McCormack’s weight-loss success story is inspiring—but far from unique. McCormack is among the legions of CrossFitters who follow Paleo’s back-to-basics, evolutionary approach to eating. It’s the nutritional approach for about 90 to 95% of affiliates, estimates Robb Wolf, author of The Paleo Solution and former CrossFit nutrition advisor. (Related: Does CrossFit Live Up to the Hype?) Many affiliates host their own Paleo competitions, and the eating style is constantly a hot topic of discussion on CrossFit message boards.
The widespread adoption of a diet within a fitness community is something of a phenomenon. After all, it’s not as if all yogis are vegetarians, or all Spin junkies are on the South Beach diet. So then what accounts for this almost cultist adoption of an eating plan in an already cultish fitness subgroup?
The Beginning of a Movement
CrossFit headquarters originally pushed the Zone diet, which advocates a specific ratio of carbs, protein, and fats, and works best when food is weighed and measured. (Search: Should I try the Zone diet?) But soon, Wolf began covering Paleo in his CrossFit nutrition seminars, and its popularity in the community spread like wildfire. (Wolf’s own come-to-Paleo moment happened when it cured his Ulcerative Colitis.) Whereas the Zone adherents exactingly measure out their food, the Paleo lifestyle doesn’t explicitly regulate portion size at all. In other words, it’s a lot easier to follow.
Eventually, Wolf had a public falling out with CrossFit headquarters, which he attributes in part because of his adamant stance on the superiority of eating Paleo. In any case, Paleo has emerged as the de facto diet among CrossFit die-hards.
Paleo for Performance
If the CrossFit-Paleo connection was inspired by Wolf, it spread because it actually delivers results. And although measurable gains are always a win, CrossFitters place a particular emphasis on them. “CrossFit is very focused on performance metrics. They want their athletes to be measurably stronger, faster, and fitter,” says former affiliate owner Melissa Hartwig, founder of Whole9 and the Whole30 programs and author of It Starts with Food (June 2012). Within 30 days of switching to the Paleo lifestyle, she had added 10 pounds to her jerk, 15 pounds to her clean, and shaved off 5 minutes from her 5-K.
“I haven’t been sick in three years,” echoes Amy Ferro, co-owner of CrossFit Southie in Boston. “My performance has gone up. My body fat is lower. And I’m also stronger. It’s worked for so many people in our community that it’s hard to not believe in it.”
“It’s a kind of a self-fulfilling diet,” explains Loren Cordain, PhD, co-author of The Paleo Diet for Athletes. “You feel better and perform better.” The reasoning: Muscle growth is stimulated by branch chain amino acids, and lean proteins are a good source of them while grains are a poor one. On the Paleo diet, you’re essentially eliminating grains and eating more meat, so you’re getting more muscle-building protein. Plus, a 2009 study in the European Journal of Clinical Nutrition found that the diet may improve blood pressure, increase good cholesterol, and help you lose weight.
The Hive Mind
The almost universal adoption of Paleo also occurred in part because CrossFit started small. “CrossFit had a very concentrated group of people who were really engaged,” says David “Chef” Wallach, dietician, chef and owner of CrossFit Rubicon. “There were limited sources on the Web, so information wasn’t scattershot.” As a result, and CrossFitters turned towards people like founder Greg Glassman and Robb Wolf, as well as the CrossFit Journal.
Moreover, the Paleo diet appealed to the almost tribal mentality of CrossFit.
“Does CrossFit have a cult-y feel?” asks Wolf. “Yes, but that is kind of normal. If something is really popular, you’re going to have an in and out crowd. And you get that in the Paleo scene too.”
“CrossFitters consider themselves a little countercultural,” adds Hartwig. “It’s not your typical exercise methodology and in the same way Paleo isn’t your typical diet.”