warum nehme ich zu obwohl ich wenig esse — what does this mean exactly?

The question 'Why do I gain weight even though I eat little?' reflects a common frustration and points to multiple interacting factors. First, 'eating little' is often subjective – many people underestimate their actual calorie intake or overlook hidden calories in drinks, sauces, or snacks. Beyond that, metabolic adaptation plays a key role: a reduced basal metabolic rate (due to hypothyroidism, high cortisol, or muscle loss) can cause weight gain even with moderate intake. Genetic variants like MC4R rs17782313 are associated with a small BMI increase (~0.2 kg/m² per allele) but explain less than 1% of weight variation – they are not a standalone cause. Medications (antidepressants, corticosteroids), poor sleep, chronic stress, and hormonal shifts (e.g., menopause) also alter energy balance. The evidence-based answer is: medical evaluation (thyroid, cortisol, insulin resistance) is warranted before relying on single gene tests or restrictive diets. The idea that 'eating little must lead to weight loss' is a myth – the body adapts and can lower metabolism during caloric restriction.