The Cerebellar Response to Visual Portion Size Cues Is Associated with the Portion Size Effect in Children.

The neural mechanisms underlying susceptibility to eating more in response to large portions (i.e., the portion size effect) remain unclear. Thus, the present study examined how neural responses to portion size relate to changes in weight and energy consumed as portions increase. Associations were examined across brain regions traditionally implicated in appetite control (i.e., an appetitive network) as well as the cerebellum, which has recently been implicated in appetite-related processes. Children without obesity (i.e., BMI-for-age-and-sex percentile < 90; N = 63; 55% female) viewed images of larger and smaller portions of food during fMRI and, in separate sessions, ate four meals that varied in portion size. Individual-level linear and quadratic associations between intake (kcal, grams) and portion size (i.e., portion size slopes) were estimated. The response to portion size in cerebellar lobules IV-VI was associated with the quadratic portion size slope estimated from gram intake; a greater response to images depicting smaller compared to larger portions was associated with steeper increases in intake with increasing portion sizes. Within the appetitive network, neural responses were not associated with portion size slopes. A decreased cerebellar response to larger amounts of food may increase children's susceptibility to overeating when excessively large portions are served.

Fibre-rich Foods to Treat Obesity and Prevent Colon Cancer trial study protocol: a randomised clinical trial of fibre-rich legumes targeting the gut microbiome, metabolome and gut transit time of overweight and obese patients with a history of noncancerous adenomatous polyps.

INTRODUCTION: Recently published studies support the beneficial effects of consuming fibre-rich legumes, such as cooked dry beans, to improve metabolic health and reduce cancer risk. In participants with overweight/obesity and a history of colorectal polyps, the Fibre-rich Foods to Treat Obesity and Prevent Colon Cancer randomised clinical trial will test whether a high-fibre diet featuring legumes will simultaneously facilitate weight reduction and suppress colonic mucosal biomarkers of colorectal cancer (CRC). METHODS/DESIGN: This study is designed to characterise changes in (1) body weight; (2) biomarkers of insulin resistance and systemic inflammation; (3) compositional and functional profiles of the faecal microbiome and metabolome; (4) mucosal biomarkers of CRC risk and (5) gut transit. Approximately 60 overweight or obese adults with a history of noncancerous adenomatous polyps within the previous 3 years will be recruited and randomised to one of two weight-loss diets. Following a 1-week run-in, participants in the intervention arm will receive preportioned high-fibre legume-rich entrées for two meals/day in months 1-3 and one meal/day in months 4-6. In the control arm, entrées will replace legumes with lean protein sources (eg, chicken). Both groups will receive in-person and written guidance to include nutritionally balanced sides with energy intake to lose 1-2 pounds per week. ETHICS AND DISSEMINATION: The National Institutes of Health fund this ongoing 5-year study through a National Cancer Institute grant (5R01CA245063) awarded to Emory University with a subaward to the University of Pittsburgh. The study protocol was approved by the Emory Institutional Review Board (IRB approval number: 00000563). TRIAL REGISTRATION NUMBER: NCT04780477.

Does 'portion size' matter? Brain responses to food and non-food cues presented in varying amounts.

Larger portions of food elicit greater intake than smaller portions of food, particularly when foods are high in energy density (kcal/g; ED). The neural mechanisms underlying this effect remain unclear. The present study used fMRI to assess brain activation to food (higher-ED, lower-ED) and non-food (office supplies) images presented in larger and smaller (i.e., age-appropriate) amounts in 61, 7-8-year-olds (29 male, 32 female) without obesity. Larger amounts of food increased activation in bilateral visual and right parahippocampal areas compared to smaller amounts; greater activation to food amount (larger > smaller) in this cluster was associated with smaller increases in food intake as portions increased. Activation to amount (larger > smaller) was stronger for food than office supplies in primary and secondary visual areas, but, for office supplies only, extended into bilateral parahippocampus, inferior parietal cortex, and additional visual areas (e.g., V7). Activation was greater for higher-vs. lower-ED food images in ventromedial prefrontal cortex for both larger and smaller amounts of food; however, this activation extended into left lateral orbital frontal cortex for smaller amounts only. Activation to food cues did not differ by familial risk for obesity. These results highlight potentially distinct neural pathways for encoding food energy content and quantity.

