If a diet promised to help you lose weight, feel energized, and dodge colds and flu, would you try it? What if you had to give up pasta, bagels, and oatmeal? Carbs may be staples for many runners, but they are one of the restrictions in the Paleo diet, which advocates a model of eating based on prehistoric humans' diets. A growing number of runners have joined its ranks. But is it good for you?
"Paleo has a lot of very good things going for it," says Heather Mangieri, M.S., R.D., spokesperson for the Academy of Nutrition and Dietetics. The program excludes processed foods and refined sugars and emphasizes vegetables, fruits, nuts, and grass-fed meat. All good. "We know diets rich in fruits and vegetables fight heart disease and certain cancers," says Mangieri.
Grass-fed meat has a healthier fat ratio than grain-fed, and all meat provides amino acids that speed recovery. A few months after adopting a Paleo diet, ultrarunner Timothy Olson set a new course record at the 2012 Western States 100-Mile Endurance Run. "My legs are less swollen after really long runs," says Olson. "I can go hard again sooner than I did before I went Paleo."
But the Paleo diet also eliminates grains and legumes (both key carb sources for runners), as well as dairy, alcohol, salt, and vegetable oils. Paleo protagonists, such as researcher Loren Cordain, Ph.D., coauthor of The Paleo Diet for Athletes, say that these foods raise your body's acid levels and leach minerals from your bones. Cordain cites substances within those foods (phytates in whole grains and lectins in beans) that inhibit nutrient absorption.
But Mangieri disagrees: "Nutrient loss is minimal," she says, "and it doesn't seem to cause deficiencies." She points to Mediterranean populations that enjoy long life and little chronic disease with a diet rich in grains and legumes. (See what a day of eating like cavemen is really like, here.)