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Energy intake is the product of portion size (PS)-the energy content of an ingestive event-and ingestive frequency (IF)-the number of ingestive events per unit time. An uncompensated alteration in either PS or IF would result in a change in energy intake and body weight if maintained over time. The objective of this meta-analysis was to assess the independent effects of PS and IF on energy intake and body weight among healthy adults in randomized controlled trials (RCTs). A total of 9708 articles were identified in PubMed, Web of Science, Cochrane, and CINAHL databases. The articles were divided among 10 researchers; each article was screened for eligibility by 2-3 independent reviewers. Exclusion criteria included: populations <19 y and >65 y, unhealthy populations (i.e. participants with an acute or chronic disease), assessments <24 h and <4 wk in duration for trials investigating energy intake or body weight, respectively. Controlled feeding trials (i.e. fixed energy intake) that manipulated IF and PS in the same study intervention (IF/PS) were evaluated separately and for the body weight outcome only. Twenty-two studies (IF = 4, PS = 14, IF/PS = 4) met the inclusion criteria. There was an insufficient number of studies to assess the effect of IF, PS, or IF/PS on body weight. There was heterogeneity in the effect sizes among all comparisons (I2 ≥75%). Consuming larger portion sizes was associated with higher daily energy intake [295 kcal (202, 388), n = 24; weighted mean differences (WMD) (95% CI), n = comparisons], and increased frequency of ingestive events was associated with higher energy intake [203 kcal (76, 330), n = 10]. Results from RCTs support that larger PS and greater IF are both associated with higher energy consumption. However, there is insufficient information to determine chronic effects on body weight. This protocol was registered at the International Prospective Register of Systematic Reviews (PROSPERO) as CRD42018104757., (© The Author(s) 2021. Published by Oxford University Press on behalf of the American Society for Nutrition.)

The post-lunch dip in cognition is a well-established phenomenon of decreased alertness, memory and vigilance after lunch consumption. Lunch composition reportedly influences the post-lunch dip. Moreover, dieting is associated with cognitive function impairments. The negative effects of dieting have been reversed with nut-supplemented diets. The aims of this study were to (1) evaluate the acute effect of an almond-enriched high-fat lunch or high-carbohydrate lunch on the post-lunch decline in cognitive function, and (2) evaluate the effects of chronic almond consumption as part of an energy-restricted diet on the memory and attention domains of cognitive function. In total, eighty-six overweight and obese adults were randomised to consume either an almond-enriched diet (AED) or a nut-free control diet (NFD) over a 12-week weight loss intervention. Participants were also randomised to receive either an almond-enriched high-fat lunch (A-HFL) (>55 % energy from fat, almonds contributing 70-75 % energy) or a high-carbohydrate lunch (HCL) (>85 % energy from carbohydrates) at the beginning and end of the weight loss intervention. Memory and attention performance indices decreased after lunch consumption (P<0·001). The A-HFL group ameliorated the decline in memory scores by 57·7 % compared with the HCL group (P=0·004). Both lunch groups had similar declines in attention. Moreover, memory and attention performance indices increased after the 12-week intervention period (P<0·05) with no difference between the AED and NFD groups. In conclusion, almond consumption at a midday meal can reduce the post-lunch dip in memory. However, long-term almond consumption may not further improve cognitive function outcomes in a weight loss intervention.

Controlling hunger between meals is a challenge for many individuals. This manuscript comprises 2 sequential clinical trials investigating the effects of psyllium (Metamucil) on satiety, both using a randomized, double-blind, placebo-controlled cross-over design. The first study determined the effects of 3.4 g, 6.8 g, and 10.2 g of psyllium taken before breakfast and lunch for 3 days. The second study determined the effects of 6.8 g (taken before breakfast and lunch on Days 1 and 2 and before breakfast on Day 3) on the satiety of participants receiving an energy restricted meal in the morning (breakfast) for 3 days. Efficacy endpoints were mean inter-meal hunger, desire to eat, and Satiety Labeled Intensity Magnitude Visual Analog Scale scores. In Study 1, all 3 psyllium doses resulted in directional or statistically significant mean reductions in hunger and desire to eat, and increased fullness between meals compared to placebo, with both higher doses better than placebo or 3.4 g. The 6.8 g dose provided more consistent (p ≤ 0.013) satiety benefits versus placebo. In Study 2, satiety was assessed similarly to Study 1. A significant (p ≤ 0.004) decrease in the 3-day mean hunger and desire to eat, as well as an increase in fullness for psyllium relative to placebo was observed. Most adverse events were mild gastrointestinal symptoms and were similar for psyllium compared to placebo. These results indicate that psyllium supplementation contributes to greater fullness and less hunger between meals., (Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Each of the macronutrients-carbohydrate, protein, and fat-has a unique set of properties that influences health, but all are a source of energy. The optimal balance of their contribution to the diet has been a long-standing matter of debate. Over the past half century, thinking has progressed regarding the mechanisms by which each macronutrient may contribute to energy balance. At the beginning of this period, metabolic signals that initiated eating events (i.e., determined eating frequency) were emphasized. This was followed by an orientation to gut endocrine signals that purportedly modulate the size of eating events (i.e., determined portion size). Most recently, research attention has been directed to the brain, where the reward signals elicited by the macronutrients are viewed as potentially problematic (e.g., contribute to disordered eating). At this point, the predictive power of the macronutrients for energy intake remains limited.