Children's Energy Intake Generally Increases in Response to the Energy Density of Meals but Varies with the Amounts and Types of Foods Served.

BACKGROUND: Food energy density (ED; kcal/g) is positively related to energy intake in numerous studies. A recent secondary analysis proposed that when the ED of consumed food is above a breakpoint, adults sense calories and adjust meal size to minimize overconsumption. OBJECTIVES: We conducted a secondary analysis of measured intakes in preschool children to assess how meal energy intake was related to meal ED as well as to meal portions, eating occasions, and menus. METHODS: We analyzed weighed intakes from 6355 meals served to 94 children aged 3 to 5 y in 2 randomized crossover trials. We provided children with all their daily food and milk for multiple periods of 5 consecutive days in their usual childcare setting. We used linear mixed models with repeated measures to analyze the effects on energy intake of meal ED and meal weight, either as served or as consumed. RESULTS: Energy intake at meals was related to the ED and portions of served food and also to the ED and weight of consumed food (all P < 0.0001). Energy intake was also significantly affected by the eating occasion and the foods served on the menus. Children selectively ate higher-ED items, which were served in smaller amounts than lower-ED options. Meal energy intake was curvilinear across consumed ED; it initially increased (slope: 113 ± 2 kcal/ED unit) but decreased at higher-ED meals (deceleration: -11 ± 1 kcal/ED unit2) without evidence of a clear breakpoint. This trajectory may be attributable to the relatively limited portions of higher-ED foods that were served. CONCLUSIONS: Children's energy intake generally increased with greater ED; at higher-ED meals, however, energy intake decreased in a curvilinear manner without a clear breakpoint. This reduction in intake at higher ED could be explained by meal-related factors such as the portions served rather than by sensitivity to meal energy content. This study was registered at clinicaltrials.gov as NCT03010501 and NCT03242863.

Reasons for meal termination, eating frequency, and typical meal context differ between persons with and without a spinal cord injury.

Overeating associated with neurogenic obesity after spinal cord injury (SCI) may be related to how persons with SCI experience satiation (processes leading to meal termination), their eating frequency, and the context in which they eat their meals. In an online, cross-sectional study, adults with (n = 688) and without (Controls; n = 420) SCI completed the Reasons Individuals Stop Eating Questionnaire-15 (RISE-Q-15), which measures individual differences in the experience of factors contributing to meal termination on five scales: Physical Satisfaction, Planned Amount, Decreased Food Appeal, Self-Consciousness, and Decreased Priority of Eating. Participants also reported weekly meal and snack frequency and who prepares, serves, and eats dinner with them at a typical dinner meal. Analysis revealed that while Physical Satisfaction, Planned Amount, and Decreased Food Appeal were reported as the most frequent drivers of meal termination in both groups, scores for the RISE-Q-15 scales differed across the groups. Compared to Controls, persons with SCI reported Physical Satisfaction and Planned Amount as drivers of meal termination less frequently, and Decreased Food Appeal and Decreased Priority of Eating more frequently (all p < 0.001). This suggests that persons with SCI rely less on physiological satiation cues for meal termination than Controls and instead rely more on hedonic cues. Compared to Controls, persons with SCI less frequently reported preparing and serving dinner meals and less frequently reported eating alone (all p < 0.001), indicating differences in meal contexts between groups. Individuals with SCI reported consuming fewer meals than Controls but reported a higher overall eating frequency due to increased snacking (p ≤ 0.015). A decrease in the experience of physical fullness, along with a dependence on a communal meal context and frequent snacking, likely contribute to overeating associated with neurogenic obesity after SCI.

Poorer inhibitory control was related to greater food intake across meals varying in portion size: A randomized crossover trial.

