Still More Vindication for the Low Carb/High Protein Diet

No, it won't "kill your kidneys"

Anyone who has tried a high-protein diet has probably heard this warning: You may lose weight, but you risk kidney damage. The idea is that processing large amounts of protein strains your kidneys, which filter blood and remove waste. But there is little research backing that assertion.

In one study, in The International Journal of Sport Nutrition and Exercise Metabolism, researchers recruited bodybuilders and other athletes, then examined their kidney function over seven days as they followed high- and medium-protein diets. The researchers found that every marker of kidney function was within the normal range in all of the athletes who consumed large amounts of protein.

In a much larger study, published in The Annals of Internal Medicine, researchers looked at protein intake in 1,624 women over an 11-year period. They found that high-protein diets did not cause any problems in women with normal kidney function. But in women who had “mild renal insufficiency,” they wrote, consuming large amounts of protein accelerated renal decline. University of Connecticut researchers reached a similar conclusion when they reviewed years of research on the subject in a 2005 report in the journal Nutrition & Metabolism.

I've never given any credence to that particular claim (although I've heard it numerous times).  For one thing, in most cases a "high protein diet" is high in protein compared to a "normal" diet because carbohydrates (sugars and starches) have been drastically reduced, and not because because the calories taken in as protein are dramatically increased.  This is what leads to the weight loss.  I also firmly believe, and have experienced the fact that a diet low in carbohydrates leads to a greater feelings of satiety and less hunger between meals, and makes it easier to eat a diet with fewer total calories.

For such a diet to cause kidney damage would require you to presuppose that the presence of carbohydrates has some "buffering" reaction that prevents kidney damage at similar protein concentrations.

We've been on the a carbohydrate diet since Jan. 1, and as of today, I am down 33 lbs and Georgia is down 20, with no evidence of kidney problems.