Response to Energy Dilution in the Short Term: Evidence of Nutritional Wisdom in Young Children?

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 (β = -0.38; P = 0.008). Sex (β = 0.11; P = 0.76), age (β = 0.03; P = 0.75), and weight (assessed continuously; β = -0.07, P = 0.37) were not related to compensation. Children with overweight/obesity (assessed categorically) undercompensated more than children with healthy weight (β = 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.

Calorie Compensation and Self-Regulation of Food Intake in College Students

OBJECTIVE

To examine self-regulation of food intake among college students.

DESIGN

Randomized cross-over study completed between September and November, 2019.

SETTING

A large public university, Florida International University in South Florida.

PARTICIPANTS

A total of 60 undergraduate college students, mean age of 19.8 ± 1.43 years old, 62% female, 74% Hispanic, 76% White.

INTERVENTION(S)

Participants attended 2 trials 1 week apart. During each visit, students were offered a preload drink (either 0 or 210 kcal) followed by a buffet-style lunch. Food intake was estimated using weights and pictures of the plates before and after eating and was compared between the 2 sessions.

MAIN OUTCOME MEASURE(S)

Self-regulation by calculating compensation indices (COMPX) and their correlation with students' body mass index (BMI).

ANALYSIS

Intake differences were examined using Welch and t tests. Regression analysis was used to assess correlations.

RESULTS

Students exhibited the ability to calorie compensate when intake is manipulated with a mean COMPX of 95.57 ± 71.19. No score was perfect. There was a significant correlation between BMI and COMPX scores (F = 10.71, P < 0.001, r² = 0.292). Food choices differed between different BMI categories.

CONCLUSIONS AND IMPLICATIONS

Participants showed some degree of self-regulation, which suggests opportunities for creating effective interventions to improve health status and promote a more sustainable method to control consumption among college students.

How Much and What: Using a Buffet to Determine Self-regulation of Food Intake Among Young School-Age Children

Energy compensation indices are commonly used to examine self-regulation of food intake in children. However, previous studies failed to consider children's ability to self-regulate under complete autonomy. This study examined self-regulation of food intake among young children and the effect of calorie manipulation on food/nutrient intake using an unlimited lunch buffet paradigm. Participants were 66 children (M^age = 6.14, SD = 1.15 years; 68.2% male; 89.4% Latinx; 59.1% overweight/obese [OV/OB]). Children participated in a crossover research trial, one week apart. Participants consumed 2 different types of preloads followed by an ad-libitum lunch during each trial. A compensation index (COMPX) was calculated to identify the level of self-regulation in food intake. Food/nutrient intake was compared between both sessions. Results indicated OV/OB children showed poorer self-regulation compared to healthy weight children (t=2.19, p = .032; Hedges' g = 0.55). There were significant differences in food intake/selection between OV/OB and healthy weight groups. OV/OB children consumed a higher amount of calorie, fat, and cholesterol after the high energy preload compared to healthy weight children (d's range: 0.31-0.48). Our findings support differences between the amount of self-regulation between normal and OV/OB children as well as the items they select in order to compensate.

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.

Effects of Unsweetened Preloads and Preloads Sweetened with Caloric or Low-/No-Calorie Sweeteners on Subsequent Energy Intakes: A Systematic Review and Meta-Analysis of Controlled Human Intervention Studies

Effects of isocaloric (sweetness differences but constant calories) preloads and isosweet (caloric differences but constant sweetness) preloads, as well as preloads that were neither isosweet nor isocaloric (sweetness and caloric differences) on subsequent ad libitum meal and total (preload + ad libitum) energy intakes were investigated. Thirty-five crossover studies were eligible for inclusion, representing 116 comparisons (41, isocaloric; 41, isosweet; and 34, neither isosweet nor isocaloric). References of existing reviews and literature from 4 databases were searched. The calculated raw mean differences in ad libitum and total energy intakes were pooled in meta-analyses using a random-effects model and the inverse of the variance as the weighting factor. Energy intakes at an ad libitum meal were significantly lower for low-/no-calorie sweetener (LNCS)-sweetened compared with unsweetened preloads in the isocaloric comparison (-55.5 kcal; 95% CI: -82.9, -28.0 kcal; P < 0.001); however, the difference in energy intake was not significant in additional sensitivity analyses (i.e., removal of comparisons where the matrix was a capsule and when xylitol was the LNCS). For the isosweet comparison, although the pooled energy intake at the ad libitum meal was significantly greater with the LNCS-sweetened preload compared with the caloric sweetener (CS)-sweetened preload (58.5 kcal; 95% CI: 35.4, 81.7 kcal; P < 0.001), the pattern was reversed when total energy intake was considered (-132.4 kcal; 95% CI: -163.2, -101.6 kcal; P < 0.001), explained by only partial compensation from the CS-sweetened preload. The results were similar when assessing ad libitum and total energy intakes when unsweetened compared with CS-sweetened preloads were consumed. Unsweetened or LNCS-sweetened preloads appear to have similar effects on intakes when compared with one another or with CS-sweetened preloads. These findings suggest that LNCS-sweetened foods and beverages are viable alternatives to CS-sweetened foods and beverages to manage short-term energy intake.

