Weight gain is associated with changes in neural response to palatable food tastes varying in sugar and fat and palatable food images: a repeated-measures fMRI study

Abstract

Emerging data suggest that weight gain is associated with changes in neural response to palatable food tastes and palatable food cues, which may serve to maintain overeating. We investigated whether weight gain is associated with neural changes in response to tastes of milkshakes varying in fat and sugar content and palatable food images. We compared changes in neural activity between initially healthy-weight adolescents who gained weight (n=36) and those showing weight stability (n=31) over 2-3 y. Adolescents who gained weight compared with those who remained weight stable showed decreases in activation in the postcentral gyrus, prefrontal cortex, insula, and anterior cingulate cortex, and increases in activation in the parietal lobe, posterior cingulate cortex, and inferior frontal gyrus in response to a high-fat/low-sugar compared with low-fat/low-sugar milkshake. Weight gainers also showed greater decreases in activation in the anterior insula and lateral orbitofrontal cortex in response to a high-fat/high-sugar compared with low-fat/low-sugar milkshake than those who remained weight stable. No group differences emerged in response to a low-fat/high-sugar compared with a low-fat/low-sugar milkshake. Weight gainers compared with those who remained weight stable showed greater decreases in activation in the middle temporal gyrus and increases in cuneus activation in response to appetizing compared with unappetizing food pictures. The significant interactions were partially driven by group differences in baseline responsivity and by opposite changes in neural activation in adolescents who remained weight stable. Data suggest that weight gain is associated with a decrease in responsivity of regions associated with taste and reward processing to palatable high-fat- and high-fat/high-sugar food tastes. Data also suggest that avoiding weight gain increases taste sensitivity, which may prevent future excessive weight gain.This trial was registered at clinicaltrials.gov as NCT01949636.