A high-protein diet may be an effective weight-loss tool for many people, but it can also lead to long-term kidney damage among people with chronic kidney disease.

Chronic kidney disease (CKD) is structural or functional renal impairment for three or more months. The condition is generally progressive and irreversible, says nephrologist Kamyar Kalantar-Zadeh from the University of California, Irvine. High-protein diets can worsen kidney function because the body can't eliminate all of the waste products that occur when metabolizing protein.

"The high protein diet that has been used increasingly in recent years to control weight gain and obesity may have deleterious impacts on kidney health in the long term," said Kalantar-Zadeh.

The research also indicates that a low-protein diet combined with low salt, may slow the progression of CKD, as well as help manage uremia, or high levels of urea and other uremic toxins in the blood, in late-stage or advanced CKD.  A low-protein diet can help patients defer the need to initiate dialysis.

The research was published in the New England Journal of Medicine.

The Mayo Clinic says that high-protein diets usually aren't harmful if they're followed for only a short length of time. But it warns that some diets are so restrictive that nutritional deficiencies can occur, and that a lack of fiber can cause problems such as constipation, headache, and bad breath.

According to the National Institutes of Health, about 14 percent of Americans have chronic kidney disease, and more than 661,000 have kidney failure.

"There is an exceptionally high cost and burden of maintenance dialysis therapy and kidney transplantation," said Kalantar-Zadeh. "Thus, dietary interventions and nutritional therapy may be increasingly chosen as a management strategy for CKD, helping to increase longevity and delaying the need for the onset of dialysis for millions of people worldwide."