Tosca Reno’s arms have been sculpted by kale seasoned with unprocessed sea salt. NOT.

According to certain “experts” in the fitness industry, fat loss is primarily based on nutritional choices. Exercise has little or no impact on body composition. The “Eat Clean Queen” Tosca Reno quantifies such claims, declaring that working out has an effect on the body of only 10%, with genetics providing another 10%, and food intake adding up to 80%. In other words: you are exactly what you eat, so stop blaming your genes. And stop worrying about working out, apparently. I call bullshit on these invented statistics and what they imply.

First let me admit that nutrition is usually the primary factor in weight gain or loss. There are other reasons, seemingly glossed over by some experts, including the impact or lack of specific hormones, sleeping habits, and medical conditions. All the same, the quantity and quality of what you eat is the main reason you look (and perhaps feel) the way you do. Being lean requires almost continual attention to meal planning. Tosca Reno is right to highlight the importance of eating in efforts to shape health and body weight. She is right to recommend eating six small, balanced meals composed of unprocessed, organic vegetables, meats or other sources of protein, and whole grains. And she is right to advise portion control. Admittedly, Reno goes a bit overboard with discussions of “Frankenfoods” and her hatred of foods with more than five ingredients or chemicals. Guess what, almost all foods have many ingredients—like my homemade chili, for example—and contain chemicals. Corn flakes are not exactly the devil, though John Harvey Kellogg’s enema cures were potentially inspired by Satan. I digress. Even fresh peppers are filled with chemical compounds and yet they shockingly remain healthy. Words matter and generalizations are rarely correct even though they sell books that can be read in less than one hour.

Some of the stuff in peppers.

I take umbrage, however, at the suggestion that exercise has little impact on body weight or composition. But I have to be careful here. Because it seems like some people think that exercise has a massive and immediate effect on body composition. They try Jillian Michael’s 30 day shred and wonder why they have not lost any weight. It takes far more than 30 days to get into shape. Gaining muscle is hard, especially for most women. And the people following such a regime might gain muscle by working out faithfully, thereby causing the number on the scale remain the same or increase, even as their overall percentage of body fat decreases. Exercise is not a magic bullet for weight loss. But it is magic! It is awesome. And it cannot be reduced to a number like “10%” in discussions of weight loss and fitness.

Exercise teaches people about their bodies and what their bodies can do. It can make people appreciate, love and care for their bodies. Here I am obviously not talking about the methods promoted by Jillian Michaels and her ilk. I am referring to any kind of exercise that is pleasurable or otherwise rewarding to the person doing it. I recommend training with someone who is educated and has experience, like Fitbabe. I worked out with Fitbabe at her studio the other day, and I loved it. She made me do a range of movements and functional weight training that had me sweating buckets, while feeling great and socializing. Yesterday I walked 30 minutes to her studio, trained with her and another awesome friend for an hour, then walked back downtown to teach a spin class before walking home. It was the best day of my week! Still, my personal experiences might not be very convincing with regard to the purpose of exercise.

There is plenty of scientific evidence supporting the value of exercise, for mental and physical health, maintenance of bone density while ageing and so on. I will not bother repeating it here. At the same time, it is clear that exercise helps to attain and maintain healthy weight loss. [Aside: weight loss can be healthy even as it is not in itself a very motivating or rewarding goal. Wanting to lose weight is not in and of itself “bad.” It is not a sign of conformity and feminist failure. All the same, I want to stress the importance of maintenance here, instead of focusing on constant improvement. Maintenance is less sexy but it is indeed a worthy accomplishment.] For the greatest impact, exercise should be strenuous, preferably occurring every day, and include resistance training. But any form of exercise at almost any level will have a positive overall effect on weight and health. Various studies show that people who exercise are more apt to stay on a diet plan. Others show that certain forms of exercise—i.e. lifting heavy things—can elicit a positive hormonal response, increasing testosterone and growth hormones that can increase muscle mass while decreasing visceral belly fat. Exercise furthermore increases life expectancy, regardless of the person’s overall body weight. Fuck 10%.

I cannot comment online, however, about the claim that genetics counts for only 10% of body weight or composition. I am not very knowledgeable about genetic history or theory and therefore have few opinions to offer. Imagine that.