RESUMO
CONTEXT: Behavioral studies suggest that responses to food consumption are altered in children with obesity (OB). OBJECTIVE: To test central nervous system and peripheral hormone response by functional MRI and satiety-regulating hormone levels before and after a meal. DESIGN AND SETTING: Cross-sectional study comparing children with OB and children of healthy weight (HW) recruited from across the Puget Sound region of Washington. PARTICIPANTS: Children (9 to 11 years old; OB, n = 54; HW, n = 22), matched for age and sex. INTERVENTION AND OUTCOME MEASURES: Neural activation to images of high- and low-calorie food and objects was evaluated across a set of a priori appetite-processing regions that included the ventral and dorsal striatum, amygdala, substantia nigra/ventral tegmental area, insula, and medial orbitofrontal cortex. Premeal and postmeal hormones (insulin, peptide YY, glucagon-like peptide-1, active ghrelin) were measured. RESULTS: In response to a meal, average brain activation by high-calorie food cues vs objects in a priori regions was reduced after meals in children of HW (Z = -3.5, P < 0.0001), but not in children with OB (z = 0.28, P = 0.78) despite appropriate meal responses by gut hormones. Although premeal average brain activation by high-calorie food cues was lower in children with OB vs children of HW, postmeal activation was higher in children with OB (Z = -2.1, P = 0.04 and Z = 2.3, P = 0.02, respectively). An attenuated central response to a meal was associated with greater degree of insulin resistance. CONCLUSIONS: Our data suggest that children with OB exhibit an attenuated central, as opposed to gut hormone, response to a meal, which may predispose them to overconsumption of food or difficulty with weight loss.