Observed behavioral indicators of child satiation at mealtime: Associations with child characteristics and parent-reported child eating behaviors

The notion of promoting parents' recognition of child satiation to reduce overfeeding and overeating in children is prevalent. To do so, it is important to identify common behaviors that may indicate satiation and can be easily recognized by parents. Relatively little work has focused on identifying behaviors that may indicate child satiation as they occur during naturalistic mealtimes, which is an important context for parents to observe their children's eating behavior. Hence, the goal of the current study is to examine whether observed behavioral indicators of child satiation at mealtimes are associated with child characteristics (i.e., sex, age, and BMIz) and parent-reported child appetitive traits. We coded observed behaviors thought to indicate satiation, specifically mealtime disengagement and mealtime negativity, in a cohort of 240 families with children between 4- and 8-years old (53% boys). First, we documented the occurrence of child disengagement and negativity during naturalistic mealtimes. Second, we found that lower child BMIz and being a boy were associated with greater mealtime disengagement, but child age was not associated with mealtime disengagement. No associations were found between child characteristics and mealtime negativity. Third, we found that mealtime disengagement and mealtime negativity were associated with mother-reported satiety responsiveness on the Child Eating Behavior Questionnaire. Taken together, our findings suggest observed mealtime disengagement and mealtime negativity behaviors could be helpful indicators of child satiation in a naturalistic mealtime context.

11 and 15-month-old infants do not compensate immediately for energy variation, and no further adjustment occurs 12 or 24 hours later

Previously, we demonstrated that, in the short term, infants undercompensated for the energy from a preload given 25 min before an ad libitum meal. However, although not consistent, there is evidence in young children that caloric adjustment may occur over longer periods. We investigated the extent to which further energy adjustment occurs up to 24 h after a single meal preceded by preloads of varying energy density (ED) in infants that are 11 and 15 months old. Short-term caloric adjustment was measured in 11- and 15-month-old infants through a preload paradigm meal in the laboratory. To assess their caloric adjustment over longer periods (12 and 24 h), we used 24 h dietary records to evaluate the energy intake (EI) after each visit to the laboratory. Three COMPX scores were calculated according to three different time periods after preload consumption (0 h [i.e., short-term], 12 h or 24 h). Our main result was that, on average, regardless of the time period considered, the infants undercompensated their EI after preload consumption: at 11 and 15 months, caloric adjustment was partial and similar overtime. Considering that a slight repeated imbalance of the energy balance may promote rapid weight gain over the first months, this study calls for further research focusing on facilitators and barriers of efficient appetite control abilities in infancy.

Appetite self-regulation declines across childhood while general self-regulation improves: A narrative review of the origins and development of appetite self-regulation

This narrative review discusses the origins and development of appetite self-regulation (ASR) in childhood (from infancy to age 6 or 7 years). The origins, or foundations, are the biological infrastructure associated with appetite regulation and appetite self-regulation. Homeostatic regulation in infancy is examined and then evidence about developmental change in components of ASR. The main ASR-related components covered are: delay-of-gratification, caloric compensation, eating in the absence of hunger, food responsiveness/hedonics and fussy eating. The research included behavioral measures, parent-reports of appetitive traits and fMRI studies. There were two main trends in the evidence: a decline across childhood in the components of ASR associated with food approach (and therefore an increase in disinhibited eating), and wide individual differences. The decline in ASR contrasts with general self-regulation (GSR) where the evidence is of an improvement across childhood. For many children, bottom-up automatic reactive processes via food reward/hedonics or food avoidance as in fussy eating, appear not to be matched by improvements in top-down regulatory capacities. The prominence of bottom-up processes in ASR could be the main factor in possible differences in developmental paths for GSR and ASR. GSR research is situated in developmental science with its focus on developmental processes, theory and methodology. In contrast, the development of ASR at present does not have a strong developmental tradition to access and there is no unifying model of ASR and its development. We concluded (1) outside of mean-level or normative changes in the components of ASR, individual differences are prominent, and (2) there is a need to formulate models of developmental change in ASR together with appropriate measurement, research designs and data analysis strategies.

