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Objective: Diets with a low proportion of energy from protein have shown to cause overconsumption of non-protein energy, known as Protein Leverage. Older adults are susceptible to nutritional inadequacy. The aim was to investigate associations between protein to non-protein ratio (P:NP) and intakes of dietary components and assess the nutritional adequacy of individuals aged 65–75 years from the Nutrition for Healthy Living (NHL) Study. Design: Cross-sectional. Nutritional intakes from seven-day weighed food records were compared with the Nutrient Reference Values for Australia and New Zealand, Australian Guide to Healthy Eating, Australian Dietary Guidelines and World Health Organisation Free Sugar Guidelines. Associations between P:NP and intakes of dietary components were assessed through linear regression analyses. Setting: NHL Study. Participants: 113 participants. Results: Eighty-eight (59 female and 29 male) with plausible dietary data had a median (interquartile range) age of 69 years (67–71), high education level (86 %) and sources of income apart from the age pension (81 %). Substantial proportions had intakes below recommendations for dairy and alternatives (89 %), wholegrain (89 %) and simultaneously exceeded recommendations for discretionary foods (100 %) and saturated fat (92 %). In adjusted analyses, P:NP (per 1 % increment) was associated with lower intakes of energy, saturated fat, free sugar and discretionary foods and higher intakes of vitamin B12, Zn, meat and alternatives, red meat, poultry and wholegrain % (all P < 0·05). Conclusions: Higher P:NP was associated with lower intakes of energy, saturated fat, free sugar and discretionary. Our study revealed substantial nutritional inadequacy in this group of higher socio-economic individuals aged 65–75 years. [ABSTRACT FROM AUTHOR]

Aim: The aim was to assess two macronutrient interventions in a 2 × 2 factorial dietary design to determine their effects on oral health. Materials and Methods: Participants (65–75 years old) with a body mass index between 20 and 35 kg/m2 of a larger randomized control trial who consented to an oral health assessment were recruited. They had ad libitum access to one of four experimental diets (omnivorous higher fat or higher carbohydrate, semi‐vegetarian higher fat or higher carbohydrate) for 4 weeks. The periodontal examination included periodontal probing depth (PPD), clinical attachment level (CAL), and bleeding on probing. Oral plaque and gingival crevicular fluid (GCF) were collected before and after the intervention. Results: Between baseline and follow up, the number of sites with a CAL <5 mm (mean difference [MD] −5.11 ± 9.68, p =.039) increased and the GCF amount (MD −23.42 ± 39.42 Periotron Units [PU], p =.050) decreased for the semi‐vegetarian high‐fat diet. For the mean proportion of sites with PPD reduction of >1 mm and CAL gain of >1 mm, significant differences were calculated between the diets investigated. The clinical parameters were not associated with changes in the oral microbiota. Conclusions: The results of this study provided evidence that a semi‐vegetarian high‐fat diet provides benefits to clinical parameters of periodontal health. This study is registered in ClinicalTrials.gov (ACTRN12616001606471). [ABSTRACT FROM AUTHOR]

BACKGROUND: Worldwide, populations are ageing with significant impact on health patterns. Studies have shown that low protein, high carbohydrate diets are associated with more favourable outcomes. Plant-based diets have also been shown to have a positive impact on cardiometabolic health, weight loss and prevention of all causes of mortality. OBJECTIVE: The aim of the current study is to assess the main and interactive effects of two macronutrient interventions in a 2×2 factorial dietary design to determine their effects on appetite and health outcomes in older individuals. METHODS: Individuals aged 65 to 75 with a BMI between 20 and 35 kg/m2 were recruited. Participants were provided with ad libitum access to one of four diets for four weeks, designed as a 2×2 factorial. Each dietary treatment provided 14% of energy as protein, which was either omnivorous or semi-vegetarian in origin. The remaining complement of macronutrient energy (80–82%) was either relatively high in fat (37–41% of energy) and low in carbohydrates (41–43%), or vice versa (28–29% fat with 53% carbohydrate). Study diets were provided via a meal delivery company. Self-completed questionnaires, biospecimen and clinical assessments were collected before and after intervention to assess cardio-metabolic, oral and gut health, body composition and physical performance. RESULTS: Trial status is currently ongoing (sample and data analyses). CONCLUSIONS: This study will help determine whether protein-source (plant vs animal) and fat to carbohydrate ratio have an impact on predictors of healthy ageing. These findings will also create a sound foundation on which to base nutritional interventions in older individuals to support healthy ageing. [ABSTRACT FROM AUTHOR]

