High-fat, low carb diets such as the Paleo and ketogenic plans are being increasingly embraced by elite athletes.
A notable example is NBA superstar LeBron James, who made headlines this week after unveiling his shocking 25-pound weight loss on a low carb ketogenic-style diet.
The 6-foot-8 James, who weighed 250 pounds last season, looks dramatically thinner after adoping a strict low carb diet. While LeBron was not overweight, sources said the dramatic weight loss was motivated by James' desire to ease pressure on his joints, especially his knees.
James, 29, was also inspired by the health transformation of his former Miami Heat teammate, Ray Allen, who said he experienced improved energy and better post-workout recovery after switching to the low-carb, sugar-free Paleo diet in 2013. At 39, Allen remains in top shape at an age when most basketball stars are retired.
While carb-loading is deeply ingrained in endurance sports, a growing number of long-distance runners, cyclists and triathletes are also embracing the low-carb, high-fat Paleo and ketogenic diets.
Tim Noakes, a professor of exercise and sports science at the University of Cape Town in South Africa, said low-carb, high-fat diets promote weight loss, combat diabetes and reduce inflammation.
Noakes said once athletes get fat-adapted (meaning their body learns to burn fat instead of glucose for fuel), they will experience better performance in the long haul. “For events of more than five hours, fat-adapted athletes have an advantage,” he said.
The Paleo diet is already popular among professional athletes and celebrities. It has been adopted by the Los Angeles Lakers (including superstar Kobe Bryant), Miami Heat guard Ray Allen, and Houston rockets center Dwight Howard.
Similarly, pro cyclist Dave Zabriskie and ultra-marathoner Timothy Olson abandoned their high-carb, low-fat eating plans in favor of the high-fat, lower-carb Paleo diet, and experienced meaningful performance gains.
Olson told Runner's World his post-workout recovery improved after going Paleo. Olson set a new course record at the Western States 100-mile endurance run in 2012, a few months after going Paleo. "My legs are less swollen after really long runs," said Timothy. "I can go hard again sooner than I did before I went Paleo."
Nutrition experts say the Paleo diet's emphasis on healthy fats helps the body shift from burning carbs for fuel to burning fat. Research indicates the Paleo diet accelerates weight loss, reduces blood pressure, and prevents diabetes, heart disease, Alzheimer's and cancer.
Joe Friel, a U.S. Olympic triathlon coach, said the Paleo diet works for triathletes because it helps with recovery. “[Paleo offers] better long-term recovery due to greater micronutrient content [than a standard high-starch, high-sugar diet], allowing the athlete to train with a greater stress load,” said Friel.
Friel said the Paleo menu provides more antioxidants and vitamins than the typical high-carb diet favored by most endurance athletes and boosts fat oxidation and weight loss — a major advantage for endurance athletes, because the less excess weight you carry, the faster you'll be.
Ironman Triathletes Adopt Low-Carb Ketogenic Diet
Another interesting trend is the growing use of the high-fat, low-carb ketogenic diet among triathletes. Fitness expert Ben Greenfield trained for the 2013 Ironman Triathlon World Championships in Kona, Hawaii by following the high-fat ketogenic diet and completed the epic endurance race in a blistering 9:59:26.
Ben, author of "Beyond Training," detailed his ketogenic diet experiment on a podcast. Greenfield's breakfast the morning of the Ironman was a half-stick of butter, two shots of MCT oil, and a cup of coffee — a stark contrast to the heaping plates of pasta most endurance athletes inhale before a race. Greenfield no longer follows the ketogenic diet, but encourages the consumption of healthy fats.
Similarly, Dr. Jay Lehr, a 78-year-old triathlete, said he has followed a low-carb, high-fat ketogenic-style diet his entire life and credits it for his excellent health. Jay has thrived on a diet of red meat, saturated fat, dairy, eggs, butter, and lard and has never felt better.
“I’ve never been inside a regular doctor’s office,” said Lehr. “I have lived my entire life on high fat — dairy, eggs, butter and lard.” Jay recently completed his 13th Ironman triathlon.