Development and preliminary testing of a technology-enhanced intervention to improve energy intake regulation in children

Interventions designed to improve children's self-regulation of energy intake have yielded mixed results. We tested the efficacy of a technology-enhanced intervention designed to teach children to eat in response to internal hunger and fullness cues. Thirty-two children (mean age 4.9 ± 0.8 y) completed this within-subjects, pre-post design study that took place across 10 laboratory sessions, each scheduled approximately 1 week apart. The intervention was conducted across weeks 4-7 in small groups focused on teaching children how food travels through the body and how to respond to hunger and fullness signals. Children's short-term energy compensation, a measure of intake regulation, was collected at baseline and follow-up using a preloading protocol. Twenty-five minutes prior to receiving a standardized test meal, children consumed a low-energy (3 kcal) or high-energy (150 kcal) preload beverage, presented in random order at baseline and follow-up. Knowledge of intervention concepts was also assessed at baseline and follow-up. Linear mixed models were used to examine changes in short-term energy compensation and knowledge from baseline to follow-up. Knowledge related to the intervention improved from baseline to follow-up (3.5 ± 0.3 to 7.0 ± 0.3 correct responses out of a possible 10; P < 0.001). Children's energy compensation also improved from baseline to follow-up, as evidenced by a time-by-preload condition interaction (P = 0.02). However, this improvement was driven by boys who increased the adjustment for beverage energy content from baseline to follow-up (P = 0.04). Girls showed no change in energy compensation with the intervention (P = 0.58). The overall increase in knowledge, paired with the improvement in energy compensation in boys, suggests that this technology-enhanced intervention may be efficacious for some children. Further research is needed to determine whether boys and girls will benefit from different, personalized intervention strategies for obesity prevention.

Maternal Decisions on Portion Size and Portion Control Strategies for Snacks in Preschool Children

Caregivers are responsible for the type and amount of food young children are served. However, it remains unclear what considerations caregivers make when serving snacks to children. The aim of the study was to explore mothers' decisions and portion control strategies during snack preparation in the home environment. Forty mothers of children aged 24-48 months participated in the study. Mothers prepared five snack foods for themselves and their child whilst verbalizing their actions and thoughts. Mothers were then asked about their portion size decisions in a semi-structured interview. Transcripts were imported into NVivo and analyzed thematically. Three key themes were identified: (1) portion size considerations, (2) portion control methods, and (3) awareness and use of portion size recommendations. Transient, food-related situational influences influenced mothers and disrupted planning and portion control. Food packaging and dishware size were used as visual cues for portion control; however, these vary widely in their size, thus emphasizing mothers' uncertainty regarding appropriate portion sizes. Mothers called for portion size information to be accessible, child-centered, and simple. These findings reveal multiple considerations when deciding on the correct snack portion sizes for children. These decisions are complex and vary across situations and time, and according to the types of snacks offered.

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 ± 2%), but serving higher-ED foods increased energy intake by 84 ± 16 kcal/d (to 105 ± 2% of needs) and serving lower-ED foods decreased energy intake by 72 ± 17 kcal/d (to 89 ± 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.

Caloric compensation in infants: developmental changes around the age of 1 year and associations with anthropometric measurements up to 2 years

BACKGROUND

Previous results based on dietary recall suggest that the ability to adjust eaten quantities to food energy density (ED) may deteriorate around the age of 1 y. However, this hypothesis has not been investigated experimentally.

OBJECTIVES

The first aim of the study was to describe changes in the short-term caloric compensation ability of infants around the age of 1 y. We expected a decrease in this ability with age. The second aim was to identify individual factors [e.g., breastfeeding duration, body mass index (BMI) z-score, and change in BMI z-score] related to interindividual variations in caloric compensation ability.

