Why do I get sleepy after eating protein?

Only a percentage of protein is absorbed; the rest can be converted to sugar via gluconeogenesis, potentially spiking insulin and causing tiredness. Here are absorption rates:

- Breast milk: 49%

- Egg: 48%

- Meat/fish: 32%

- Wheat/soy: 18%

- Dairy: 16%

- BCAA: <1%

Excessive protein, lean protein, or protein with refined carbs can be converted to sugar. Dr. Berg recommends 3 to 6 oz of fatty protein per meal. Adjust if you're very active, large, or young. Experiment to find what works best for you.