A high protein diet is often recommended by bodybuilders and nutritionists to help efforts to build muscle and lose fat. It should not be confused with low-carb diets such as the Atkins Diet, which are not calorie-controlled and which often contain large amounts of fat.
While adequate protein is required for building skeletal muscle and other tissues, there is ongoing debate regarding the use and necessity of high protein diets in weight training and bodybuilding. Various sources advise people to consume anywhere from 0.6 to 1.5g of protein per pound of bodyweight per day (1.4–3.3g per kg).  
Relatively little evidence has been gathered regarding the effect of protein on the development of chronic diseases. While there was initial suspicion that high-protein diets increased the risk for renal failure, studies have shown that kidney problems occur only in people with pre-existing kidney disease.  (Still, it should be noted that such problems may become apparent only when the stress of extra protein is applied to the kidneys.) Similarly, the long-held concern that it could worsen hepatic encephalopathy (brain disease due to malfunction of the liver) appears to be unfounded.
The increased load on the kidney is a result of an increase in reabsorption of NaCl. This causes a decrease in the sensitivity of tubuloglomerular feedback, which, in turn, results in an increased glomerular filtration rate. This increases pressure in glomerular capillaries. When added to any additional renal disease, this may cause permanent glomerular damage.