The revised Dietary Guideline Index (DGI-2013) scores individuals’ diets according to their compliance with the Australian Dietary Guideline (ADG). This cross-sectional study assesses the diet quality of 794 community-dwelling men aged 74 years and older, living in Sydney, Australia participating in the Concord Health and Ageing in Men Project; it also examines sociodemographic and lifestyle factors associated with DGI-2013 scores; it studies associations between DGI-2103 scores and the following measures: homoeostasis model assessment – insulin resistance, LDL-cholesterol, HDL-cholesterol, TAG, blood pressure, waist:hip ratio, BMI, number of co-morbidities and medications and frailty status while also accounting for the effect of ethnicity in these relationships. Median DGI-2013 score was 93·7 (54·4, 121·2); most individuals failed to meet recommendations for vegetables, dairy products and alternatives, added sugar, unsaturated fat and SFA, fluid and discretionary foods. Lower education, income, physical activity levels and smoking were associated with low scores. After adjustments for confounders, high DGI-2013 scores were associated with lower HDL-cholesterol, lower waist:hip ratios and lower probability of being frail. Proxies of good health (fewer co-morbidities and medications) were not associated with better compliance to the ADG. However, in participants with a Mediterranean background, low DGI-2013 scores were not generally associated with poorer health. Older men demonstrated poor diet quality as assessed by the DGI-2013, and the association between dietary guidelines and health measures and indices may be influenced by ethnic background. [ABSTRACT FROM PUBLISHER]

A dominant appetite for protein drives increased energy intake in humans when the proportion of protein in the diet is reduced down to approximately 10% of total energy. Compensatory feeding for protein is apparent over a 1–2 d period but the mechanisms driving this regulation are not fully understood. Fibroblast growth factor-21 (FGF-21) has been identified as a candidate protein signal as levels increase in the circulation when dietary protein is low. The aim of this randomised controlled trial was to assess whether changes in percent dietary protein over a 4 d ad libitum experimental period in lean, healthy participants influenced energy intake, metabolic health, circulating FGF-21 and appetite regulating hormones including ghrelin, glucagon like peptide-1 and cholecystokinin. Twenty-two lean, healthy participants were fed ad libitum diets containing 10, 15 and 25% protein, over three, 4 d controlled, in-house experimental periods. Reduced dietary protein intake from 25% to 10% over a period of 4 d was associated with 14% increased energy intake (p = 0.02) as previously reported, and a 6-fold increase in fasting circulating plasma FGF-21 levels (p<0.0001), a 1.5-fold increase in serum triglycerides (p<0.0001), and a 0.9-fold decrease in serum total cholesterol (p = 0.02). Serum HDL cholesterol was reduced with a reduction in dietary protein from 15% to 10% (p = 0.01) over 4 d but not from 25% to 10% (p = 0.1) and the change from baseline was not different between diets. Plasma fasting insulin levels following the 4 d study period were significantly lower following the 25% ad libitum study period compared to the 15% protein period (p = 0.014) but not the 10% protein period (p = 0.2). Variability in interstitial glucose during each study period increased with a decrease in dietary protein from 25% to 15% and 10% (p = 0.001 and p = 0.04, respectively). Ghrelin, glucagon-like peptide-1 and cholecystokinin were unchanged. Increases in energy intake, plasma FGF-21 and serum triglycerides were associated with reductions in percent dietary protein from 25% to 10% energy over a 4 d ad libitum in-house feeding period and may be important in regulation of dietary protein intake. Trial Registration: Australia New Zealand Clinical Trials Registry [ABSTRACT FROM AUTHOR]