Individuals eat more food when larger portions are served, and this portion size effect could be influenced by inhibitory control (the ability to suppress an automatic response). Inhibitory control may also relate to obesogenic meal behaviors such as eating faster, taking larger bites, and frequent switching between meal components (such as bites of food and sips of water). In a randomized crossover design, 44 adults ate lunch four times in the laboratory. Lunch consisted of a pasta dish that was varied in portion size (400, 500, 600, or 700 g) along with 700 g of water. Meals were video-recorded to assess meal duration and bite and sip counts, which were used to determine mean eating rate (g/min), mean bite size (g/bite), and number of switches between bites and sips. Participants completed a food-specific stop-signal task, which was used to calculate Stop-Signal Reaction Time (SSRT). Across participants, SSRT values ranged from 143 to 306 msec, where greater SSRT indicates poorer inhibitory control. As expected, serving larger portions increased meal intake (p < 0.0001); compared to the smallest portion, intake of the largest increased by 121 ± 17 g (mean ± SEM). SSRT did not moderate the portion size effect (p = 0.34), but individuals with poorer inhibitory control ate more across all meals: 24 ± 11 g for each one SD unit increase in SSRT (p = 0.035). SSRT was not related to eating rate or bite size (both p > 0.13), but poorer inhibitory control predicted greater switching between bites and sips, such that 1.5 ± 0.7 more switches were made during meals for each one SD unit increase in SSRT (p = 0.03). These findings indicate that inhibitory control can contribute to overconsumption across meals varying in portion size, potentially in part by promoting switching behavior.

Variety and portion size combine to increase food intake at single-course and multi-course meals.

Increases in food variety and portion size independently promote intake. Little is known about how these effects combine or how they depend on meal structure. In two randomized crossover experiments, once a week for four weeks, women ate a lunch meal that was varied in two properties: variety (low: three bowls of the favorite dish vs. high: three bowls, each with a different main dish) and portion size (small: 450 g vs. large: 600 g). In Experiment 1 (n = 42), dishes were served simultaneously and in Experiment 2 (n = 49), dishes were served sequentially over three courses. At each meal, the primary outcome of food intake was measured; additionally, we measured sensory-specific satiety (SSS; the relative hedonic decline of a food as it is eaten). In Experiment 1 (simultaneous structure) variety and portion size did not interact (p = 0.72) but both independently increased intake; participants consumed 15 ± 7 g more at meals with high variety compared to low and 57 ± 7 g more from large portions compared to small (both p < 0.03). Similarly, in Experiment 2 (sequential structure) variety and portion size did not interact (p = 0.99) but participants consumed 30 ± 8 g more at high-variety meals and 51 ± 8 g more from large portions (both p < 0.001). SSS was not influenced by portion size in either experiment (both p > 0.16) or by variety in Experiment 1 (p = 0.58), but SSS was smaller at high-variety meals in Experiment 2 (p = 0.001). Thus, variety and large portions promoted greater food intake for a similar or smaller hedonic decline, indicating these effects were facilitated by delayed SSS. At meals with either a simultaneous or sequential structure, high variety and large portions combined to increase intake, suggesting that these common properties act together to promote overconsumption.

Children at high familial risk for obesity show executive functioning deficits prior to development of excess weight status.

OBJECTIVE: The objective of this study was to determine whether children with healthy weight who vary by familial risk for obesity differ in executive functioning. METHODS: Children (age 7-8 years) without obesity (n = 93, 52% male) who differed by familial risk for obesity (based on maternal weight status) completed go/no-go and stop-signal tasks to assess inhibitory control and an N-back task to assess working memory. Dual energy x-ray absorptiometry measured adiposity. Linear and mixed-effect models assessed unique effects and relative importance analysis-quantified relative effects of familial risk and percent body fat. RESULTS: Children at high compared with low familial risk showed worse inhibitory control; however, child adiposity was not associated with inhibitory control. Both high familial risk and greater child adiposity were associated with worse N-back performance when cognitive demand was high (2-back), but not low (0- and 1-back). The relative effect of familial risk on executive functioning was 2.7 to 16 times greater than the relative effect of percent body fat. CONCLUSIONS: These findings provide initial evidence that deficits in executive functioning may precede the development of obesity in children at high familial risk for this disease. Additional family risk studies are needed to elucidate the pathways through which maternal obesity influences child executive functioning and risk for obesity.

