What role does FTO play in Müdigkeit?

FTO (Fat Mass and Obesity-associated) is a gene primarily linked to body weight, fat mass, and appetite regulation. Variants in FTO (e.g., rs9939609) are among the most robustly replicated genetic risk factors for obesity. The connection to fatigue is indirect and less well established. Some studies suggest that FTO variants may influence energy expenditure or mitochondrial function, potentially affecting subjective feelings of tiredness. However, effect sizes are small and evidence is mixed. Fatigue is multifactorial – sleep quality, stress, hormones, nutritional status, and psychological factors play a larger role. A genetic test for FTO alone cannot determine fatigue. Consumer DNA tests like those from MyBody-X provide risk indications, not diagnoses. Anyone experiencing persistent fatigue should seek medical evaluation, including thyroid function, iron status, vitamin D, and cortisol diurnal profile. The evidence for a direct FTO-fatigue link is graded as 'mixed/unclear'.