Caloric compensation and eating in the absence of hunger in 5-to 12-y-old weight-discordant siblings

Background: An impaired ability to compensate for calories and increased eating in the absence of hunger (EAR) has been associated with increased energy intake and weight gain in unrelated children. Objective: The aims of this study were to compare caloric compensation [the percentage compensation index (%COMPX)] and EAH in weight-discordant siblings aged 5-12 y. Design: In a crossover, behavioral genetics design, 47 same-sex sibling pairs (53% female, 55% full siblings) were served dinner once a week for 3 wk. Across conditions, siblings were served the same dinner, but 25 min before dinner, they either consumed in full or did not consume 1 of 2 preloads that varied in energy density (ED; 0.57 or 0.97 kcal/g). On the day when no preload was consumed, EAH was assessed after dinner and defined as the number of calories consumed from snacks. Results: Overweight/obese siblings undercompensated [%COMPX: -48.8 +/- 56.3 (mean +/- SEM)] and therefore overate after the high-ED preload, whereas normal-weight siblings showed accurate compensation (%COMPX: 101.3 +/- 51.9; P = 0.03). Furthermore, overweight/obese siblings consumed 34% more calories (93 kcal) in the absence of hunger than did normal-weight siblings (P = 0.01). Within-pair resemblances for %COMPX and EAH were stronger for full siblings (P < 0.049) than for half siblings (P > 0.23). Conclusions: An impaired ability to regulate short-term energy intake, which includes incomplete adjustment for calorie differences in a preload and eating when satiated, may represent a behavioral phenotype for obesity in children. Future studies should test whether teaching children to focus on internal satiety cues may prevent at-risk children from overeating. This trial was registered at clinicaltrials.gov as NCT01598389. Am J Clin Nutr 2012;96:574-83.