A twin study of self-regulatory eating in early childhood: estimates of genetic and environmental influence, and measurement considerations

• Published in: International Journal of Obesity Vol. 36; no. 7; pp. 931 - 937
• Main Authors: Faith, M S, Pietrobelli, A, Heo, M, Johnson, S L, Keller, K L, Heymsfield, S B, Allison, D B
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.07.2012; Nature Publishing Group
• Subjects: 631/208/1515; 631/443/319/1488; 692/699/1702/393; 692/700/1720; Appetite Regulation - genetics; Appetite Regulation - physiology; Behavior genetics; Beverages; Biological and medical sciences; Body fat; Body Mass Index; Child; Child Nutritional Physiological Phenomena - genetics; Child Nutritional Physiological Phenomena - physiology; Child, Preschool; Children; Children & youth; Cohort Studies; Compensation; Eating - physiology; Energy; Energy Intake; Environmental factors; Epidemiology; Feeding Behavior; Female; Food; General aspects; Genetic aspects; Health Promotion and Disease Prevention; Humans; Internal Medicine; Laboratories; Male; Medical sciences; Medicine; Medicine & Public Health; Metabolic Diseases; Miscellaneous; Nutrition; Obesity; pediatric-original-article; Pediatrics; Public Health; Public health. Hygiene; Public health. Hygiene-occupational medicine; Risk factors; Sex Factors; Siblings; Twin studies; Twins; Twins, Dizygotic; Twins, Monozygotic; Waist Circumference; Weight gain; United States; United States > US; twins; compensation; pediatric obesity; self-regulatory eating; behavior genetics; heritability; Human; Obesity; Pediatrics; Feeding behavior; Estimation; Nutrition disorder; Genetic character; Self; Indemnization; Twin; Regulation(control); Food intake; Compensation; Environment; Genetics; Early; Heritability; Child; Nutritional status; Public health
• ISSN: 0307-0565; 1476-5497
• DOI: 10.1038/ijo.2011.258

Objective: Children differ greatly in their ability to self-regulate food intake for reasons that are poorly understood. This laboratory-based twin study tested the genetic and environmental contributions to self-regulatory eating and body fat in early childhood. Methods: A total of 69 4–7 year-old same-sex twin pairs, including 40 monozygotic and 29 dizygotic pairs, were studied. Self-regulatory eating was operationalized as the percentage compensation index (COMPX%), assessed by a ‘preload’ challenge in which lunch intake was measured following a low- (3 kcal) or high-calorie (159 kcal) drink. Body fat indexes also were measured. The familial association for COMPX% was estimated by an intraclass correlation, and biometric analyses estimated heritability. Results: Children ate more at lunch following the low- compared with high-energy preload ( P <0.001), although variability in COMPX% was considerable. Compensation was significantly poorer among African American and Hispanic compared with European American children, and among girls compared with boys. There was a familial association for self-regulatory eating ( ρ =0.23, P =0.03) but no significant genetic component. In all, 22% of the variance in COMPX% was due to shared environmental ‘household’ factors, with the remaining variance attributable to child-specific ‘unique’ or ‘random’ environments. Poorer self-regulatory eating was associated with greater percent body fat ( r =−0.21, P =0.04). Conclusions: Self-regulatory eating was influenced by environmental factors, especially those differing among siblings. The absence of a significant genetic effect may reflect the age of the sample or could be artifactual due to measurement issues that need to be considered in future studies.