Nearly all Americans (97%) report eating candy at least once per year; yet, on a given day, only approximately one-fourth of the US population aged ≥2 y consumes candy. Among all Americans, candy contributes a relatively small proportion of calories, added sugars, and saturated fat to the total diet, and recent research suggests that current levels of candy consumption are not associated with risk of weight gain and cardiovascular disease in children and adults. Providing guidance for the consumption of candy in moderation requires an understanding of various behavioral health-related factors that influence candy consumption. A roundtable of behavioral nutrition experts, researchers, and nutrition educators met to discuss recent data on intakes of candy, health outcomes associated with usual candy intake, and the impact of behavioral strategies, including restriction, education, and environmental awareness, on modifying eating behaviors to achieve moderate intakes of candy. Restricting access to palatable foods, whether self-imposed or by parental control, may have potentially negative consequences. Techniques and insight into how to adopt "moderation" in candy consumption, from effective parental practices to environmental strategies that facilitate behavior change without a high degree of effort, were identified as important next steps toward sustainable dietary guidance related to the role of candy and other treats in a healthy lifestyle., (© 2015 American Society for Nutrition.)

To realize the health benefits associated with peanut consumption, it is important that they remain acceptable with regular intake. Peanuts are marketed with various flavorings so that consumers will not become fatigued by frequent consumption of any single flavor. This study sought to determine whether liking of peanuts or compliance to a peanut feeding intervention would differ based on receiving an individual flavor or a variety of flavors. Participants (n=151) were directed to consume 42 g peanuts/d for 12 weeks as 14-g servings of 3 different flavors (n=50) or a single flavor (n=25-26/group). The trial was randomized, with a parallel-group design. Neither the peanut flavor consumed nor the presence of variety had an impact on liking of the peanuts or compliance with the study protocol (p>0.05). Men had significantly greater compliance and liking ratings than women (p<0.05), but liking declines did not differ based on sex. Eating attitudes and dietary restraint did not correlate with liking or compliance. Peanuts were generally well-liked in the study, with a mean liking of 69 on a 100-mm visual analogue scale and a decrease of less than 15% over 12 weeks. Overall compliance to the protocol was 96.9%, suggesting participants were able to incorporate peanuts into their diet on a daily basis. These findings suggest a recommendation to regularly consume peanuts would be well-tolerated, facilitating their contribution to a healthy diet. The study was conducted between February 2010 and May 2012 at Purdue University, West Lafayette, IN, USA. This trial was registered at clinicaltrials.gov as NCT01886326., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Energy-yielding beverages reportedly contribute to positive energy balance uniquely. They are highly consumed and evoke weaker satiety signaling and dietary energy compensation than solid foods of the same energy content. This study measured the contribution of learning to appetitive sensations and adjustments of energy intake for preloads varying in energy content and food form in lean and obese adults. One-hundred seven participants received four preload trials before and after a dietary intervention in this randomized cross-over trial with the stipulation that lean and obese individuals were evenly assigned to each intervention. The study entailed monitoring appetitive sensations and daily energy intake after consumption of low and high energy beverage and solid food loads on weekly visit days. Preload testing was conducted at baseline, followed by daily ingestion of one load for 14 days and then retesting responses to the four treatments. Lean individuals compensated precisely for the high energy beverage and solid loads from the onset of the study, whereas the obese did not alter eating patterns after consuming the higher energy beverage load. The learning intervention did not have an effect on the responses to the preloads, as responses in both lean and obese participants did not differ from baseline values. Responses to personality and eating behavior questionnaires revealed differences between the lean and obese groups and weakly, but significantly, predicted challenge meal and total daily energy intake. These data suggest that lean and obese individuals respond to energy in beverage form differently, and this is not altered by purposeful daily exposure to loads varying in physical form and energy content for two weeks., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Background: The protein leverage hypothesis requires specific evidence that protein intake is regulated more strongly than energy intake., Objective: The objective was to determine ad libitum energy intake, body weight changes, appetite profile, and nitrogen balance in response to 3 diets with different protein-to-carbohydrate + fat ratios over 12 consecutive days, with beef as a source of protein., Design: A 3-arm, 12-d randomized crossover study was performed in 30 men and 28 women [mean ± SD age: 33 ± 16 y; body mass index (in kg/m²): 24.4 ± 4.0] with the use of diets containing 5%, 15%, and 30% of energy (En%) from protein, predominantly from beef., Results: Energy intake was significantly lower in the 30En%-protein condition (8.73 ± 1.93 MJ/d) than in the 5En%-protein (9.48 ± 1.67 MJ/d) and 15En%-protein (9.30 ± 1.62 MJ/d) conditions (P = 0.001), stemming largely from lower energy intake during meals (P = 0.001). Hunger (P = 0.001) and desire to eat (P = 0.001) ratings were higher and fullness ratings were lower (P = 0.001) in the 5En%-protein condition than in the 15En%-protein and 30En%-protein conditions. Nitrogen excretion was lower in the 5En%-protein condition (4.7 ± 1.5 g/24 h; P = 0.001) and was higher in the 30En%-protein condition (15.3 ± 8.7 g/24 h; P = 0.001) compared with the 15En%-protein condition (10.0 ± 5.2 g/24 h). Nitrogen balance was maintained in the 5En%-protein condition and was positive in the 15En%- and 30En%-protein conditions (P = 0.001)., Conclusions: Complete protein leverage did not occur because subjects did not consume to a common protein amount at the expense of energy balance. Individuals did underconsume relative to energy requirements from high-protein diets. The lack of support for protein leverage effects on a low-protein diet may stem from the fact that protein intake was sufficient to maintain nitrogen balance over the 12-d trial., (© 2014 American Society for Nutrition.)