METHODS

We adapted the preload paradigm to calculate a COMPX score. The measure was performed in the laboratory at 11 and 15 mo. The parent offered a food preload that was either low or high in ED (LED = 33 kcal/100 g or HED = 97.9 kcal/100 g, respectively), followed by an ad libitum meal after 25 min. The infants were measured and weighed. Information about the infants' milk-feeding history was collected.

RESULTS

We obtained COMPX scores at 11 and 15 mo for 31 infants (12 females). As hypothesized, the caloric compensation ability significantly decreased with age (COMPX11 = 52% ± 133%; COMPX15 = -14% ± 151%; P = 0.03). The more the COMPX score decreased, the more the BMI z-score between 11 and 15 mo increased (P = 0.03) and the higher the BMI z-score was at 2 y (P = 0.03). No associations were found between COMPX scores and breastfeeding duration (all P > 0.60).

CONCLUSIONS

Caloric compensation ability decreases between 11 and 15 mo. This decrease is associated with a larger increase in weight status from 11 to 15 mo and a higher weight status at 2 y. This study calls for further research to better understand the early determinants of caloric compensation ability. This trial was registered at www.clinicaltrials.gov as NCT03409042 (https://clinicaltrials.gov/ct2/show/NCT03409042).

A Biopsychosocial Model of Sex Differences in Children's Eating Behaviors

The prevalence of obesity and eating disorders varies by sex, but the extent to which sex influences eating behaviors, especially in childhood, has received less attention. The purpose of this paper is to critically discuss the literature on sex differences in eating behavior in children and present new findings supporting the role of sex in child appetitive traits and neural responses to food cues. In children, the literature shows sex differences in food acceptance, food intake, appetitive traits, eating-related compensation, and eating speed. New analyses demonstrate that sex interacts with child weight status to differentially influence appetitive traits. Further, results from neuroimaging suggest that obesity in female children is positively related to neural reactivity to higher-energy-dense food cues in regions involved with contextual processing and object recognition, while the opposite was found in males. In addition to differences in how the brain processes information about food, other factors that may contribute to sex differences include parental feeding practices, societal emphasis on dieting, and peer influences. Future studies are needed to confirm these findings, as they may have implications for the development of effective intervention programs to improve dietary behaviors and prevent obesity.

The impact of stopping high-energy oral nutritional supplements on eating behaviour and weight gain

BACKGROUND AND AIMS

Many children referred to a tertiary feeding clinic are already taking high-energy oral nutritional supplements (HEOS), but these often seem not clinically useful. We undertook a retrospective review of all children on HEOS at the time of referral to the clinic in order to describe their subsequent progress in terms of growth and feeding behaviour.

RESULTS

A total of 48 children were on HEOS at referral and withdrawal of HEOS was attempted in 38 children, aged median 3.0 years (range 0.7-10 years) who were taking volumes equivalent to 2/3 of total daily energy requirements. The children tended to be very short and slim (median height SD score (SDS) -2.0 (range -5.7 to 1.9); body mass index -2.0 (-5.1 to 1.9)). Half had normal neurodevelopment (ND) but 4 (11%) had learning disability and 4 (11%) severe ND problems. By last follow-up after 0.86 (0-2.9) years, 30 (79%) had stopped all feeds. Those who stopped had a mean (SD) change in weight of 0.08 (0.6) SDS (range -0.88 to +1.59). Five children (17%) showed significant catch-up weight gain after stopping feeds, of whom three had been referred for weight faltering and possible tube feeding. Improvement in feeding behaviour was documented in 76% (29).

CONCLUSIONS

The use of HEOS in children suppresses appetite for solid food due to energy compensation. In some cases, HEOS may perpetuate or even cause weight faltering. It should not be assumed that failure to respond to HEOS is an indication for tube feeding.

Does low-energy sweetener consumption affect energy intake and body weight? A systematic review, including meta-analyses, of the evidence from human and animal studies