Portion size affects food selection in an immersive virtual reality buffet and is related to measured intake in laboratory meals varying in portion size.

A crucial step for validating the utility of an immersive virtual reality (iVR) buffet to study eating behavior is to determine whether variations in food characteristics such as portion size (PS) are relevant predictors of food selection in an iVR buffet. We tested whether manipulating PS in an iVR buffet affects the weight of food selected, and whether this response to PS is similar to participants' measured intake when PS varies at laboratory meals. In a randomized crossover design, 91 adults (18-71 y; 64 females; BMI = 25.3 ± 5.7) used their iVR remote to select lunch and dinner portions from an iVR buffet before consuming a standardized lab meal at two visits separated by one week. The PS in the iVR buffet and lab meals varied between a standard PS and a large PS. This design enabled comparisons of PS effects between iVR and lab settings, despite the scale difference in food weight between the environments. Portion size significantly affected food selection and food intake (p < 0.001). Subjects selected an additional 350 g in iVR and consumed an additional 154 g of food in the lab meals when offered the large portion compared to the small portion. The effect of PS showed a similar percentage increase in iVR (36.5%) and lab meals (39.2%). There was no significant difference in the effect of PS between iVR and lab meals after accounting for scale differences in food weight between the environments. The response to PS was not influenced by subject characteristics such as body mass index, sex, or age. These results demonstrate the utility of iVR for replicating real-world eating behaviors and enhancing our understanding of the intricate dynamics of food-related behaviors in a variety of contexts.

Inter-individual differences in children's short-term energy compensation: a systematic review and meta-analysis.

BACKGROUND: The ability to regulate energy intake is often assessed using a preloading paradigm to measure short-term energy compensation. In children, large variability exists with this paradigm both within- and across- studies and is poorly understood. OBJECTIVES: This systematic review and meta-analysis aimed to better understand factors contributing to variability in children's energy compensation. We tested 1) whether children demonstrated "good" energy compensation, defined as adjusting meal intake commensurate with preload intake and 2) differences in children's energy compensation by child age, sex, and weight status (assessed both continuously and categorically). METHODS: Standard guidelines for systematic review were followed to search PubMed, PsychInfo, and Web of Science. Data on study design (preload form, preload-to-meal interval, preload energy difference, study setting) and participant characteristics (sex, age, weight status) were extracted from 29 experiments meeting inclusion criteria, and 13 were included in meta-analyses. COMPx (energy compensation index), a linear transformation comparing food intake following a high- vs. low-energy preload, was the outcome. Hedge's g was calculated, and random intercept-only models tested associations between COMPx and sex, age, and weight status. RESULTS: The systematic review revealed mixed results regarding children's energy compensation and the role of inter-individual differences. Meta-analytic models revealed that children undercompensated (overate) for preload energy (ß = -0.38; P = 0.008). Sex (ß = 0.11; P = 0.76), age (ß = 0.03; P = 0.75), and weight (assessed continuously; ß = -0.07, P = 0.37) were not related to compensation. Children with overweight/obesity (assessed categorically) undercompensated more than children with healthy weight (ß = 0.18; P = 0.04). CONCLUSIONS: The systematic review highlighted wide variability across studies, while the meta-analysis demonstrated differences in COMPx by child weight status but not by age or sex. Standardizing protocols across studies is recommended, along with designing adequately powered studies aiming to test inter-individual differences a priori. Alternative approaches to the use of COMPx are recommended to allow better characterization of children's energy compensation ability. This study was registered at PROSPERO as CRD42020197748.

Switching between foods: A potential behavioral phenotype of hedonic hunger and increased obesity risk in children.