Objective: Protein leverage plays a role in driving increased energy intakes that may promote weight gain. The influence of the protein to carbohydrate ratio (P:C) in diets of C57BL/6J mice on total energy intake, fat storage, and thermogenesis was investigated. Design and Methods: Male mice (9 weeks old) were provided ad libitum access to one of five isocaloric diets that differed in P:C. Food intake was recorded for 12 weeks. After 16 weeks, white adipose tissue (WAT) and brown adipose tissue (BAT) deposits were dissected, weighed, and the expression levels of key metabolic regulators were determined in BAT. In a separate cohort, body surface temperature was measured in response to 25 diets differing in protein, fat, and carbohydrate content. Results: Mice on low P:C diets (9:72 and 17:64) had greater total energy intake and increased WAT and BAT stores. Body surface temperature increased with total energy intake and with protein, fat, and carbohydrate, making similar contributions per kJ ingested. Expression of three key regulators of thermogenesis were downregulated in BAT in mice on the lowest P:C diet. Conclusions: Low-protein diets induced sustained hyperphagia and a generalized expansion of fat stores. Increased body surface temperature on low P:C diets was consistent with diet-induced thermogenesis (DIT) as a means to dissipate excess ingested energy on such diets, although this was not sufficient to prevent development of increased adiposity. Whether BAT was involved in DIT is not clear. Increased BAT mass on low P:C diets might suggest so, but patterns of thermogenic gene expression do not support a role for BAT in DIT, although they might reflect failure of thermogenic function with prolonged exposure to a low P:C diet. [ABSTRACT FROM AUTHOR]

A significant contributor to the rising rates of human obesity is an increase in energy intake. The 'protein leverage hypothesis' proposes that a dominant appetite for protein in conjunction with a decline in the ratio of protein to fat and carbohydrate in the diet drives excess energy intake and could therefore promote the development of obesity. Our aim was to test the 'protein leverage hypothesis' in lean humans by disguising the macronutrient composition of foods offered to subjects under ad libitum feeding conditions. Energy intakes and hunger ratings were measured for 22 lean subjects studied over three 4-day periods of in-house dietary manipulation. Subjects were restricted to fixed menus in random order comprising 28 foods designed to be similar in palatability, availability, variety and sensory quality and providing 10%, 15% or 25% energy as protein. Nutrient and energy intake was calculated as the product of the amount of each food eaten and its composition. Lowering the percent protein of the diet from 15% to 10% resulted in higher (+12±4.5%, p = 0.02) total energy intake, predominantly from savoury-flavoured foods available between meals. This increased energy intake was not sufficient to maintain protein intake constant, indicating that protein leverage is incomplete. Urinary urea on the 10% and 15% protein diets did not differ statistically, nor did they differ from habitual values prior to the study. In contrast, increasing protein from 15% to 25% did not alter energy intake. On the fourth day of the trial, however, there was a greater increase in the hunger score between 1-2 h after the 10% protein breakfast versus the 25% protein breakfast (1.6±0.4 vs 25%: 0.5±0.3, p = 0.005). In our study population a change in the nutritional environment that dilutes dietary protein with carbohydrate and fat promotes overconsumption, enhancing the risk for potential weight gain. [ABSTRACT FROM AUTHOR]

Abstract: Our aim was to design a selection of foods with differing proportions of protein but equal palatability in two settings, Sydney Australia and Kingston Jamaica. The foods were manipulated to contain 10, 15 or 25% E as protein with reciprocal changes in carbohydrate to 60, 55 or 45% E and dietary fat was kept constant at 30%. Naïve participants did not identify a difference in protein between the versions. On average, the versions were rated equal in pleasantness (Sydney-10%: 44±2, 15%: 49±2 and 25%: 49±2 Kingston-10%: 41±3, 15%: 41±3 and 25%: 37±3). [Copyright &y& Elsevier]

