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.

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.

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.

Portion size can be used strategically to increase intake of vegetables and fruits in young children over multiple days: a cluster-randomized crossover trial.

BACKGROUND: Although dietary guidelines recommend that vegetables and fruits make up half the diet, it is unclear whether serving vegetables and fruits in larger portions will have sustained effects on children's intake over multiple days. OBJECTIVES: This study tested the effects on children's intake of 2 strategies for increasing the proportion of vegetables and fruits: either adding or substituting extra portions as side dishes at meals and snacks over 5 d. METHODS: In a cluster-randomized crossover design with 3 periods, we provided all meals and snacks for 5 d to 53 children aged 3-5 y in classrooms in their childcare centers. In the Control condition, we served typical portions for all food groups. In the Addition condition we increased portions of low-energy-dense vegetables and fruits by 50%, and in the Substitution condition we increased portions of vegetables and fruits by 50% and also reduced portions of other foods by an equivalent weight. RESULTS: For vegetables, the Addition strategy increased daily intake compared with Control by 24% (mean ± SEM = 12 ± 3 g/d; P = 0.0002), and the Substitution strategy increased intake compared with Control by 41% (22 ± 3 g/d; P < 0.0001). For fruits, consumption increased by similar amounts: Addition by 33% (60 ± 6 g/d) and Substitution by 38% (69 ± 8 g/d; both P < 0.0001). Both strategies increased vegetable and fruit intakes compared with Control across all 5 days (all P < 0.004), although the increase in fruit consumption with Addition declined over time (P < 0.0001). Daily energy intake compared with Control increased by 5% with Addition (57 ± 17 kcal; P = 0.001) but decreased by 6% with Substitution (-64 ± 21 kcal; P = 0.004). CONCLUSIONS: Both the Addition and Substitution strategies promoted increases in vegetable and fruit intake over 5 d in preschool children. When excess energy intake is a concern, substituting vegetables and fruits for other foods is a better option than simply serving more.This trial was registered at http://www.clinicaltrials.gov as NCT03242863 (https://clinicaltrials.gov/ct2/show/NCT03242863), where the protocol is available.

Promoting vegetable intake in preschool children: Independent and combined effects of portion size and flavor enhancement.

This study investigated the independent and combined effects on preschool children's vegetable intake of serving a larger portion of vegetables and enhancing their flavor. In a crossover design, lunch was served in childcare centers once a week for four weeks to 67 children aged 3-5 y (26 boys, 41 girls). The meal consisted of two familiar vegetables (broccoli and corn) served with fish sticks, rice, ketchup, applesauce, and milk. Across the four meals, we varied the portion of vegetables (60 or 120 g total weight, served as equal weights of broccoli and corn) and served them either plain or enhanced (6.6% light butter and 0.5% salt by weight). All meals were consumed ad libitum and were weighed to determine intake. Doubling the portion of vegetables led to greater consumption of both broccoli and corn (both p < 0.0001) and increased meal vegetable intake by 68% (mean ± SEM 21 ± 3 g). Enhancing vegetables with butter and salt, however, did not influence their intake (p = 0.13), nor did flavor enhancement modify the effect of portion size on intake (p = 0.10). Intake of other meal components did not change when the vegetable portion was doubled (p = 0.57); thus, for the entire meal, the increase in vegetable consumption led to a 5% increase in energy intake (13 ± 5 kcal; p = 0.02). Ratings indicated that children had similar liking for the plain and enhanced versions of each vegetable (both p > 0.31). All versions of vegetables were well-liked, as indicated by ≥ 76% of the children rating them as "yummy" or "just okay". Serving a larger portion of vegetables at a meal was an effective strategy to promote vegetable intake in children, but when well-liked vegetables were served, adding butter and salt was not necessary to increase consumption.

Development and validation of the Reasons Individuals Stop Eating Questionnaire (RISE-Q): A novel tool to characterize satiation.

