Nutrition: the Foundation of CrossFit? Yes, if you want an eating disorder. (stay with me here and read until the end :-)) What spurred me writing this post was an article (1) published in the CrossFit Journal about why nutrition is the foundation of the CrossFit program. It states things like the solution to obesity is to "get off the couch and off the carbs" and how carbs are THE cause of all these chronic diseases. While I agree that nutrition belongs on the foundation of any fitness pyramid, and getting off the couch is good for everyone, reading this article still makes me want to punch a hole in a wall. To me, it is a prime example of when someone latches onto a hypothesis, bases all their teachings and beliefs around it, then refuses to change because they've already gone all in even when it is becoming increasingly accepted and proven that the hypothesis is wrong. That is the opposite of the scientific method. It's called dogma. The evidence continues to mount. The carb-insulin hypothesis is dying. (2)(3)(4). Oh wait... we already knew that back in the 70's. (5) How much contradictory evidence does it take for someone to change their mind? I guess the CrossFit machine is pretty big now, so maybe it will take them years. Carbs alone are not the cause of the obesity epidemic or all these health issues. In fact, recent research into the underlying cause of the obesity epidemic revealed that increased calorie consumption is mostly responsible for causing the gain (seems like well, duh). But it also noted that fat, not carb consumption has increased more and is more responsible for that gain since the 1970s when obesity began to rise. (6) This review was authored by researcher Kevin Hall, the guy CrossFit's anti-carb buddy novelist, Gary Taubes, hired to do his NuSI studies attempting to prove the carb-insulin hypothesis. Kevin Hall, respected by all in his field, was the neutral party. However, those NuSI studies actually DISPROVED the insulin-obesity hypothesis and found no difference between low carb and high carb for fat loss. NuSI lost most funding and is now all but defunct. (7) Yes, certain types of carbs in excess just like certain types of fats in excess are unhealthy. But this CrossFit article is implying that carbs alone cause diabetes and high triglycerides, and that obesity doesn't play a part. Then they say carbs are the cause of obesity due to hyperinsulinemia. Yet the research is there, losing weight, even small amounts, leads to significant reduction of these issues. (8) Weight gain is caused by excessive energy intake, not insulin. And losing weight can reduce or even reverse type 2 diabetes. (9) As a side note, insulin is spiked upon consumption of protein too, but we don't often see anyone blaming whey protein powder for causing obesity. Maybe that's the next trend? So why do carbs get blamed? If you think about the label "bad carbs" or carbs that most people agree have a tendency to make us gain fat, they are: donuts, chips, fries, chocolate and candy, muffins, pastries. Not an all-inclusive list, but seems reasonable I think. These items all have one thing in common. By calorie content, they are 50% or more made up of fat. This hyperpalatable 50:50 ratio is very common in snack and restaurant foods. Our food environment has changed. It is filled with high-calorie, ultra-convenient, and ultra-delicious food designed to make us want more. Why spend 45 minutes preparing a pasta with chicken breast and veggies (~600 calories) when you can get on Uber eats and have Thai food delivered (~1200 calories) in 25 minutes? Snacks are everywhere, why stop to make lunch when you can just grab something from a bag and keep working? The average calorie consumption by Americans has gone up over 200 calories per day over the last 40-odd years. That may not sound like a lot, but that small amount can lead to 20+ lbs of fat gain per year. It is not any one macronutrient making us unhealthy as a nation. Carbs are not evil. Fat is not evil. Protein is not evil. Lack of or too much of any one macronutrient is not making us fat. It is complex, but some primary contributors to obesity are emerging and becoming more accepted: More food that is easily available and is higher calorie and lower nutrient density than in the past. Less physical activity (not gym time, think less physical jobs and transportation). More snacking and restaurants, less cooking at home. And all of this becoming the norm. The conclusion made in the recent paper by Kevin Hall was this: "It is difficult to imagine a definitive scientific demonstration of the cause of the obesity epidemic since population environmental changes are difficult to isolate and experimentally manipulate. It is easier to rule out simple explanations of obesity such as those based on individual dietary macronutrients. More plausible explanations invoke complex changes in the overall food environment and the associated alterations in normative eating behaviors. Furthermore, a confluence of multiple interrelated environmental changes apart from the food environment, such as decreased occupational physical activity, likely played important moderating roles in the development of the obesity epidemic. Disentangling the relative contributions of these environmental variables is a difficult problem, but it seems clear that the food environment is likely the primary driver of the obesity epidemic."
Don't get me wrong, I love doing CrossFit. Make fun of me for it if you want. I love the community it creates. I love how challenging it is, how technical it is, and how strong it makes me feel. It is responsible for me falling in love with exercise again and leading me to where I am today. But when it comes to Crossfit HQ's carb dogma, I simply cannot get on board. They are clinging to the past and need to update their nutrition views to match the latest science. Can following the "CrossFit Prescription" help a person get healthier or lose weight? Sure. I wholeheartedly agree that any diet with less restaurant or processed foods and more home cooking with whole foods and vegetables is a positive. I think most people can agree on that one. However, one cannot apply a one size fits all approach. The vilification of and fear they promote around carbs is literally creating disorders. I deal with it all the time when clients come to me after getting frustrated by all the confusion out there (more than half my clients are CrossFitters). Many are deathly afraid of carbs! They think if they eat a piece of bread they will get sick or get fat instantly. We spend months helping to bring them back to a place of balance, evidence-based knowledge, and empowerment. Yes, if you want, you can eat carbs and lose weight and be healthy. Even white bread and sugar *GASP*. So please, CrossFit HQ, I get it that a big part of your marketing strategy is to be polarizing, but just stop, you're not helping by pointing the finger at one supposed 'bad guy'. If you DO want to help, start by speaking with a few of the expert leaders in evidence-based nutrition, not 'best selling' sensationalist novel writers. So much good could be accomplished with your platform. Here is your nutrition expert starter pack: Alan Aragon, James Krieger, Brad Schoenfeld, Brad Dieter, Layne Norton, and Dr. Spencer Nadolsky. :-) (1) https://journal.crossfit.com/article/nutrition-saline (2) https://jamanetwork.com/journals/jama/article-abstract/2673150 (3) https://examine.com/nutrition/low-fat-vs-low-carb-for-weight-loss/ (4) https://www.cell.com/cell-metabolism/abstract/S1550-4131(15)00350-2 (5) https://www.ncbi.nlm.nih.gov/pubmed/956398 (6) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5769871/ (7) https://www.wired.com/story/how-a-dollar40-million-nutrition-science-crusade-fell-apart/ (8) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3120182/ (9) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3168743/