There’s a guy out there right now flogging a diet book, who, along with a few poignant anecdotes, points to scientific studies which show that foods that cause your blood sugar to spike lead to more organ fat. The one and only thing you need to do to be healthy is eat more veggies and nuts, and avoid sugar and white flour.
Another diet says (pretty much) if you eat a lot of fat, your body will learn to burn fat.
There are plenty of other diets that show that fewer carbs, or less fat, or whatever, will lead you to the better life you’ve been craving. Each of those diets will claim to be based on science, and delve into insulin, glucose, neurotransmitters, and so on.
Each diet says there’s ONE THING you have to do to be healthy. Well, mainly one thing, but it doesn’t hurt to adopt other healthy habits as well.
Some of the diets are downright contradictory, but they all claim to have science on their side. How can this be?
There’s something remarkably cool going on, right now: In the last fifteen years we’ve learned a lot of really interesting stuff about how the body responds to the food we eat and even the mechanisms that make us feel hungry in the first place. If nutrition and health is a puzzle, we are finally getting to understand what shape the pieces are. It is conceivable that in a couple more decades we’ll have a pretty good look at what the puzzle actually looks like.
In the meantime, folks with medical degrees are choosing individual pieces of that puzzle and they are selling them as a complete answer. They’re not wrong, really, but they are absolutely overselling the facts. Activity X leads to hormone Y and therefore you get fat.
A scientific survey of the experiments testing the diets, which, alas, I can no longer find the link to, discovered an interesting thread: All the diets, when carefully followed, were beneficial, and none of the diets was clearly better than any of the others.
In the end, it came down to the same thing your mother told you when you were a kid: eat more veggies, and get more exercise. You just didn’t know at the time that you mother was that far ahead of science.
The one thing you can do to be healthier? Listen to your mother.