High-protein hype?

Men's Fitness, March, 2003

I'm considering going on a high-protein diet to promote muscle growth, but I hear that can be hard on your kidneys. True or false?

--TOMMY HUANG, SUSANVILLE, CA

"A high-protein diet doesn't have to be extreme--as long as you also include healthy fats and some carbohydrates," says Charles Hensley, who has a doctorate in physiology and is the chief executive officer of PRB Pharmaceuticals. "Still, this type of diet does place additional demands on the kidneys. Any time you have proteins in the blood, it makes more work for the kidneys to filter them out." But that's not necessarily harmful. "It's really just excess work more than anything else," Hensley says.

This approach does necessitate some accommodations in your diet, however. "You should drink more water when you're on a high-protein diet," Hensley says. The standard recommendation for the general public is eight 8-ounce glasses of water a day. Guys on high-protein diets should include an extra 32 ounces to help process the extra protein, and those working out regularly should include another additional 32 ounces. Don't worry; it's not as hard as it sounds.

"Once you boost your protein intake, your thirst will most likely increase," Hensley explains. "Whenever you have an increase in protein, it has a diuretic effect on your cells--fluid moves from the cells into the bloodstream, triggering the hormones which signal the body that you need to drink more fluid."

A healthy person's risk of developing kidney problems from a high-protein diet is overstated. "People who get into trouble with high protein are those who have kidney problems to begin with," Hensley says. "As long as your kidneys are healthy and you drink plenty of water, a high-protein diet should pose no problems."