In his new book Diet Cults, Matt Fitzgerald argues against the idea that there is any one "best" way to eat. Along the way, he covers popular diets such as Atkins, the raw-food movement, and the Paleo Diet, each time exploring the dangers of excluding an entire food group. By the end of the book, Fitzgerald replaces the dogma of dieting with a proposal he calls "agnostic healthy eating." In time for the release of his new book, we caught up with Fitzgerald to discuss what belongs on the modern athlete's plate.
OUTSIDE: What led you to write Diet Cults?
FITZGERALD: Mainstream science is on one side, saying there’s no single ideal diet for humans. But all around us, popular diets are claiming that they are the healthiest diet for all. It’s a fundamental contradiction. My gut instinct was that it was not rational to say any one diet is the best way to eat. I wanted to offer an alternative.
Why are people so passionate about diets?
Food is such a basic symbol of identity. We become emotionally invested. Even three-month-old infants show dislike for puppets who don’t like the food they like. I think we are all susceptible to the mythology that one diet is best.
Have you ever fallen for a diet cult?
Maybe supplements in some cases. I am becoming much more skeptical toward initial positive research on supplements, because if you wait long enough, some negative research comes out too.
In your book, you propose we embrace agnostic healthy eating. How do people eat like this?
They don’t demonize any nutrients. No entire food categories are eliminated. They have fruits and vegetables with almost every meal. There aren’t a lot of fried foods or sweets. It’s pretty basic stuff, but can fuel the best athletes and weekend warriors like us.
Do a lot of people already embrace agnostic healthy eating?
The silent majority of health conscious eaters out there want to eat healthy and are turned off by diet cults. In my exposure to world-class endurance athletes, very few Olympic-caliber athletes do any kind of diet with a name. They don’t demonize any nutrient. My personal instinct is that I don’t want to trust fear mongering salesmen who vilify a lot of the food people eat.
So elite endurance athletes are less likely to embrace diet cults. What about recreational athletes?
My perception is that amateur athletes are quite a bit more likely to go for diet cults. I have two theories on this. One is the sour grapes theory: That when competitive people find they can’t win races, the point of the sport switches from winning to doing it correctly. Barefoot running, Crossfit Endurance, and a lot of diets fall into that. Athletes who can win races don’t want to mess with the formula that works because a lot is at stake. The other part of it is that in today’s world, it can be hard to eat healthy. You have to swim against the stream. The diet cult does the work of how to eat healthy for you.
Diet cults tend to be trendy. That happened with the Atkins diet a decade ago, and the Paleo Diet in recent years. Are all diet cults destined to fade away eventually?
In the broader context, I believe diet cults have always been with us and always be. The Kosher eating of the Jews is a diet cult. The pleasure eating of the Food Network shows is an ongoing phenomenon. Vegetarianism has ancient pedigree. I’d guess some version of Paleo will persist because there’s something so fundamental in the idea of going back to our early paradise.
You devote a section in your book to the Paleo Diet. What’s your take on it?
The doctrine is absurd. It is a fantasy. The diet is based on a 19th-century misunderstanding that evolutionary adaptation moves at a glacial pace. The Paleo idea that no animal should eat anything it hasn’t eaten before is silly. There was the moment when chimps leapt out of trees and had to adapt their diet. Radical changes came. We started eating meat, cooking food, and traveling all over the planet. There’s also epigenetic adaptation, where genes you already have are switched on and off. Diet adaptation can happen very quickly. As for whether the diet is healthy: It can be very healthy, but the way a lot of people do it, with indiscriminate heavy meat eating, is not very healthy. I think people should eat a lot more fish and high quality meat. I see a lot of Paleo followers gobbling huge amounts of bacon.
Another chapter in your book talks about the controversy over hydrating with sugary sports drinks. What do you think about this?
People have this premise that sugar and carbs are always bad and try to explain away 50 years of research. You don’t want a lot of sugar in your diet when you aren’t exercising, but sugar is a performance enhancer. When you’re exercising, you want the fastest fuel you can get, and sugar is the highest octane stuff. I’m a big believer in fueling for performance.
A number of athletes have tried low-carb approaches in recent years. Is this diet cult effective?
If there’s any nutrient an athlete should go out of their way for, it’s carbohydrates. We know athletes in heavy training on high-carb diets are better able to absorb that training. Very few Olympic-caliber athletes mess around with this.
What about all the people who don’t care about athletic performance, but just want a diet that helps them lose weight?
I call it the suck-it-up diet. The secret to successful weight loss is motivation. Get out of the mindset of finding one way that works, and realize a lot of ways work. You still have to choose something specific. Anyone who loses weight and keeps it off doesn’t just wing it. They have rules and stick to them, but they’re not necessarily the specific rules of a diet cult.
How would you rate your own diet?
It’s much better than average. My diet looks pretty normal, but is high quality on two levels. The first is that it’s weighed heavily toward the highest quality food types, such as fruits and vegetables. I have very few fried foods and sweets, and not a lot of refined grains. I eat more fish than any other kind of meat. It’s also quality in that I buy high quality food, such as organic food, and grass fed beef, and try to pay a lot of attention to ingredient quality. But I still have at least one beer a day. My wife and I like to eat out. We celebrated my birthday on Saturday and I had French fries at a restaurant, and I almost never eat them.
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