CONTEXT: Reward-based eating is a trait that increases risk for eating in the absence of hunger (EAH) and obesity. Eating behaviors such as switching more frequently between different foods may increase intake during EAH by delaying the onset of sensory-specific satiation (SSS); however, this question has not been empirically tested. OBJECTIVES: 1) Test whether switching between foods mediates the relationship between reward-based eating and EAH intake. 2) Test whether switching between foods during EAH moderates the relationship between reward-based eating and weight status. METHODS: Data were analyzed from a study assessing decision-making in children (n = 63 children; 9.4 ± 1.4 years, 77.0 ± 22.4 BMI%tile). Reward-based eating was quantified using the Children's Eating Behaviour Questionnaire. EAH was assessed as the amount of palatable food consumed following ad libitum consumption of a standard meal. Videos of eating behavior were coded for eating time, number of different foods consumed, and food switches. Ordinary least squares regressions were conducted to test hypotheses. RESULTS: Switching was positively associated with EAH intake for both kcal (p < 0.01) and grams (p < 0.01) such that each additional switch was associated with an increased intake of 17.0 kcal or 3.5 gs. Switching mediated the relationship between reward-based eating and EAH (p < 0.01) such that more frequent switching fully accounted for the positive association between reward-based eating and EAH (ps < 0.01). While reward-based eating was also positively associated with weight status (p < 0.01), this association was moderated by food switching (p < 0.01) such that the relationship was stronger for children who switch more frequently (p < 0.01). CONCLUSIONS: Frequent switching between foods was positively associated with EAH intake and mediated the relationship between reward-based eating and EAH. Moreover, reward-based eating was more strongly related to weight status in children who switched more frequently. Thus, food switching may contribute to overconsumption and be an important behavioral indicator of increased obesity risk in children. Studies across multiple meals and contexts will help determine if switching is a reliable behavioral phenotype.

Children with lower ratings of executive functions have a greater response to the portion size effect.

Deficits in executive functions (EFs), a set of cognitive processes related to self-regulation, are associated with the development of obesity. Prior studies from our group showed that lower food-cue related activation in brain regions implicated in self-regulation was related to a larger portion size effect. We tested the hypothesis that lower EFs in children would be positively related to the portion size effect. Healthy weight children aged 7-8 y (n = 88), who varied by maternal obesity status, participated in a prospective study. At baseline, the parent primarily in charge of feeding completed the Behavior Rating Inventory of Executive Function (BRIEF2) to assess child EFs, including Behavioral (BRI), Emotional (ERI), and Cognitive (CRI) indices. At 4 baseline sessions, children consumed meals in which the portion sizes of foods (pasta, chicken nuggets, broccoli, and grapes) varied by visit (total meal weight of 769, 1011, 1256, or 1492g). Intake increased with increasing portions in a linear trajectory (p < 0.001). EFs moderated the portion size effect such that lower BRI (p = 0.003) and ERI (p = 0.006) were associated with steeper increases in intake as portions increased. As amount of food increased, children in the lowest functioning tertiles for BRI and ERI increased intake by 35% and 36%, respectively, compared to children in the higher tertiles. Increases in intake among children with lower EFs were for higher- but not lower-energy-dense foods. Thus, in healthy weight children who varied by obesity risk, lower parentally reported EFs were associated with a larger portion size effect, and these results were independent of child and parent weight status. Therefore, EFs may be target behaviors that could be strengthened to help children moderate excess intake in response to large portions of energy-dense foods.

Dimensions of sleep quality are related to objectively measured eating behaviors among children at high familial risk for obesity.

