High protein diets are thought to be a good way to lose weight, and they can be. Yet many people embrace low carb/high protein diets without being aware of the damage too much protein can do to their kidneys. Yes, cutting carbs may save calories and aid in weight loss, but a high protein diet can jeopardize your kidney function, and the changes can be irreversible.

The recommended daily protein intake for healthy adults is .8 grams per kilogram of ideal body weight (IBW) per day. Occasionally, higher intakes may be recommended for certain medical conditions, such as healing a wound, while eating less protein is often prescribed for people with chronic kidney disease (CKD).

A low carb/high protein diet is often recommended by health care professionals as a way of achieving quick weight loss or stimulating a waning appetite, but there is a cost to your kidneys to consider.

People who have diabetes, are obese, have only one kidney or are elderly are at higher risk for kidney disease. They may be unaware that they already have mild chronic kidney disease and are at risk for serious, irreversible kidney damage if they embark on a low carb/high protein diet.

The journal Nephrology Dialysis Transplantation devoted two studies and an editorial to this topic. Both studies found a connection between how much protein a person ate every day and a decline in kidney function. In one study of nearly 2,300 Dutch men aged 60 to 80 who had had a heart attack, the more protein the men ate, the faster their kidney function declined.

Men who ate more than 1.2 grams of protein per kg IBW per day (50 percent higher than the recommended .8 grams) experienced twice the decline in kidney function. Every extra intake of .1 gm/kg IBW was linked to additional decline in kidney function.

A second study of just over 9,200 South Koreans showed similar results. Those who ate a high protein diet had 1.3 higher risk of faster decline in kidney function. Researchers concluded that a high protein diet had a harmful effect on kidney function among the general population.

Whether it makes a difference if one's excess protein intake comes from animal or plant sources is not yet clear. For now, too much protein is too much protein.

“It is essential that people know there is another side to high-protein diets, and that incipient kidney disease should always be excluded before one changes [one's] eating habits and adopts a high-protein diet,” researcher, Denis Fouque, said in a statement.

The low carb/high protein diet is often recommended by physicians, dietitians and other health care professionals as a way of preventing obesity, achieving quick weight loss, stimulating a waning appetite and treating diabetes, but the cost to your kidneys may be greater than any benefits.

You can calculate your recommended protein intake in two easy steps:

  • Divide your weight in pounds by 2.2 to convertit to kilograms.

  • Multiply your weight in kilograms by .8.

    • The result is your recommended daily intake of protein in grams, and is the recommendation for healthy adults. Certain diseases may raise or lower your need for protein. Consult with your physician or a registered dietitian before changing your diet if you have a chronic disease.