A variety of factors can influence satiation, and individual differences in reasons for meal termination may help to explain variability in food intake and susceptibility to overconsumption. We developed and validated a questionnaire to characterize the Reasons Individuals Stop Eating (RISE-Q). The initial RISE-Q was created by reviewing the published literature and identifying 47 reasons why individuals might stop eating. The RISE-Q asks respondents to rate how often each reason influences why they stop eating at a typical dinner meal by using a seven-point scale. Adults (N = 477, 77% women) from a participant database completed a survey online that included the initial RISE-Q and the satiation-related Satiety Responsiveness and Food Responsiveness scales of the Adult Eating Behavior Questionnaire (AEBQ). Self-reported height and weight were collected to calculate body mass index (BMI). The survey also assessed self-reported typical meal size. After factor analysis, the RISE-Q retained 31 items and identified five distinct scales of reasons for stopping eating: Decreased Food Appeal (mean ± SD: 2.6 ± 0.05, Cronbach's α = 0.89), Physical Satisfaction (5.0 ± 0.04, α = 0.85), Planned Amount (4.4 ± 0.05, α = 0.82), Self-Consciousness (2.4 ± 0.05, α = 0.88), and Decreased Priority of Eating (2.3 ± 0.04, α = 0.69). Thus, the most frequently reported reasons for meal termination were related to Physical Satisfaction and Planned Amount. Each RISE-Q scale was significantly correlated with at least one of the satiation-related AEBQ scales, suggesting that the RISE-Q has construct validity. RISE-Q scales were also correlated with BMI and measures of typical meal size. The RISE-Q provides a novel tool to assess differences across individuals in reported reasons for eating cessation. The RISE-Q can aid in further understanding risk factors for overconsumption and has potential clinical utility in the design of targeted weight-management interventions.

Which strategies to manage problem foods were related to weight loss in a randomized clinical trial?

Individuals managing their weight are often faced with problem foods that are difficult to resist eating. In the context of a weight-loss intervention, we characterized the most commonly reported problem foods and the behavioral strategies used to manage them, and examined which strategies were related to weight loss. Women with overweight and obesity (N = 186) participated in a one-year randomized trial of three interventions (NCT01474759): standard advice to eat less food, choosing portions based on energy density, and using pre-portioned foods. At Months 0, 6, and 12 of the trial, participants listed the foods they found most problematic and reported the frequency of using eight behavioral strategies to control intake of these foods, including three practices for avoiding exposure to problem foods and three for consuming them but limiting intake. The responses showed that 82% of the top three problem foods were in the categories of sweet baked items, salty snacks, starchy side dishes, chocolate and candy, and ice cream. After one year, women who reported more frequently using the strategy of limiting portions of problem foods had a greater rate of weight loss (kg/week), regardless of their intervention group (p < 0.0001). Among women who limited portions of problem foods less frequently, those using pre-portioned foods had greater initial weight loss compared to the other two groups, but then regained weight at a greater rate (p < 0.0001). The three avoidance strategies for problem foods were reported to be frequently used but were not found to be related to weight loss. These results suggest that adopting and maintaining strategies to manage portions of problem foods, rather than avoiding exposure to them, can be a more useful approach for weight loss.

Portion size has sustained effects over 5 days in preschool children: a randomized trial.

BACKGROUND: Although short-term studies have found that serving larger portions of food increases intake in preschool children, it is unknown whether this portion size effect persists over a longer period or whether energy intake is moderated through self-regulation. OBJECTIVES: We tested whether the portion size effect is sustained in preschool children across 5 consecutive days, a period thought to be sufficient for regulatory systems to respond to the overconsumption of energy. METHODS: With the use of a crossover design, over 2 periods we served the same 5 daily menus to 46 children aged 3-5 y in their childcare centers. In 1 period, all foods and milk were served in baseline portions, and in the other period, all portions were increased by 50%. The served items were weighed to determine intake. RESULTS: Increasing the portion size of all foods and milk by 50% increased daily consumption: weighed intake increased by a mean ± SEM of 143 ± 21 g/d (16%) and energy intake increased by 167 ± 22 kcal/d (18%; both P < 0.0001). The trajectories of intake by weight and energy across the 5-day period were linear and the slopes did not differ between portion conditions (both P > 0.13), indicating that there were sustained increases in intake from larger portions without compensatory changes over time. Children differed in their response to increased portions: those with higher weight status, lower ratings for satiety responsiveness, or higher ratings for food responsiveness had greater increases in intake from larger portions (all P < 0.03). CONCLUSIONS: This demonstration that preschool children failed to adjust their intake during prolonged exposure to larger portions challenges the suggestion that their self-regulatory behavior is sufficient to counter perturbations in energy intake. Furthermore, overconsumption from large portions may play a role in the development of overweight and obesity, as the magnitude of the effect was greater in children of higher weight status. This trial was registered at www.clinicaltrials.gov as NCT02963987.