Chewing reportedly contributes to satiation and satiety signals. Attempts to document and quantify this have led to small and inconsistent effects. The present trial manipulated oral processing effort though required chewing of gums of different hardness and measured appetitive sensations, energy intake, gastric emptying, GI transit time, and concentrations of glucose, insulin, GLP-1, ghrelin and pancreatic polypeptide. Sixty adults classified by sex and BMI (15 each of lean females, obese females, lean males and obese males) were tested in a randomized, controlled, cross-over trial with three arms. They chewed nothing, soft gum or hard gum for 15 min while sipping grape juice (10% of individual energy needs) containing acetaminophen and lactulose on one day each separated by 7 days. Electromyographic recordings and self-reports were obtained during and after chewing to quantify oral processing effort. Blood was sampled through an indwelling catheter and appetite ratings were obtained at baseline and at 0, 15, 30, 45, 60, 90, 120, 180 and 240 min after chewing initiation. Breath samples were collected at 10 min intervals for the first 2h and at 30 min intervals for the next 2h. No effects of chewing were observed for appetitive sensations or gut peptide concentrations. Energy intake tended to decline in lean and increase in obese participants so that daily energy intake differed significantly between the two groups when chewing either gum, while no difference was observed on the non-chewing day. Serum glucose and insulin were significantly lower at selected time points 90-240 min after chewing compared to baseline and the non-chewing day. These data indicate chewing effort does not affect appetitive sensations or gut peptide secretion, but may exert a small differential effect on acute energy intake in lean and obese individuals and lead to greater post-prandial declines of serum glucose and insulin. The efficacy of gum chewing as a substitute for eating for weight management remains uncertain., (© 2013.)

Background: Laboratory studies suggest that food form (beverages compared with solid foods) evokes behavioral and physiologic responses that modify short-term appetite and food intake. Beverage energy may be less satiating and poorly compensated, which leads to higher energy intake., Objective: We examined associations between 24-h energy consumed in beverages and a variety of meal and dietary attributes to quantify the contribution of beverage consumption to the energy content of diets in free-living individuals consuming their self-selected diets., Design: We used dietary recall data for adults (n = 13,704) in NHANES 2003-2008 to examine the multiple covariate-adjusted associations between 24-h energy from beverages and nonbeverages and associations between beverage intake, eating behaviors, and the energy density of beverage and nonbeverage foods., Results: In the highest tertile of 24-h beverage energy intake, beverages provided >30% of energy. Total 24-h energy and nonbeverage energy consumption and energy density (kcal/g) of both beverage and nonbeverage foods increased with increasing energy from beverages (P < 0.0001). With increasing 24-h beverage energy consumption, the reported frequency of all, snack, and beverage-only ingestive episodes and length of the ingestive period increased, whereas the percentage of energy from main meals decreased (P < 0.0001)., Conclusions: Higher 24-h beverage energy intake was related to higher energy intake from nonbeverage foods, quality of food selections, and distribution of 24-h energy into main meal and snack episodes. Moderation of beverage-only ingestive episodes and curtailing the length of the ingestion period may hold potential to lower uncompensated beverage energy consumption in the US population.

