warum nehme ich immer mehr zu — what does this mean exactly?

The question 'Why am I gaining more and more weight?' is complex and cannot be answered with a single cause. Weight gain results from an imbalance between energy intake and expenditure, but the underlying factors are multifaceted: diet, physical activity, sleep, stress, hormones, medications, and genetics. Consumer DNA tests, such as those from MyBody-X, analyze variants in genes like FTO or MC4R that are associated with a slightly higher BMI. However, the effect sizes are small (e.g., 1–2 kg BMI difference) and not deterministic. Lifestyle factors like regular exercise can largely override these genetic influences. Microbiome tests provide only a snapshot of gut bacteria, which changes rapidly; they are not diagnostic. Importantly, no test replaces medical evaluation, especially for unexplained weight gain. The evidence for genetic predisposition is moderate (GWAS), but clinical predictive power is low. Focus should be on sustainable lifestyle changes rather than single genes.