Both increases and decreases in energy density lead to sustained changes in preschool children's energy intake over 5 days.

BACKGROUND AND OBJECTIVE: To investigate preschool children's ability to self-regulate their energy intake, we assessed their response to increases or decreases in dietary energy density (ED) over 5 consecutive days, a period likely long enough for compensatory behavior. METHODS: Using a crossover design, over 3 periods we served the same 5 daily menus to 49 children aged 3-5 y in their childcare centers. During each 5-day period, 3 main dishes and 1 snack per day were systematically varied in ED, from baseline ED to either higher ED (increased by 20%) or lower ED (decreased by 20%). All of the served items were weighed to determine individual intakes. RESULTS: Modifying the ED of 4 dishes per day had a significant and sustained effect on preschool children's daily energy intake across 5 days. In the baseline condition, children's intakes were similar to daily energy needs (98 ±â€¯2%), but serving higher-ED foods increased energy intake by 84 ±â€¯16 kcal/d (to 105 ±â€¯2% of needs) and serving lower-ED foods decreased energy intake by 72 ±â€¯17 kcal/d (to 89 ±â€¯2% of needs; both P < .0001). The patterns of daily energy intake over the 5 days did not differ across conditions (P = .20), thus there was no evidence that either surfeits or deficits in energy intake led to adjustment over this time period. Furthermore, the response to ED varied, as children with a higher weight status had greater amounts of overconsumption when served higher-ED foods and of underconsumption when served lower-ED foods compared to children with a lower weight status. CONCLUSIONS: These findings counter the suggestion that preschool children's regulatory systems can be relied on to adjust intake in response to energy imbalances. Increasing or decreasing the ED of several foods per day leads to sustained changes in the energy intake of preschool children.

Doggy bags and downsizing: Packaging uneaten food to go after a meal attenuates the portion size effect in women.

Serving larger portions leads to increased food and energy intake, but little is known about strategies to moderate this response. This study tested how the effect of portion size on meal intake was influenced by providing the option to take away uneaten food in a "doggy bag" (to-go container). Women were randomly assigned to one of two subject groups: a To-Go Group (n = 27) that was informed before each meal that their leftover food would be packaged to take away after the meal, and a Control Group (n = 26) that was not given this option. In a crossover design, subjects came to the lab once a week for four weeks to eat a dinner composed of five foods. Across meals, the portion size of all foods was varied (100%, 125%, 150%, and 175% of baseline). Results showed that the portion size effect, defined as the trajectory of intake across the weight of food served, differed significantly by subject group (P ≤ 0.025). In the Control Group, increasing the portion size of all foods led to substantial increases in intake (P < 0.0001); for every 100 g added to the baseline portion, women in this group consumed an additional mean (±SEM) of 64 ±â€¯12 g of food and 90 ±â€¯19 kcal, until intake leveled off. In contrast, intake of women in the To-Go Group increased by only 17 ±â€¯12 g and 19 ±â€¯18 kcal for every additional 100 g served; these increases did not differ significantly from zero (P > 0.15). Thus, the effect of portion size on intake was attenuated in the To-Go Group compared to the Control Group. These data indicate that packaging uneaten food after a meal could be an effective strategy to reduce overconsumption from large portions.