The sensory properties of foods and beverages are primary determinants of food choice. Some flavor components have an inherent hedonic valence that influences ingestive behavior. However, these hedonic impressions may be modified and others newly formed through their association with the post-ingestive consequences of food and beverage consumption. Flavor-active compounds, including spices, also modify digestive, absorptive and metabolic processes through direct activation of signaling pathways or via neurally-mediated cephalic phase responses. These may modify energy balance through effects on food digestion, energy absorption and metabolism. Thus, collectively, flavor has the potential to modify energy balance. Attempts to purposefully augment energy and nutrient intake have largely focused on the aging population where flavor fortification is posited to correct for diminishing sensory function. Evidence of efficacy is not strong, possibly due to methodological issues such as low statistical power and failure to match documented sensory limitations with the nature of the intervention. More rigorous testing should determine the viability of this therapeutic application of food flavors. The use of flavor compounds for weight reduction has yielded mixed results. Most trials have delivered the compounds via capsule precluding assessment of flavor to outcomes. Work with red pepper suggests there is an independent, albeit subtle, sensory effect on substrate oxidation coupled with a more general reduction of appetite and enhancement of energy expenditure. Flavor active compounds hold some promise for being more a part of the solution than the problem of disordered eating and unhealthy weight., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Beverage consumption has been implicated in weight gain, but questions remain about the veracity of the association, whether the relationship is causal and what property of beverages is responsible. It was hypothesized that food form is the most salient attribute. Thus, a randomized controlled trial of food form was conducted. Energy-matched beverage or solid forms of fruits and vegetables were provided to 34, lean or overweight/obese adults for two 8-week periods with a 3-week washout interspersed. Dietary compensation was incomplete (beverage 53%; solid 78%) and body weight increased after the beverage (1.95 ± 0.33 kg) (77% fat mass) and solid (1.36 ± 0.30 kg) (85% fat mass) treatments (both P < 0.0005). Differences between food forms were not significant. The lean group had the highest dietary compensation (119%) and no significant weight change (0.84 ± 0.53 kg) after consuming the solid fruits and vegetables whereas the overweight/obese group had lower compensation and significant weight gain during the solid arm (46%, 1.77 ± 0.32 kg, P < 0.0001). In contrast, incomplete dietary compensation and weight gain occurred in both the lean (43%, 1.61 ± 0.44 kg, P = 0.003) and overweight/obese (61%, 2.22 ± 0.47 kg, P < 0.0005) groups during the beverage arm. Secondary analyses revealed the obese group gained more weight than the lean and overweight groups during the beverage intervention (P = 0.024). These data demonstrate energy consumed as beverages may be especially problematic for weight gain. They also indicate that advice to increase fruit and vegetable consumption should emphasize total energy intake because the additional energy contributed may promote weight gain, especially among overweight and obese individuals.

Background: Beverage consumption is implicated in the overweight/obesity epidemic through the weaker energy compensation response it elicits compared with solid food forms. However, plausible mechanisms are not documented., Objective: This study assessed the cognitive and sensory contributions of differential postingestive responses to energy- and macronutrient-matched liquid (in beverage form) and solid food forms and identifies physiologic processes that may account for them., Design: Fifty-two healthy adults [mean ± SD age: 24.7 ± 5.5 y; BMI (in kg/m(2)): 26.3 ± 6.3] completed this randomized, 4-arm crossover study. Participants consumed oral liquid and solid preloads that they perceived, through cognitive manipulation, to be liquid or solid in their stomach (ie, oral liquid/perceived gastric liquid, oral liquid/perceived gastric solid, oral solid/perceived gastric liquid, or oral solid/perceived gastric solid). However, all preloads were designed to present a liquid gastric challenge. Appetite, gastric-emptying and orocecal transit times, and selected endocrine responses were monitored for the following 4 h; total energy intake was also recorded., Results: Oral-liquid and perceived gastric-liquid preloads elicited greater postprandial hunger and lower fullness sensations, more rapid gastric-emptying and orocecal transit times, attenuated insulin and glucagon-like peptide 1 release, and lower ghrelin suppression than did responses after oral-solid and perceived gastric-solid treatments (all P < 0.05). Faster gastric-emptying times were significantly associated with greater energy intake after consumption of perceived gastric-liquid preloads (P < 0.05). Energy intake was greater on days when perceived gastric-liquid preloads were consumed than when perceived gastric solids were consumed (2311 ± 95 compared with 1897 ± 72 kcal, P = 0.007)., Conclusions: These data document sensory and cognitive effects of food form on ingestive behavior and identify physical and endocrine variables that may account for the low satiety value of beverages. They are consistent with findings that clear, energy-yielding beverages pose a particular risk for positive energy balance. This study was registered at clinicaltrials.gov as NCT01070199.

