Family-based behavioral treatment (FBT) is the recommended treatment for children with common obesity. However, there is a large variability in short- and long-term treatment response and mechanisms for unsuccessful treatment outcomes are not fully understood. In this study, we tested if brain response to visual food cues among children with obesity before treatment predicted weight or behavioral outcomes during a 6-mo. behavioral weight management program and/or long-term maintenance.
In 37 children with obesity (age 9-11y, 62% male), brain activation was assessed at pre-treatment by functional magnetic resonance imaging across an a priori set of appetite-processing brain regions that included the ventral and dorsal striatum, medial orbitofrontal cortex, amygdala, substantia nigra/ventral tegmental area and insula in response to viewing food images before and after a standardized meal.
Children with more robust reductions in brain activation to high-calorie (vs. low-calorie) food cue images following a meal had greater declines in BMI z-score during FBT (r = 0.42, P=0.02) and greater improvements in Healthy Eating Index scores (r = -0.41, P=0.02). In whole brain analyses, our study identified the ventromedial prefrontal cortex as a region in which greater activation, specifically by high-calorie food cues (vs. low-calorie), was predictive of better treatment outcomes (P=0.02). Predictors of weight status change during follow-up were not identified nor did initial behavioral or hormonal measures predict FBT outcomes.
This study reveals that children’s brain response to a meal at obesity treatment initiation impacts their weight outcomes, implying that neurophysiologic factors and appetitive drive, more so than initial behavioral characteristics, limit intervention success.