By reducing energy density, low-energy sweeteners (LES) might be expected to reduce energy intake (EI) and body weight (BW). To assess the totality of the evidence testing the null hypothesis that LES exposure (versus sugars or unsweetened alternatives) has no effect on EI or BW, we conducted a systematic review of relevant studies in animals and humans consuming LES with ad libitum access to food energy. In 62 of 90 animal studies exposure to LES did not affect or decreased BW. Of 28 reporting increased BW, 19 compared LES with glucose exposure using a specific ‘learning' paradigm. Twelve prospective cohort studies in humans reported inconsistent associations between LES use and body mass index (−0.002 kg m⁻² per year, 95% confidence interval (CI) −0.009 to 0.005). Meta-analysis of short-term randomized controlled trials (129 comparisons) showed reduced total EI for LES versus sugar-sweetened food or beverage consumption before an ad libitum meal (−94 kcal, 95% CI −122 to −66), with no difference versus water (−2 kcal, 95% CI −30 to 26). This was consistent with EI results from sustained intervention randomized controlled trials (10 comparisons). Meta-analysis of sustained intervention randomized controlled trials (4 weeks to 40 months) showed that consumption of LES versus sugar led to relatively reduced BW (nine comparisons; −1.35 kg, 95% CI –2.28 to −0.42), and a similar relative reduction in BW versus water (three comparisons; −1.24 kg, 95% CI –2.22 to −0.26). Most animal studies did not mimic LES consumption by humans, and reverse causation may influence the results of prospective cohort studies. The preponderance of evidence from all human randomized controlled trials indicates that LES do not increase EI or BW, whether compared with caloric or non-caloric (for example, water) control conditions. Overall, the balance of evidence indicates that use of LES in place of sugar, in children and adults, leads to reduced EI and BW, and possibly also when compared with water.

Childhood obesity and eating behaviour

The prevalence of childhood obesity has increased substantially in the recent decade as a result of the reduction in physical activity and the availability of high-fat and high-energy-density foods which the paediatric population faces daily. Although children are highly exposed to these foods, there is a wide variation in body weight, suggesting the presence of different patterns of response to an "obesogenic" environment. This wide variability from the point of view of eating behaviour involves a number of social issues (e.g., food availability, cost) as well as genuine behavioural traits such as the response to satiety, energy compensation, eating rate, responsiveness to food, food reward and dietary preferences. This article reviews the main physiological variables related to energy intake affecting eating behaviour in the paediatric population.

Energy compensation in enterally fed children

Limited exposure to solid food in early childhood may affect the development of appetite regulation. We used formal satiation studies to assess energy compensation in children who have been artificially fed. Subjects were 11 children, median age 4.5 years (range 1-10) who were formerly (n=4) or currently (n=5) mainly tube fed or supplement fed (n=2), with a range of surgical or neurodevelopmental problems. On 2 separate days a high-energy preload (HEP) and low-energy preload (LEP) drink were given followed by a multi-item test lunch. A compensation index (COMPX) score was derived as follows: COMPX (%)=[(Meal(lep)-Meal(hep))/(Preload(hep)-Preload(lep))]× 100. The median (range) COMPX of the participants was 70% (-73% to 178%). The 8 boys tended to compensate more (median 99%) than the 3 girls (30%; P Mann-Whitney=0.1), but there was no clear association of compensation with age. Although a small preliminary study, this suggests that children who have been artificially fed demonstrate energy compensation comparable to that of normally fed children.

Plenary Lecture 1: Dietary strategies for the prevention and treatment of obesity

Obesity is a rapidly-growing public health problem that is related in part to the foods available in the eating environment. Properties of foods such as portion size and energy density (kJ/g) have robust effects on energy intake; large portions of energy-dense foods promote excess consumption and this effect starts in early childhood. Studies show, however, that in both adults and children these food characteristics can also be used strategically to moderate energy intake, as well as to improve diet quality. Dietary energy density can be reduced by increasing intake of water-rich foods such as vegetables and fruits. Their high water content allows individuals to eat satisfying portions of food while decreasing energy intake. Filling up at the start of a meal with vegetables or fruit and increasing the proportion of vegetables in a main course have been found to control hunger and moderate energy intake. Data from several clinical trials have also demonstrated that reducing dietary energy density by the addition of water-rich foods is associated with substantial weight loss even though participants eat greater amounts of food. Population-based assessments indicate that beginning in childhood there is a relationship between consuming large portions of energy-dense foods and obesity. These data suggest that the promotion of diets that are reduced in energy density should be an important component of future efforts to both prevent and treat obesity.