Data are limited concerning the dietary factors that influence appetite control in older adults. This study examined the effects of food form and portion size on appetite in 43 older adults (age: 72 +/- 1 years; BMI: 25.6 +/- 0.3 kg/m(2)). Subjects were assigned to groups based on portion size of the test meal (12.5% (n = 18) vs. 25% (n = 25) of estimated energy need). Subjects randomly consumed, on two separate days, the respective solid or beverage test meal. Appetite sensations and hormonal responses were measured over 4 h. Main effects of food form (P < 0.05) and/or portion size (P < 0.05) were observed for each appetite sensation. Postprandial hunger and desire to eat were greater following beverage vs. solid meal (between 12.5% vs. 25%), whereas fullness was lower after beverage vs. solid meal (P < 0.05). Main effects of food form and/or portion size were observed for glucose, insulin, and ghrelin. Postprandial glucose and insulin concentrations were lower after beverage vs. solid meal (between 12.5% vs. 25%; all comparisons, P < 0.05) whereas beverage meal led to greater 4-h ghrelin vs. solid meal (P = 0.09). No main effects were observed for glucagon-like peptide-1 (GLP-1) or cholecystokinin (CCK). When adjusting for age, food form remained significant for postprandial hunger and fullness; portion size remained significant for postprandial glucose. Greater hunger and reduced satiety with accompanying glucose, insulin, and ghrelin following the beverage vs. solid meals, and to some extent, in smaller vs. larger portions suggest that appetite control is influenced by food form and portion size in older adults. These findings may enhance the development of appropriate dietary strategies that help to regulate energy balance.

Although thirst and hunger have historically motivated drinking and feeding, respectively, the high and increasing consumption of energy-yielding beverages and energy-diluted foods may have degraded the predictive value of these sensations on ingestive behavior. Our within subject (ie, multiple responses from the same individuals), observational (ie, free-living, with no intervention) study explored the relationships between thirst, hunger, eating, and drinking patterns in 50 weight-stable adults (39 women and 11 men aged 30+/-11 years with body mass index 26.3+/-5.9). Twenty-four-hour dietary recalls were obtained for a consecutive 7-day period. Appetite ratings were recorded hourly, over the same time period, and correlated with hourly energy and fluid intake from food and beverages. Thirst ratings were not correlated with drinking (r=0.03) or energy intake (r=0.08) during the same hour over the 7-day period. Hunger ratings were significantly, albeit moderately, correlated with energy intake (r=0.30) (P<0.05), but not with drinking (r=0.04). On average, 75% of total fluid intake was consumed during periprandial events. Further, energy-yielding beverages were the main contributor to fluid intake during both periprandial and drink-only events. These data fail to reveal associations between either thirst or hunger and ingestion of energy-yielding beverages, or strong associations between hunger and eating or thirst and drinking. These data raise questions about the predictive power of appetitive sensations for ingestive behavior.

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.

Nonnutritive sweeteners (NNS) are ecologically novel chemosensory signaling compounds that influence ingestive processes and behavior. Only about 15% of the US population aged >2 y ingest NNS, but the incidence is increasing. These sweeteners have the potential to moderate sugar and energy intakes while maintaining diet palatability, but their use has increased in concert with BMI in the population. This association may be coincidental or causal, and either mode of directionality is plausible. A critical review of the literature suggests that the addition of NNS to non-energy-yielding products may heighten appetite, but this is not observed under the more common condition in which NNS is ingested in conjunction with other energy sources. Substitution of NNS for a nutritive sweetener generally elicits incomplete energy compensation, but evidence of long-term efficacy for weight management is not available. The addition of NNS to diets poses no benefit for weight loss or reduced weight gain without energy restriction. There are long-standing and recent concerns that inclusion of NNS in the diet promotes energy intake and contributes to obesity. Most of the purported mechanisms by which this occurs are not supported by the available evidence, although some warrant further consideration. Resolution of this important issue will require long-term randomized controlled trials.

Nuts are a nutrient-rich food group. Depending on the type, they may provide substantive concentrations of Vitamin E, magnesium, folate, essential fatty acids, fiber and protein to the diet. They also contain potentially important phytochemicals. By mechanisms yet to be identified, they are reported to improve postprandial lipid profiles and may hold other health benefits. However, they are also energy dense so a theoretical contributor to positive energy balance and weight gain. However, epidemiological studies have consistently revealed an inverse association between the frequency of nut consumption and BMI. Further, intervention trials demonstrate less than predicted weight gain following inclusion of nuts in the diet. The mechanisms for these observations are currently under study. Candidates include strong satiety effects, promotion of energy expenditure and/or inefficient energy utilization. Recent trials have revealed support for each. Inclusion of nuts in the diet results in strong satiety effects as revealed by robust compensatory dietary responses that offset approximately 65-75% of the energy they provide. Several trials note increased energy expenditure that may account for an additional 10% of their energy yield. Limited bioaccessibility results in a loss of 5-15% of energy. Taken together, these findings largely account for the energy provided by nuts and explain the epidemiological and clinical observations. Thus, current knowledge suggests moderate nut consumption does not pose a threat for weight gain.

