input was correspondingly higher in placebo and exercise and calcium supplementation and exercise trials compared with the placebo and no exercise trial. Urine, stool, and total water outputs were not different among trials. Apparent net water balance (representative of sweat water output) was 367 g/day more (P<0.05) in placebo and exercise (679+/-427 g/day) and calcium supplementation and exercise (641+/-519 g/day) trials compared with placebo and no exercise trial (293+/-419 g/day). Hydration status was clinically normal during all three trials. Calcium supplementation did not influence water balance., Conclusion: These results support that young, physically active women can completely compensate for exercise-induced sweat losses by increasing ad libitum water intake, and not decreasing non-sweat water outputs or impairing hydration status.