Does the cost of a meal influence the portion size effect?

Serving larger portions leads to increased intake, but little is known about how the cost of a meal affects this response. Therefore, we tested whether the amount of money paid for a meal influenced the portion size effect at a lunch served in a controlled restaurant-style setting. In a crossover design, 79 adults (55 women; 24 men) came to the lab once a week for 4 weeks to eat a main dish of pasta with side dishes. Across weeks, the meal was varied in two factors: portion size of the main dish (400 g or 600 g) and cost of the meal (US$8 or $16). At discharge subjects completed questionnaires that assessed behaviors thought to influence the response to portion size and cost. Results showed that the portion size of the main dish had a significant effect on meal intake (P < 0.0001). The weight of food consumed at the meal increased by 18 ±â€¯2% (mean ±â€¯SEM 83 ±â€¯11 g) and energy intake increased by 20 ±â€¯2% (133 ±â€¯16 kcal) when the larger portion was served. These effects of portion size did not differ across the two levels of cost (both interactions P > 0.37) nor did meal cost have significant effects on meal intake (both P > 0.24). Subject scores for satiety responsiveness did, however, influence the effect of portion size on food intake (P = 0.0007). Serving larger portions led to increased intake in subjects with lower satiety responsiveness scores (P < 0.0001), but did not affect intake in those with higher scores. In summary, the effect of portion size on intake in a restaurant-style setting was not influenced by meal cost but was attenuated in individuals higher in satiety responsiveness.

Comparing the portion size effect in women with and without extended training in portion control: A follow-up to the Portion-Control Strategies Trial.

Following a 1-year randomized controlled trial that tested how weight loss was influenced by different targeted strategies for managing food portions, we evaluated whether the effect of portion size on intake in a controlled setting was attenuated in trained participants compared to untrained controls. Subjects were 3 groups of women: 39 participants with overweight and obesity from the Portion-Control Strategies Trial, 34 controls with overweight and obesity, and 29 controls with normal weight. In a crossover design, on 4 different occasions subjects were served a meal consisting of 7 foods that differed in energy density (ED). Across the meals, all foods were varied in portion size (100%, 125%, 150%, or 175% of baseline). The results showed that serving larger portions increased the weight and energy of food consumed at the meal (P < .0001), and this effect did not differ across groups. Increasing portions by 75% increased food intake by a mean (±SEM) of 111 ±â€¯10 g (27%) and increased energy intake by 126 ±â€¯14 kcal (25%). Across all meals, however, trained participants had lower energy intake (506 ±â€¯15 vs. 601 ±â€¯12 kcal, P = .006) and lower meal ED (1.09 ±â€¯0.02 vs. 1.27 ±â€¯0.02 kcal/g; P = .003) than controls, whose intake did not differ by weight status. The lower energy intake of trained participants was attributable to consuming meals with a greater proportion of lower-ED foods than controls. These results further demonstrate the robust nature of the portion size effect and reinforce that reducing meal ED is an effective way to moderate energy intake in the presence of large portions.

The Weight-Related Eating Questionnaire offers a concise alternative to the Three-Factor Eating Questionnaire for measuring eating behaviors related to weight loss.

OBJECTIVE: During a one-year weight loss trial, we compared the Three-Factor Eating Questionnaire (TFEQ), a valid 51-item measure of restraint, disinhibition, and hunger subscales, with the newer 16-item Weight-Related Eating Questionnaire (WREQ) measuring routine and compensatory restraint and external and emotional eating. METHODS: Both questionnaires were administered to women with overweight or obesity (n = 186, mean ± SD, age 50 ± 10.6 y, BMI 34 ± 4.2 kg/m2) at five time points. Completion rates were 100% at baseline and Month 1, 94% at Month 3, 83% at Month 6, and 76% at Month 12. Confirmatory factor analysis was conducted on baseline WREQ data and correlations were calculated between TFEQ and WREQ subscales. Multilevel models evaluated the relationship between each subscale and weight change over time. RESULTS: Factor analysis revealed a WREQ structure consistent with previous research, and corresponding subscales on the TFEQ and WREQ were correlated. Lower baseline TFEQ restraint predicted greater weight loss. Across five administrations, TFEQ and WREQ restraint scores were positively related to weight loss (p < 0.01) and TFEQ disinhibition and WREQ external and emotional eating scores were negatively related (p < 0.001). Thus, with one baseline administration, only TFEQ restraint was significantly related to weight change, but multiple administrations showed relationships between all TFEQ and WREQ subscales and weight change. CONCLUSIONS: The WREQ offers a shorter alternative to the TFEQ when repeatedly assessing eating behaviors related to weight change.

