Dietary Patterns and Health: Insights From NESR Systematic Reviews to Inform the Dietary Guidelines for Americans.

This perspective article shares unique insights from the extensive experience of the US Department of Agriculture Nutrition Evidence Systematic Review branch in conducting systematic reviews on dietary patterns and health outcomes to inform the Dietary Guidelines for Americans. Methodological approaches for reviewing dietary patterns research are described, including approaches to operationalizing definitions and analyzing labeled dietary patterns. The review also describes techniques for synthesizing dietary patterns research across life stages in systematic reviews that inform food-based, federal dietary guidance. Current research activities and recommendations for how to improve or address gaps in dietary patterns research in the future are also discussed.

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.

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.

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.

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.

Increasing flavor variety with herbs and spices improves relative vegetable intake in children who are propylthiouracil (PROP) tasters relative to nontasters.

American children do not meet the recommended daily servings of vegetables, and previous research suggests children who can taste the bitterness of 6-n-propylthiouracil (PROP) are more likely to have low vegetable intake. This study tested the hypothesis that adding multiple herb and spice blends to vegetables to increase flavor variety within a meal would increase vegetable intake in 3-5year-old children. Children attended two laboratory visits and consumed two test meals of common foods: macaroni and cheese, applesauce, carrots, milk, and water. On one visit, the meal included three servings of carrots with different herb and spice blends (Variety condition). On the other visit, all three servings of carrots were seasoned with the same herb and spice blend (No Variety condition). Overall, children consumed similar amounts of carrots by condition (36.5±40.5g versus 35.9±43.8g at the Variety and No Variety conditions, respectively); however, this relationship was moderated by PROP status. Children who tasted PROP as bitter (tasters) consumed a greater proportion of carrots during the Variety condition relative to nontasters (p=0.03). These findings suggest that children who taste PROP as bitter may be more receptive than nontasters to manipulations that increase flavor-variety of vegetables using herbs and spices.