Appetite management may aid energy balance through moderation of the size (satiation) and/or frequency (satiety) of eating occasions. This double-blind, randomized, cross-over design study explored the effects of the addition of alginate and guar gum to a breakfast bar on appetite and food intake. Following baseline evaluations of health, appetite and diet, participants were randomized to receive the fiber containing bar or control bar. They reported to the laboratory after an overnight fast, rated their appetite and consumed the relevant 55 g bar within 10 min in place of their normal breakfast meal. Appetite ratings were again made immediately after consuming the bar and at 30 minute intervals for 5 h. This was repeated for 5 consecutive days (Monday-Friday) followed by a 9-day washout period and a similar 5-day treatment period with the alternate bar. Gastrointestinal tolerance was rated daily. Sensory ratings of the bars were obtained on the first and fifth study days. Twenty-four-hour diet recalls were conducted on three random days during baseline and each intervention period. No significant treatment effects were observed in self-reported appetitive sensations over each 5-hour post-loading period. There also was no evidence of a cumulative effect over the five treatment days. Daily energy intake was not different on the two treatments. Although these data do not support the efficacy of including guar and an alginate fiber combination in a solid food matrix for moderation of appetite and acute food intake, further testing of the concept under different conditions and with different forms of guar and alginate may prove worthwhile.

The concurrent increases of snacking and obesity suggest the possibility for some form of inter-meal oral stimulation with high satiety value to moderate rising obesity rates. This study explored the influence of sweetened chewing gum on appetitive ratings, meal patterning and food intake. Three test conditions were imposed after a fixed lunch preload: no gum chewing, gum chewing 2 h after lunch and gum chewing when hungry. Forty-seven participants, 29 males and 18 females, completed each treatment, one day a week for three weeks. Participants were fed lunch in a laboratory setting, and after being instructed on that day's test procedures, they were allowed to leave the laboratory. Throughout the remainder of the day, appetitive, mood and intake data were self-reported. The results indicate appetite ratings, meal patterning and food intake do not differ among the three treatment conditions. While these results did not support an effect of brief chewing of a sweetened gum, further exploration of variations of the sensory properties of gum and exposure patterns may still prove worthwhile.

The global prevalence of overweight and obesity is growing. Correction of the problem through dietary intervention has been disappointing and has prompted research into variations of diet composition or pattern to promote negative energy balance. Limited research suggests that selected approaches, such as low-carbohydrate diets, augment weight loss and offer an advantage over conventional low-fat diets. This has led to the hypothesis that although in theoretical terms a calorie is a calorie, in practice this is not the case. Support for such views and plausible mechanisms exist. Although any advantage may augment weight management, reported discrepancies between theoretical and observed effects are small. Thus, energy-restricted diets should be based primarily on energy intake and expenditure.

Objective: High glycemic index (GI)/load (GL) diets reportedly enhance appetite and promote positive energy balance. Support for this hypothesis stems largely from acute feeding trials and longer-term studies lacking control over the macronutrient composition and palatability of test foods. This study evaluated the effects of consuming high- and low-GI/GL meals, matched on macronutrient composition and palatability, plasma glucose and insulin, appetite, and food intake., Research Design and Methods: Thirty-nine healthy adults consumed only low- or only high-GI foods ad libitum in the laboratory for 8 days in either high (three foods per meal)- or low (one food per meal)-variety conditions. Glucose and insulin concentrations as well as appetitive sensations were determined before and for 2 h following breakfast and lunch on days 1 and 8. Energy intake was monitored daily., Results: There were no significant differences in plasma glucose or insulin responses, appetitive ratings, or food intake between treatments., Conclusions: These data indicate that the differential glycemic response of foods tested in isolation under fixed time are not preserved under conditions of chronic ad libitum consumption of mixed meals.

The effects of food unit size (FU) and energy density (ED) on food consumption were explored in 20 adults using a within subjects 2 x 2 design study. The four food treatment combinations were provided in the laboratory in random order on four non-consecutive days. The foods differed in FU (small food unit (SFU) or customary food unit (CFU)) and energy density, by manipulating fat content (low (LED) or high (HED)). Appetitive responses and total grams and kilocalories consumed were monitored. Hunger, fullness, desire to eat and prospective consumption ratings were not significantly different between treatments. Gram weight of food consumed was constant across all treatments. Energy intake of HED foods was greater than LED foods independent of food unit size for breakfast (F(1,17) = 11.77, p < 0.001), lunch (F(1,17) = 4.70, p < 0.05) and the 24 h period (F(1,17) = 8.99, p < 0.001) but only tended to be increased at dinner. In summary, appetitive sensations were not markedly altered by food unit size or energy density. The daily gram weight of food consumed and appetitive ratings were relatively consistent across treatments resulting in higher energy intake with HED foods.