OBJECTIVE: The aim of this study was to evaluate whether dimensions of sleep quality were associated with homeostatic and hedonic eating behaviors among children with healthy weight (BMI-for-age < 90%) but varying maternal weight status. METHODS: A total of 77 children (mean [SD], age: 7.4 [0.6] years; BMI z score: -0.10 [0.7]) with healthy weight and high (n = 32) or low (n = 45) familial obesity risk based on maternal weight status were served an ad libitum meal (homeostatic eating) followed by palatable snacks to assess eating in the absence of hunger (EAH; hedonic eating). Habitual sleep quality was quantified from seven nights of wrist actigraphy. Partial correlations, adjusted for child energy needs, pre-meal hunger, food liking, and socioeconomic status, evaluated associations of sleep with meal intake and EAH. Additionally, sleep-by-obesity risk interactions were assessed. RESULTS: Greater sleep fragmentation was associated with higher homeostatic meal energy intake, but only among children at high familial obesity risk (p value for interaction = 0.001; ß high risk = 48.6, p = 0.001). Sleep fragmentation was not associated with total EAH but was related to higher and lower intake of carbohydrates (r = 0.33, p = 0.003) and fat (r = -0.33, p = 0.003), respectively. CONCLUSIONS: Adverse associations of poor sleep with energy intake may be amplified among children already predisposed to obesity. Furthermore, that fragmented sleep relates to preferential intake of carbohydrates over fat during EAH may suggest alterations in taste preferences with poor sleep.

The effects of snack foods of different energy density on self-served portions and consumption in preschool children.

It is recommended that preschoolers serve themselves their own food portions; however, it is unclear what factors influence the amount they select for consumption, and particularly how their selected portions are influenced by food properties such as energy density, volume, and weight. We offered preschool children snacks differing in energy density (ED) and investigated the effects on the amounts they served and then consumed. In a crossover design, 52 children aged 4-6 y (46% girls; 21% overweight) ate an afternoon snack on 2 days in their childcare classrooms. Before each snack time, children served the amount they would like to eat of 4 snacks presented in equal volumes but differing in ED (higher-ED: pretzels, cookies; lower-ED: strawberries, carrots). Across the 2 sessions, children were given their self-served amount of either pretzels (3.9 kcal/g) or strawberries (0.3 kcal/g) and intake was measured. Later, children tasted all 4 snacks and rated liking. Results showed that the portions children served themselves were influenced by their liking ratings (p = 0.0006), but after accounting for liking, the volumes they served were similar for all 4 foods (p = 0.27). At snack time, children ate a greater proportion of self-served strawberries (92 ± 4%) than pretzels (73 ± 4%; p = 0.0003), but because of the ED difference they consumed 55 ± 4 kcal more from pretzels than strawberries (p < 0.0001). The difference in snack intake by volume was not attributable to liking ratings (p = 0.87). That children served a consistent volume of similarly-liked snacks suggests that their portions were affected more by visual cues than by weight or energy content. Despite eating a greater volume of lower-ED strawberries, children consumed more energy from the higher-ED pretzels, highlighting the contribution of energy density to children's energy intake.

Food Properties and Individual Characteristics Influence Children's Intake Across Multiple Days of Weighed Assessments in Childcare Programs.

BACKGROUND: Because children often consume substantial proportions of their diets in childcare programs, it is critical to determine what they eat when served menus meeting dietary recommendations and how intake is related to individual characteristics. OBJECTIVES: Using weighed assessments, we characterized children's consumption across 15 daily menus and investigated the relationship between properties of the food consumed and child characteristics. METHODS: In 3 crossover trials in childcare centers that followed dietary guidelines, we provided and weighed all meals and snacks for 5 consecutive days. For this descriptive secondary analysis, we characterized primary outcomes (daily food weight, energy density, and energy intake) by including the most typical set of menus from each trial, yielding 603 daily intakes for 128 preschool children (15% with overweight or obesity). Physical activity was measured by accelerometry during childcare sessions. Children's appetitive traits were assessed by parental questionnaires. RESULTS: Both food properties and child characteristics were related to daily intake. More food was consumed from menus with greater food weight, and the energy density of consumed food was greater from menus with higher energy density (both P < 0.0001); these menu differences resulted in greater energy intake (P = 0.009). Children with overweight and obesity had greater energy intake as a proportion of requirements than did children with healthy weight (113 ± 6% versus 101 ± 2%; P = 0.039). Vegetable intake was 39 ± 2% of the recommended amounts and boys had lower consumption than girls (P = 0.004). Children with appetitive traits of lower satiety responsiveness or higher food responsiveness had greater daily energy intake (both P < 0.003). CONCLUSIONS: Weighed intakes showed that when children were served daily menus with substantial portions of foods that met dietary recommendations, they selectively consumed higher-energy-dense items and ate few vegetables. A particular concern was that children with overweight ate amounts that exceeded their energy needs. The trials were registered at clinicaltrials.gov (NCT02963987, NCT03010501, NCT03242863).

