Although pharmacotherapy has established utility in bulimia nervosa and BED, further research on medications for the treatment of eating disorders, particularly anorexia nervosa, is necessary.

Objective: Genetic variation in the first intron of FTO (e.g., single-nucleotide polymorphism [SNP] rs9939609) is strongly associated with adiposity. This effect is thought to be mediated (at least in part) via increasing caloric intake, although the precise molecular genetic mechanisms are not fully understood. Prior pediatric studies of FTO have included youth with overweight and obesity; however, they have not informed whether a genotypic effect on ingestive behavior is present prior to obesity onset. Therefore, this study investigated the association between FTO and caloric intake in children aged 5 to 10 years without obesity (adiposity ≤ 95th percentile). Methods: A total of 122 children were genotyped for rs9939609 and ate ad libitum from a laboratory lunch buffet following a standardized breakfast. Linear regressions, adjusting for body mass, were used to examine the association between FTO "dose" (number of copies of SNP rs9939609) and intake variables. Results: There was a significant association between FTO and total intake. Each risk allele predicted an additional 64 calories, accounting for 3% of the variance. There were no associations between FTO and macronutrient preference, energy density, or diet variety. Results were influenced by race. Conclusions: Results corroborate and extend prior work by showing a dose-dependent effect on food intake in children without obesity.

Objective: Noncoding alleles of the fat mass and obesity-associated (FTO) gene have been associated with obesity risk, yet the underlying mechanisms remain unknown. Risk allele carriers show alterations in brain structure and function, but previous studies have not disassociated the effects of genotype from those of body mass index (BMI). Methods: Differences in brain structure and function were examined in children without obesity grouped by their number of copies (0,1,2) of the FTO obesity-risk single-nucleotide polymorphism (SNP) rs1421085. One hundred five 5-to 10-yearolds (5th-95th percentile body fat) were eligible to participate. Usable scans were obtained from 93 participants (15 CC [homozygous risk], 31 CT [heterozygous] and 47 TT [homozygous low risk]). Results: Homozygous C allele carriers (CCs) showed greater grey matter volume in the cerebellum and temporal fusiform gyrus. CCs also demonstrated increased bilateral cerebellar white matter fibre density and increased resting-state functional connectivity between the bilateral cerebellum and regions in the frontotemporal cortices. Conclusions: This is the first study to examine brain structure and function related to FTO alleles in young children not yet manifesting obesity. This study lends support to the notion that the cerebellum may be involved in FTO-related risk for obesity, yet replication and further longitudinal study are required.

Pediatric obesity is a major public health concern. Genetic susceptibility and increased availability of energy-dense food are known risk factors for obesity. However, the extent to which these factors jointly bias behavior and neural circuitry towards increased adiposity in children remains unclear. While undergoing fMRI, 108 children (ages 5-11y) performed a food-specific go/no-go task. Participants were instructed to either respond (“go”) or inhibit responding (“no-go”) to images of food or toys. Half of the runs depicted high-calorie foods (e.g., pizza) whereas the other half depicted low-calorie foods (e.g., salad). Children were also genotyped for a DNA polymorphism associated with energy intake and obesity (FTO rs9939609) to examine the influence of obesity risk on behavioral and brain responses to food. Participants demonstrated differences in behavioral sensitivity to high- and low-calorie food images depending on task demands. Participants were slower but more accurate at detecting high- (relative to low-) calorie foods when responding to a neutral stimulus (i.e., toys) and worse at detecting toys when responding to high-calorie foods. Inhibition failures were accompanied by salience network activity (anterior insula, dorsal anterior cingulate cortex), which was driven by false alarms to food images. Children at a greater genetic risk for obesity (dose-dependent model of the FTO genotype) demonstrated pronounced brain and behavioral relationships such that genetic risk was associated with heightened sensitivity to high-calorie food images and increased anterior insula activity. These findings suggest that high-calorie foods may be particularly salient to children at risk for developing eating habits that promote obesity.