This study tests the hypothesis that a high-fat postnatal diet increases fat mass and reduces improved insulin sensitivity (IS) found in the low-protein model of maternal undernutrition. Offspring from Wistar dams fed either a 20% (control (CON)) or 8% (low protein (LP)) protein diet during gestation and lactation were randomly assigned to a control (con) or cafeteria (caf) diet at weaning (21 days) until 3 months of age at which point IS was measured (hyperinsulinemic–euglycemic clamp). Fat mass, growth, energy intake (EI) and expenditure (EE), fuel utilization, insulin secretion, and leptin and adiponectin levels were measured to identify a possible role in any changes in IS. IS was increased in LP-con in comparison to CON-con animals. Cafeteria feeding prevented this increase in LP animals but had no effect in CON animals (insulin-stimulated glucose infusion rates (GIRs; mg/min/kg); CON-con: 13.9 ± 1.0, CON caf: 12.1 ± 2.1, LP-con: 25.4 ± 2.0, LP-caf: 13.7 ± 3.7, P < 0.05). CON-caf animals had similar percent epididymal white adipose tissue (%EWAT; CON-con: 1.71 ± 0.09 vs. CON-caf: 1.66 ± 0.08) and adiponectin (µg/ml: CON-con: 4.61 ± 0.34 vs. CON-caf: 3.67 ± 0.18) except hyperinsulinemia and relative hyperleptinemia in comparison to CON-con. Differently, LP-caf animals had increased %EWAT (LP-con: 1.11 ± 0.06 vs. LP-caf: 1.44 ± 0.08, P < 0.05) and adiponectin (µg/ml: LP-con: 5.38 ± 0.39 vs. LP-caf: 3.75 ± 0.35, P < 0.05) but did not show cafeteria-induced hyperinsulinemia or relative hyperleptinemia. An increased propensity to store visceral fat in LP animals may prevent the elevated IS in LP offspring. [ABSTRACT FROM AUTHOR]

The insulin-like growth factor (IGF) system is altered with intra-uterine growth retardation and in adult metabolic disease. The aim of the present study was to observe effects of continued protein restriction on the IGF-I system and body composition in offspring of mothers fed a low-protein (LP) diet. Offspring from Wistar dams fed either a 20 % (CON) or 8 % (LP) protein diet during gestation and lactation were studied at birth, 10 d, weaning and at 12 weeks after maintenance on either the 8 % (lp) or 20 % (con) protein diet from weaning. LP offspring had reduced weaning weights (P < 0·05) and reduced serum insulin (P < 0·005). Serum IGF-I (P < 0·001) and acid-labile subunit (ALS) (P < 0·0001) were reduced at 10 and 21 d. Hepatic expression of IGF-I (P < 0·05) and ALS (P < 0·005) were reduced at 10 and 21 d. IGF binding protein (IGFBP)-1 hepatic expression was elevated at 10 d (P < 0·001) but not at 21 d. Adult LP-con offspring had reduced body weight (P < 0·05), lean (P < 0·0001) and bone (P < 0·0001) but not fat (P = 0·6) mass with no persistent effects on IGF-I, ALS and IGFBP-1.Postnatal lp feeding reduced lean mass (P < 0·0001) and bone mass (P < 0·0001) in CON and LP animals. Percentage fat (LP P = 0·04; CON P = 0·6) and IGFBP-1 (LP P = 0·01; CON P = 0·2) were increased in LP-lp but not CON-lp offspring. This suggests that postnatal nutrition is important in the effects of maternal protein restriction on adult body composition and that IGFBP-1 may be involved. [ABSTRACT FROM PUBLISHER]