Switching between bites of food and sips of water is related to food intake across meals varying in portion size.

Individuals eat more when served more food, but little is known about how this portion size effect is moderated by meal-related characteristics, particularly the inclusion of water served as a beverage. Patterns of eating and drinking as well as consumption of water could affect satiation by modifying exposure to the sensory qualities of food. In a crossover design, 44 adults ate lunch in the laboratory once a week for 4 weeks and intake was measured. The meal was a pasta dish that was varied in portion size (400, 500, 600, or 700 g) plus 700 g of water. Meals were video-recorded to count bites and sips and the number of switches between them. Sensory-specific satiety (SSS) was evaluated as the relative decline in hedonic ratings of the pasta after consumption. Serving larger portions led to a curvilinear increase in food intake (p < 0.0001). Neither switching between bites and sips nor water intake moderated the portion size effect. Independent of portion served, across all meals switching more frequently was related to greater food consumption (5.7 ± 1.8 g more food consumed for each additional switch, p = 0.004). Greater water intake was also related to greater food intake across portions (1.1 ± 0.5 g more food consumed for each additional 10 g of water, p = 0.025), but this effect was not significant after accounting for switching (p = 0.38). The magnitude of SSS was unaffected by switching, suggesting that switching allowed greater food intake for a given hedonic decline. At a meal with a single food, intake was greater when larger portions were served and also when there was more switching between bites and sips. Switching between food and water may promote energy intake by attenuating the development of SSS.

Eating rate and bite size were related to food intake across meals varying in portion size: A randomized crossover trial in adults.

Serving larger portions leads to increased food intake, but behavioral factors that influence the magnitude of this portion size effect have not been well characterized. We investigated whether measures of eating microstructure such as eating rate and bite size moderated the portion size effect. We also explored how sensory-specific satiety (SSS; the relative hedonic decline of a food as it is eaten) was affected by eating microstructure and larger portions. In a randomized crossover design, 44 adults aged 18-68 y (66% women; 46% with overweight and obesity) ate lunch in the laboratory once a week for 4 weeks. The meal consisted of pasta that was varied in portion size (400, 500, 600, or 700 g) and 700 g of water. Meals were video-recorded to assess bite count and meal duration, which were used to calculate mean eating rate (g/min) and mean bite size (g/bite). At each meal participants also completed an assessment of SSS. The results showed that as larger portions were served, meal intake increased in a curvilinear manner (p < 0.0001). Measures of eating microstructure did not moderate the portion size effect but were related to intake across all portions; faster eating rate, larger bite size, higher bite count, and longer meal duration were associated with greater consumption at all meals (all p < 0.0001). SSS was not influenced by any measure of eating microstructure or by portion size (all p > 0.10). In summary, the portion size effect was not moderated by eating microstructure, but relatively faster eating rates and larger bite sizes at meals, along with large portions, combined to increase food intake.

Children's Portion Selection Is Predicted by Food Liking and Is Related to Intake in Response to Increased Portions.

