I recently read the book Diet Cults, by Matt Fitzgerald. It’s about how the nutritional science behind various diets (such as vegan diets, gluten-free diets) isn’t sound. The author exposes the incorrect principles on which many of these diets are based. He also suggests his own version of a healthy diet, justified by science, which he describes as the sort of diet that athletes use to maximise their performance. It’s an entertaining book: an easy read, and I learnt a lot. He doesn’t go deeply into the science (so I was left with a number of unanswered questions). Here are some parts of the text that stuck with me.
I’ll begin with a quote.
… there is no such thing as the healthiest diet. To the contrary, science has established quite definitely that humans are able to thrive equally well on a variety of diets. Adaptability is the hallmark of man as eater. For us, many diets are good while none is perfect.
He makes this point beautifully in the text, with wonderful examples. Some are geared to a US audience, but it doesn’t matter. Roughly speaking, the split of carbohydrate/fat/protein (the sources of calories) varies across different, but equally healthy, populations in the world. Humans adapt.
The author suggests looking to athletes for dietary guidance because these people have sought out the best diet to improve their performance, which is also the healthiest diet for all of us.
What elite endurance athletes truly desire is the least restrictive diet that is sufficient to yield maximum fitness and performance. And they’ve found it.
I like this point, although it was stated a little strongly for my liking; they think they’ve found the best diet, but future research may prove them wrong in parts.
Here’s another quote.
What our history does show us is that, despite the messages we receive from the many contending preachers of the One True Way, there are numerous dietary pathways to optimal health. Ironically, it is this very breadth of options that makes it possible for the various health-diet cults to produce good results that support the illusion of their superiority.
As you can see, he writes well. One of the diets he talks about is the raw-food diet. The raw-food group claim that we should eat in the same way as early humans. Fitzgerald argues cooking actually made us human. Cooking increases the energy yield of foods by making them more digestible. This high level of energy allowed us to evolve big brains.
Other dieters state that we should try to eat the same foods as early humans. The author quotes the biomolecular archeologist Christina Warinner who explains that nearly every food that our Paleolithic ancestors ate no longer exists today, and that virtually every food humans eat today is different from those eaten by our Paleolithic ancestors.
He dedicates a whole chapter to potatoes, about how healthy they are. He cites various people who have lived for a long time on potatoes and little else. Of course, potatoes can be turned into unhealthy foods, such as crisps.
He has a chapter on exercise too, and generally writes a good deal about exercise throughout. There is widespread belief these days that to lose weight you should eat better, but exercising will not help. The reason it won’t help, as I understand it, is because after exercise you eat more, so you regain the calories you’ve burned off. This seems like a ridiculous argument to me: weight comes from consumption of calories minus the calories you use up. To reduce weight you can either reduce the number of calories coming in (eat better) or increase the amount of calories you use up (by exercising, say). Now, whether or not you eat more after exercising is another matter, which depends on how you’ve exercised, who you are, and what you normally eat. The fact is that exercising uses up calories, so to suggest that it doesn’t help in weight loss is peculiar. The book says similar types of things, although doesn’t argue quite as I have done.
After the exercise chapter there is one on coffee, dark chocolate, and alcohol: how these are good for you in moderation. Well, this was news to me. I occasionally glance at studies in the newspapers suggesting that these foods can be healthy, but I ignore them. I’ll have to look into this more carefully. There isn’t much scientific justification in the book.
Later on I read that sports drinks (sugar + water) are effective if drunk before sport: studies have shown that they improve performance. He writes
Nowadays, though, anti-sugar prejudice has left many athletes unable to wrap their heads around the idea that sugar could ever be beneficial in any context.
I found the chapter after the sugar water chapter the least satisfying in the book. It was about fasting. It talked about the benefits of fasting for much of the chapter, but then right at the end stated (without justification) that you don’t need to fast to achieve optimum levels of health. Ellie and I have started fasting recently, for a variety of reasons. Partly to help us appreciate food more, partly so that we can experience and cope with hunger (in a small way), and partly because of the health benefits.
Getting towards the end of the book now, Fitzgerald says the mind and the body are deeply interconnected. He was writing about how your state of mind can affect your health as much as food can (so it’s very hard to, say, give two people the same diet and expect the same results). He discussed stress in particular. Reduce stress and improve your health!
At the end of the book the author offers his dietary plan. He categorises foods into ten types, in the following order.
- nuts, seeds, and healthy oils
- high-quality meats and seafood
- whole grains
- refined grains
- low-quality meats and seafood
- fried foods
His plan is that you should eat more of 1 than 2, more of 2 than 3, and so forth. (He explains it more precisely than that.) He isn’t dogmatic about the whole thing, and he himself eats foods towards the bottom of the list, but not much. I think it’s a useful, simple guide, and it has helped encourage me to eat better. I currently have too much of 9. Today that came in the form of two waffles. I’ve skipped dinner.
To conclude, it’s an enjoyable and informative book.