wie viel eiweiß brauche ich — when to see a doctor?

The question about optimal protein intake and when to see a doctor cannot be answered from the provided context, which only covers alcohol flushing (ALDH2/ADH1B), weight loss, and a single SNP (rs10246939) with no clinical significance. In general medical practice, the recommended dietary allowance (RDA) for protein is 0.8 g per kg of body weight for healthy adults. Athletes, older adults, or those recovering from illness may need 1.2–2.0 g/kg. A doctor should be consulted if you have pre-existing kidney or liver disease, unexplained weight loss, persistent fatigue, muscle weakness, or if a high-protein diet causes nausea or joint pain. Also seek medical advice if lab tests show elevated urea or creatinine, which may indicate kidney strain. These are standard guidelines, but the evidence is not derived from the provided context.