BACKGROUND: When children choose amounts of food to eat, it is unclear what influences the portions they select and whether their selections are related to the amounts they consume. OBJECTIVES: Using a computer survey, we investigated the effect of food liking on portion selection in middle childhood and examined how children's selections were related to measured intake at meals in which portions of all foods were varied across 4 test days. METHODS: Fifty-one children aged 7-10 y completed a computer survey of 20 common foods with a range of energy density. For each food, the survey presented sliding scales with 5 images varying in portion size and children indicated their liking and the amount they would eat at a specified meal or snack. On 4 test days in a randomized crossover design, children were served a meal of 6 foods from the survey with portions of 100%, 133%, 167%, or 200% of baseline amounts. Data were analyzed using random coefficients models. RESULTS: Across the 20 foods used in the survey, portion selection ratings were predicted by food liking ratings (P < 0.0001). After accounting for liking, portion selection ratings did not vary by food energy density (P = 0.50). At the meals, intake of all 6 foods increased when larger portions were served (P = 0.002). Furthermore, the selected portion of a food on the survey was positively related both to intake of that food at the 100%-portion meal (P = 0.014) and to increased intake as larger portions were served (P < 0.0001). CONCLUSIONS: Children aged 7-10 y were able to use a computer survey to choose food portions that predicted their measured intake in response to increased portions. The relation of liking to selection and intake indicates that to promote children's consumption of larger portions of low-energy-dense foods such as fruits and vegetables, these foods must be well liked by the children. This trial was registered at clinicaltrials.gov as NCT02759523.

Examining the Role of Food Form on Children's Self-Regulation of Energy Intake.

Increasing childhood obesity rates in both the United States and worldwide demonstrate a need for better prevention and intervention strategies. However, little is understood about what factors influence children's ability to sense and respond to hunger and fullness cues, a critical component of self-regulation of energy intake and maintenance of a healthy body weight. Research in adults suggests that food form may influence self-regulation of energy intake. More specifically, beverages are not as satiating as solid foods when matched for factors such as energy content, energy density, and volume and therefore elicit poorer energy intake self-regulation. However, much less is known about the impact of food form on children's ability to regulate their energy intake. This report describes a study that will examine the relationship between biological, cognitive, and psychological factors and children's appetite self-regulation (ASR). In this registered report, we will examine the influence of food form on children's short-term energy compensation, a proxy indicator of energy intake self-regulation. The study will employ a within-subjects, crossover design in which children (n = 78) ages 4.5-6 years will attend five laboratory visits, each ~1 week apart. During each visit, children will be presented with one of five possible preload conditions: apple slices, apple sauce, apple juice, apple juice sweetened with non-nutritive sweetener (NNS), or no preload. The order of preload conditions will be pseudorandomized and counterbalanced across participants. Following consumption of the preload (or no preload), children will consume a standardized ad libitum test meal of common foods for this age group. We hypothesize that children will demonstrate poorer short-term energy compensation (greater meal intake) in response to the liquid and semi-solid preloads compared to the solid preload. Understanding how energy in various forms affects children's ability to self-regulate intake has implications for dietary recommendations and will help identify those who are most at-risk for poor intake regulation and the development of obesity.

Does labelling a food as 'light' vs. 'filling' influence intake and sensory-specific satiation?

Although several studies have investigated the influence of nutrition labelling on food intake, the effect of labels indicating a food's satiating power on food intake and sensory-specific satiation (SSS) is poorly understood. We investigated whether providing information about the satiating power of a meal affects intake and SSS. Participants (19 men and 18 women) consumed the same test meal of pasta salad ad libitum on two occasions, once described as 'light' and once as 'filling'. SSS was determined as the change in liking of the flavor and desire to eat the test meal before and after consumption, compared to seven uneaten foods. As hypothesized, intake increased by a mean (±SD) of 31 ± 59 g and 42 ± 81 kcal when the meal was labelled 'light' as opposed to 'filling' (p < 0.01). After eating, ratings for both liking and desire to eat decreased significantly more for the test meal than for the uneaten control foods (p < 0.001), demonstrating SSS. These relative changes in liking and desire to eat did not differ between the label conditions, despite differences in intake. Furthermore, accounting for amount consumed, the magnitude of SSS did not differ between the label conditions, which suggests that it did not explain the effect of the labels on intake. This study shows that labels indicating the satiating power of a meal can affect intake, warranting caution in the use of such labels on products intended to reduce intake.