Does milk matter: Is children's intake affected by the type or amount of milk served at a meal?

Increasing the energy density (ED) and portion size of foods promotes additional energy intake, but the effect of similar changes in milk is unknown. Using a crossover design, we tested the effect of varying the ED and portion size of milk served with lunch on preschool children's intake. Lunch was served in childcare classrooms on 4 days to 125 children aged 3-5 y (67 boys; 58 girls). Across the meals, milk was varied in ED (lower-ED [1% fat]; higher-ED [3.25% fat]) and portion size (100% [183 g]; 150% [275 g]). Foods in the meal were not varied; children ate as much of the meal as they wanted. Serving higher-ED milk did not affect milk intake by weight, but increased energy intake from milk by 31 ± 2 kcal compared to serving lower-ED milk (P < 0.0001). Serving the 150% portion of milk increased milk intake by 20 ± 3 kcal compared to serving the 100% portion (P < 0.0001). Increases in both ED and portion size combined to increase milk intake by 49 ± 4 kcal (63%; P < 0.0001). Across all children, food intake decreased when higher-ED rather than lower-ED milk was served, but meal energy intake (food + milk) did not change significantly. This response varied by sex: for boys, serving higher-ED milk decreased food intake by 43 ± 8 kcal (P < 0.0001) but did not affect meal energy intake, while for girls, higher-ED milk did not reduce food intake so that meal energy intake increased by 24 ± 10 kcal (P = 0.03). Thus, boys adjusted food intake in response to changes in ED of milk consumed with lunch, but girls did not. Serving milk in larger portions promotes intake of this nutrient-dense beverage, but the effects of milk ED on meal intake vary between children.

Double trouble: Portion size and energy density combine to increase preschool children's lunch intake.

BACKGROUND: Both portion size and energy density (ED) have substantial effects on intake; however, their combined effects on preschool children's intake have not been examined when multiple foods are varied at a meal. OBJECTIVE: We tested the effects on intake of varying the portion size and ED of lunches served to children in their usual eating environment. DESIGN: In a crossover design, lunch was served in 3 childcare centers once a week for 6weeks to 120 children aged 3-5y. Across the 6 meals, all items were served at 3 levels of portion size (100%, 150%, or 200%) and 2 levels of ED (100% or 142%). The lunch menu had either lower-ED or higher-ED versions of chicken, macaroni and cheese, vegetables, applesauce, ketchup, and milk. Children's ratings of the foods indicated that the lower-ED and higher-ED meals were similarly well liked. RESULTS: The total weight of food and milk consumed at meals was increased by serving larger portions (P<0.0001) but was unaffected by varying the ED (P=0.22). Meal energy intake, however, was independently affected by portion size and ED (both P<0.0001). Doubling the portions increased energy intake by 24% and increasing meal ED by 42% increased energy intake by 40%. These effects combined to increase intake by 175±12kcal or 79% at the higher-ED meal with the largest portions compared to the lower-ED meal with the smallest portions. The foods contributing the most to this increase were chicken, macaroni and cheese, and applesauce. The effects of meal portion size and ED on intake were not influenced by child age or body size, but were significantly affected by parental ratings of child eating behavior. CONCLUSION: Strategically moderating the portion size and ED of foods typically consumed by children could substantially reduce their energy intake without affecting acceptability.