Relation of FTO to BOLD response to receipt and anticipated receipt of food and monetary reward, food images, and weight gain in healthy weight adolescents

Abstract

Although the fat mass and obesity-associated gene (FTO) correlates with elevated body mass, it is unclear how it contributes to overeating. We tested if individuals with the A allele show greater reward region responsivity to receipt and anticipated receipt of food and money and palatable food images. We also tested if these individuals show greater future weight gain. Initially healthy weight adolescents (Study 1, N = 162; Study 2, N = 135) completed different functional magnetic resonance imaging paradigms and had their body mass measured annually over 3 years. Adolescents with the AA or AT genotypes showed less precuneus and superior parietal lobe response and greater cuneus and prefrontal cortex response to milkshake receipt and less putamen response to anticipated milkshake receipt than those with the TT genotype in separate analyses of each sample. Groups did not differ in response to palatable food images, and receipt and anticipated receipt of money, or in weight gain over 3-year follow-up. Results suggest that initially healthy weight adolescents with vs without the FTO A allele show differential responsivity to receipt and anticipated receipt of food but do not differ in neural response to palatable food images and monetary reward and do not show greater future weight gain.

Keywords: FTO gene; BOLD response; adolescents; prospective; weight gain.

Fig. 1. Sample timing of (A) the block milkshake receipt paradigm and (B) the food picture paradigm.

Fig. 2. Significant group-by-cue interactions in BOLD signal in (A) right putamen (Montreal Neurological Institute, MNI coordinates: 24, 21, −3; Z = 3.90; k = 61) in response to the contrast milkshake cue > tasteless solution cue and (B) cuneus (MNI coordinates: −6, −78, 12; Z = 3.10; k = 35) in response to the contrast milkshake receipt > tasteless solution receipt in Study 1.

Fig. 3. Significant group-by-cue interactions in BOLD signal in the precuneus (MNI coordinates: 27, −66, 33; Z = 3.34; k = 44) in response to the contrast low-fat/low-sugar milkshake receipt > tasteless solution receipt in Study 2.