Study shows link between FTO, ghrelin and impaired brain food-cue responsivity

Individuals carrying the "obesity-risk" allele of the fat mass and obesity associated gene, FTO, are prone to obesity and obesity related eating behaviors such as increased food consumption, preference for high fat foods and lack of satiation after eating. How this particular gene regulates obesity prone behaviors is not fully understood.

In this issue of the Journal of Clinical Investigation, Rachel Batterham and colleagues at University College London identify a link between FTO and the hunger-stimulating hormone, ghrelin. Subjects homozygous for the "obesity-risk" allele of FTO had higher concentrations of circulating ghrelin after eating, which correlated with an absence of satiation. They demonstrate that FTO directly demethylates ghrelin mRNA, altering its production. These studies offer new insight into why individuals that carry the "obesity-risk" allele of the FTO gene are prone to obesity.