welche stoffwechseltypen gibt es — when to see a doctor?

The concept of 'metabolic types' (e.g., ectomorph, mesomorph, endomorph) is popular in fitness culture but lacks robust scientific validation. These categories originated from 1940s somatotyping and do not reliably predict how your body processes carbohydrates, fats, or proteins. Commercial DNA tests claiming to identify your 'metabolic type' often rely on weak associations with genes like PPARG, FTO, or UCP1, and are not clinically validated. Evidence for such typing is mixed at best and largely marketing-driven. You should see a doctor if you experience unexplained weight changes, persistent fatigue, cold intolerance, palpitations, or digestive issues. A physician can check thyroid function, blood glucose, and liver markers. Do not rely on direct-to-consumer tests for diagnosis; seek professional medical evaluation.