The relationship between dietary energy density and energy intake

Much of the research in ingestive behavior has focused on the macronutrient composition of foods; however, these studies are incomplete, or could be misleading, if they do not consider the energy density (ED) of the diet under investigation. Lowering the ED (kcal/g) by increasing the volume of preloads without changing macronutrient content can enhance satiety and reduce subsequent energy intake at a meal. Ad libitum intake or satiation has also been shown to be influenced by ED when the proportions of macronutrients are constant. Since people tend to eat a consistent weight of food, when the ED of the available foods is reduced, energy intake is reduced. The effects of ED have been seen in adults of different weight status, sex, and behavioral characteristics, as well as in 3- to 5-year-old children. The mechanisms underlying the response to variations in ED are not yet well understood and data from controlled studies lasting more than several days are limited. However, both population-based studies and long-term clinical trials indicate that the effects of dietary ED can be persistent. Several clinical trials have shown that reducing the ED of the diet by the addition of water-rich foods such as fruits and vegetables was associated with substantial weight loss even when patients were not told to restrict calories. Since lowering dietary energy density could provide effective strategies for the prevention and treatment of obesity, there is a need for more studies of mechanisms underlying the effect and ways to apply these findings.

Variants of the peroxisome proliferator-activated receptor gamma- and beta-adrenergic receptor genes are associated with measures of compensatory eating behaviors in young children

BACKGROUND

Young children can regulate energy precisely in the short term, showing the potential for an innate compensation mechanism of eating behavior. However, data suggest that precise compensation is attenuated as a function of increasing adiposity, parental feeding style, and age. Common variation in candidate obesity genes may account for some of the individual variation observed in short-term energy compensation. Polymorphisms in the peroxisome proliferator-activated receptor gamma (PPARG) and beta-adrenergic receptor (ADRB3) genes have been linked to increased body mass index (BMI; in kg/m(2)), obesity, and more recently dietary nutrients and preferences. In addition, common variation in ADRB3 interacts with PPARG to modulate adult body weight.

OBJECTIVE

This study investigated whether variants in these genes were associated with measurable effects on child eating behavior.

DESIGN

Children (n=84) aged 4-10 y were prospectively selected for variants of the PPARG locus (Pro12Ala, C1431T). Heights and weights were measured. Energy intake from a test meal was measured 90 min after ingestion of a no-energy (NE), low-energy (LE), or high-energy (HE) preload, and the compensation index (COMPX) was calculated.

RESULTS

BMI differed significantly by gene model, whereby Pro12Ala was associated with a lower BMI. Poor COMPX was associated with the PPARG T1431 allele (P=0.009). There was a significant interaction between COMPX and the ADRB3 Trp64Arg variant in modulating compensation (P=0.003), whereas the Arg64 allele was associated with good compensation (P=0.001).

CONCLUSIONS

This is the first study to suggest that a genetic interaction involving ADRB3 and PPARG variants influences eating behavior in children.

Energy intakes of children after preloads: adjustment, not compensation

BACKGROUND

Young children accurately compensate for energy-dense preloads consumed before test meals. The accuracy of compensation seems to deteriorate as a function of age.

OBJECTIVE

The hypothesis that accurate energy compensation varies by age, body mass index, and individual characteristics of children and their mothers was tested.

DESIGN

Energy intake (EI) from a test meal was measured in 74 children aged 6-9 y 90 min after the ingestion of no-energy (NE), low-energy (LE), or high-energy (HE) preload snacks. The NE preload consisted of 250 mL water, the LE preload consisted of a 56-g muffin + a 250-mL orange drink (783 kJ), and the HE preload consisted of a 56-g muffin + a 250-mL orange drink (1628 kJ).

RESULTS

A significant dose-related reduction in EI was found after the preloads; younger children adjusted more effectively than did older children, although total EI (including preload energy) indicated that the adjustment was not accurate. The compensation index (COMPX) differed by preload and age group; COMPX scores were higher between the NE and LE preloads (younger children: 44.4 +/- 9.3%; older children: 57.0 +/- 11.6%) than between the NE and HE preloads (39.6 +/- 4.9%; 31.3 +/- 6.2%) and the LE and HE preloads (35.2 +/- 7.8%; 7.4 +/- 9.8%). This finding indicates a more consistent response across preloads and a greater sensitivity to energy load by younger than by older children. High interindividual variation and low intraindividual variation in COMPX was found. The tendency to over- or undereat in response to the preloads (deviation from perfect) correlated directly and positively with maternal concerns about child overweight, not with actual BMI.

CONCLUSIONS

The children adjusted their EIs in response to different preloads, and the younger children did so more effectively than did the older children. Poor short-term energy compensation may constitute a behavioral marker for positive energy balance.