Medical expert of the article
New publications
Risk of excessive protein intake
Last reviewed: 08.07.2025
All iLive content is medically reviewed or fact checked to ensure as much factual accuracy as possible.
We have strict sourcing guidelines and only link to reputable media sites, academic research institutions and, whenever possible, medically peer reviewed studies. Note that the numbers in parentheses ([1], [2], etc.) are clickable links to these studies.
If you feel that any of our content is inaccurate, out-of-date, or otherwise questionable, please select it and press Ctrl + Enter.
Eating foods high in protein poses risks to human health. Some researchers believe that the harmful effects of excess protein consumption may be exaggerated.
- Impaired renal function
A link has been established between excess protein and kidney dysfunction. Protein overload1 does create additional stress on the kidneys associated with the excretion of nitrogen, so kidney problems are possible in strength athletes, but this has not been proven. Animal studies do not support the idea that consuming large amounts of protein causes kidney problems, even if the animals are fed a high-protein diet throughout their lives. Other researchers still warn against excessive protein consumption (more than 2 g-kg per day) to avoid these problems.
- Dehydration
Excessive protein intake carries the risk of dehydration. Nitrogen excretion entails water loss, so athletes who consume large amounts of protein may be at risk of dehydration. Athletes should consume adequate fluids and monitor urine concentration, especially when consuming a high-protein diet.
- Calcium loss
It is assumed that the loss of calcium as a result of a high-protein diet increases the risk of osteoporosis. Increased dietary protein intake can cause calciuria. High-protein foods promote acid production, which is then excreted by the kidneys. Calcium is released from the bones and acts as a buffer against the increased acid load. This effect can be counteracted by the high phosphate content of mixed foods. However, the body adapts and reduces calcium loss if its intake is adequate. A calcium to protein ratio in food > 20:1 can ensure adequate protection of bone tissue.
Unbalanced diet
Excess protein poses the greatest risk when an athlete consumes inadequate amounts of carbohydrates to maintain and/or replenish muscle glycogen stores. Eating high-protein foods may limit food choices, thereby increasing the risk of vitamin and mineral deficiencies.