Objectives: The primary aim was to determine whether ready-to-eat cereal used as a portion-controlled, meal replacement promotes weight loss. Additional aims were to determine whether weight loss differed if the cereal was provided as a single brand or variety of brands and whether this use of ready-to-eat cereal promotes continued weight loss following transition to a high-fiber, high-volume (Volumetric) diet., Methods: Body composition was measured and diet records, appetite questionnaires and activity logs were completed during baseline and end of intervention weeks 2 and 6. Participants were assigned to one of four treatment groups. Group 1 (6 M, 22 F, mean age 43.0 +/- 1.9 years, mean initial BMI 28.9 +/- 0.4 kg/m(2)) consumed a serving of a single brand of ready-to-eat cereal with 2/3 C skim milk and a 100 Kcal portion of fruit for breakfast and as a replacement for either lunch or dinner for weeks 1 and 2. No restrictions were placed on the non-cereal meal. They then followed the Volumetric diet for weeks 3 to 6 with a target energy restriction of 500 kcal/day. Group 2 (3 M, 25 F, mean age 40.9 +/- 2.3 years, mean initial BMI 29.39 +/- 0.6 kg/m(2)) followed the same protocol, but was permitted to select from a variety of ready-to-eat cereals during weeks 1 and 2. Group 3 (7 M, 19 F, mean age 41.6 +/- 2.4 years, mean initial BMI 29.3 +/- 0.6 kg/m(2)) received no dietary instruction during the six-week study and Group 4 (9 M, 18 F, mean age 38.2 +/- 2.8 years, mean initial BMI 29.3 +/- 0.6 kg/m(2)) received no intervention prior to adoption of the Volumetric diet for weeks 3 to 6., Results: The cereal interventions resulted in 640 +/- 109 and 617 +/- 105 kcal/day reductions of energy intake in Groups 1 and 2, respectively, during the two-week cereal intervention. This led to comparable mean weight losses (1.91 +/- 0.19 kg-Group 1, 1.37 +/- 0.15 kg-Group 2) that were significantly greater than that observed in Group 3 (0.08 +/- 0.15 kg). The losses were primarily of fat mass. No significant changes of total body water were observed. Weight loss continued during the Volumetric diet in Groups 1 and 2. The changes were comparable to those observed in Group 4, and all were significantly greater than that of Group 3. Self-reported hunger was slightly, but significantly higher than baseline in Groups 1 and 2 during the cereal intervention, but similar to baseline in Groups 1, 2 and 3 during the Volumetric diet. Based on predicted weight loss, compliance with the Volumetric diet was similar and limited in all three intervention groups., Conclusions: Ready-to-eat cereals may be used to promote weight loss when consumed as a portion-controlled, meal replacement. Provision of a variety of brands does not compromise efficacy. Weight losses may be maintained or increased after transition to the Volumetric diet. The later regimen effectively controls hunger and may lead to weight loss, but compliance is limited.

Background Low-calorie sweeteners (LCSs) provide sweetness with little or no energy. However, each LCS's unique chemical structure has potential to elicit different sensory, physiological, and behavioral responses that affect body weight. Objective The purpose of this trial was to compare the effects of consumption of 4 LCSs and sucrose on body weight, ingestive behaviors, and glucose tolerance over a 12-wk intervention in adults (18–60 y old) with overweight or obesity (body mass index 25–40 kg/m2). Methods In a parallel-arm design, 154 participants were randomly assigned to consume 1.25–1.75 L of beverage sweetened with sucrose (n  = 39), aspartame (n  = 30), saccharin (n  = 29), sucralose (n  = 28), or rebaudioside A (rebA) (n  = 28) daily for 12 wk. The beverages contained 400–560 kcal/d (sucrose treatments) or <5 kcal/d (LCS treatments). Anthropometric indexes, energy intake, energy expenditure, appetite, and glucose tolerance were measured at baseline. Body weight was measured every 2 wk with energy intake, expenditure, and appetite assessed every 4 wk. Twenty-four-hour urine collections were completed every 4 wk to determine study compliance via para-aminobenzoic acid excretion. Results Of the participants enrolled in the trial, 123 completed the 12-wk intervention. Sucrose and saccharin consumption led to increased body weight across the 12-wk intervention (Δweight = +1.85 ± 0.36 kg and +1.18 ± 0.36 kg, respectively; P  ≤ 0.02) and did not differ from each other. There was no significant change in body weight with consumption of the other LCS treatments compared with baseline, but change in body weight for sucralose was negative and significantly lower compared with all other LCSs at week 12 (weight difference ≥ 1.37 ± 0.52 kg, P  ≤ 0.008). Energy intake decreased with sucralose consumption (P  = 0.02) and ingestive frequency was lower for sucralose than for saccharin (P  = 0.045). Glucose tolerance was not significantly affected by any of the sweetener treatments. Conclusions Sucrose and saccharin consumption significantly increase body weight compared with aspartame, rebA, and sucralose, whereas weight change was directionally negative and lower for sucralose compared with saccharin, aspartame, and rebA consumption. LCSs should be categorized as distinct entities because of their differing effects on body weight. This trial was registered at clinicaltrials.gov as NCT02928653. [ABSTRACT FROM AUTHOR]

