Athletes looking to build muscle mass and overweight people looking to drop a few pounds on a low carbohydrate diet often consume larger-than-normal amounts of protein. Some medical practitioners worry about the effect of large amounts of protein on the kidneys. Many recommend drinking extra fluids, especially water, if you're following a high protein diet. In large amounts, even water can be harmful, so speak with your medical practitioner about your fluid requirements before starting a high-protein diet.
High Protein Doses
A person on an average 2,000 calorie diet needs around 60 g of protein per day, The Merck Manuals Online Medical Library states. While following the Atkins Diet, which recommends a low carbohydrate intake and an increase in protein and fats, The Physician's Committee for Responsible Medicine found that dieters took in between 120 and 143 g of protein per day, or double the recommended dose.
When athletes consume more protein without increasing water or other fluid intake, their BUN -- or blood urea nitrogen level, which measures kidney function -- rises, Janice Palmer explains in the University of Connecticut's April 29, 2002, issue of "Advance." This occurs because of the extra stress placed on the kidney while eliminating the breakdown by-products of protein, which isn't used as efficiently by your body as carbohydrate for energy. High protein intake causes the kidneys to produce more concentrated urine, the University of Connecticut, a sign of dehydration caused by the extra fluid needed to eliminate the waste products.
Types and Amounts
Even a small decrease in hydration, 2 percent, can affect your body's ability to function, including your heart, the University of Connecticut states. People on high-protein diets need to drink more than the 8 to 10 glasses of water recommended for healthy adults. Fluids that contain caffeine, such as coffee and tea, don't help increase hydration levels because they act as diuretics.
Increasing water intake may also help avoid another potential complication of high protein intake: kidney stones. The American Academy of Family Physicians feels that the increased dietary protein intake in the United States causes most kidney stone formation.
Drinking too much water can do more than send you scrambling for a bathroom -- it can kill you. Drinking too much at one time can cause low sodium levels, or hyponatremia. Symptoms of hyponatremia include headache, nausea, fatigue, loss of appetite and mental changes such as confusion or hallucinations. Signs of hyponatremia require immediate medical attention.