Myths vs facts: FTO and Sport

The FTO gene (e.g., rs9939609) is one of the most studied loci for obesity risk. Myth: 'The FTO gene makes you fat no matter what you do.' Fact: The risk variant increases the likelihood of higher BMI, but the effect is modest (about 0.4 kg/m² per risk allele) and is modifiable by lifestyle. Regular physical activity can attenuate the genetic predisposition. Myth: 'FTO determines my athletic performance.' Fact: There is no robust evidence that FTO directly affects endurance, strength, or sprint ability. Associations with sport are mostly through BMI and body fat, not performance metrics. Some studies suggest an interaction with appetite regulation, but evidence is inconsistent. The provided context documents contain no specific studies on FTO and sport; the statements are based on general knowledge from GWAS and meta-analyses. Caution: Direct-to-consumer tests marketing FTO as a 'sport gene' are overhyped. For athletes, the utility of FTO genetics is low; training and nutrition are far more impactful.