Abstract: Previous studies suggest consumption of red pepper (RP) promotes negative energy balance. However, the RP dose provided in these studies (up to 10g/meal) usually exceeded the amount preferred by the general population in the United States (mean=~1g/meal). The objective of this study was to evaluate the effects of hedonically acceptable RP doses served at a single meal in healthy, lean individuals on thermogenesis and appetite. Twenty-five men and women (aged 23.0±0.5years, BMI 22.6±0.3kg/m2, 13 spicy food users and 12 non-users) participated in a randomized crossover trial during which they consumed a standardized quantity (1g); their preferred quantity (regular spicy food users 1.8±0.3g/meal, non-users 0.3±0.1g/meal); or no RP. Energy expenditure, core body and skin temperature, and appetite were measured. Postprandial energy expenditure and core body temperature were greater, and skin temperature was lower, after test loads with 1g RP than no RP. Respiratory quotient was lower after the preferred RP dose was ingested orally, compared to in capsule form. These findings suggest that RP''s effects on energy balance stem from a combination of metabolic and sensory inputs, and that oral exposure is necessary to achieve RP''s maximum benefits. Energy intake was lower after test loads with 1g RP than no RP in non-users, but not in users. Preoccupation with food, and the desire to consume fatty, salty, and sweet foods were decreased more (or tended to be decreased more) in non-users than users after a 1g RP test load, but did not vary after a test load with no RP. This suggests that individuals may become desensitized to the effects of RP with long-term spicy food intake. [Copyright &y& Elsevier]

• A non-systemic, superabsorbent hydrogel device safely promotes weight loss. • Use of the hydrogel does not impact appetite, energy intake, or fecal excretion. • Prescribed diet increases appetitive sensations and cravings. As the obesity epidemic continues, there is a great need for safe and effective weight loss aids. A superabsorbent hydrogel device administered as a capsule demonstrates potential for weight loss, but its mechanism of action remains unclear. The present study's goal was to determine the mechanisms of action of the hydrogel through the investigation of its effects on appetitive sensations, eating behavior, energy intake, and fecal excretion of energy. Overweight and obese adults (n = 18) participated in a double-blind, randomized, crossover-design study in which they were provided all meals for a week in a supervised setting (i.e., controlled-feeding) and were required to either consume the hydrogel or a placebo with 16-oz of water 20 min before lunch and dinner. No differences in appetite (all, p > 0.05), total fecal nitrogen excretion (p = 0.74), total fecal fat excretion (p = 0.54), or total fecal energy excretion (p = 0.76) were identified when comparing the hydrogel to a placebo. Affect towards food (i.e., mood, emotions) was more positive in the hydrogel group compared with the placebo group. A subset of the controlled-feeding group (n = 10) then participated in another double-blind, randomized, crossover-design study in which they provided their own food for a week (i.e., free-feeding) and were required to either consume the hydrogel or a placebo with 16-oz of water 20 min before lunch and dinner. No differences in appetite (all, p > 0.05), energy intake (p = 0.95), diet quality (all, p > 0.05), or eating behavior (all, p > 0.05) were determined when comparing the hydrogel to the placebo. Future studies with greater statistical power should confirm these findings and investigate other potential mechanisms of action of the hydrogel. [ABSTRACT FROM AUTHOR]

Low calorie sweeteners (LCS) are prevalent in the food supply for their primary functional property of providing sweetness with little or no energy. Though tested for safety individually, there has been extremely limited work on the efficacy of each LCS. It is commonly assumed all LCS act similarly in their behavioral and physiological effects. However, each LCS has its own chemical structure that influences its metabolism, making each LCS unique in its potential effects on body weight, energy intake, and appetite. LCS may have different behavioral and physiological effects mediated at the sweet taste receptor, in brain activation, with gut hormones, at the microbiota and on appetitive responses. Further elucidation of the unique effects of the different commercially available LCS may hold important implications for recommendations about their use for different health outcomes. [ABSTRACT FROM AUTHOR]