Caution about excess protein: Many people may consume a very-high-protein diet without harm. That said, extra protein is not stored in your body for future use as protein. Instead, it’s either used as energy or stored as body fat. A high-protein diet also may be high in fat. And too much protein may displace carbohydrate foods, which are especially important for endurance sports and for weight training lasting sixty minutes or longer. Side effects may include metabolic imbalance, toxicity, nervous system disorders, and perhaps problems for those with existing kidney disease. Excess protein or amino acids can be harmful for those with unhealthy kidneys, such as those with diabetes or prediabetes.

When you consume excess protein, you need more water to excrete urea, a waste product formed when protein is broken down. So, excess protein increases the chances of dehydration as well as the need to urinate—an inconvenience during a workout.