A great deal of the food advice you hear is based on the assumption that there is one way of eating that is best for everyone. This “one diet” assumption is wrong for reasons that I will explain here. A slight variation on this approach asks you to determine the best thing for you to eat based on your body composition or your genetically determined biochemical tendencies. This at least recognizes that not everyone has to eat the exact same things, but it is subject to the same shortcomings as the “one diet” approach.
The problem with the “one diet” idea is immediately evident if you imagine 7 billion people all switching to the same food choices simultaneously. If you accept the premise, for the sake of discussion, that the ideal diet prominently features avocados and mushrooms, there simply aren’t enough avocados and mushrooms for everyone in the world to have some. The world’s avocado production is about 5 million tons, enough to provide 2 avocados per person — per year. Mushroom production is similar in magnitude, enough for each of us to eat about one mushroom every four days. If our diets depended on avocados and mushrooms, or any combination of “ideal” foods we might choose, we would all go hungry.
And in fact, a quarter of the world does go hungry at some point during a typical week. About one person every three seconds dies of starvation, and for these people, any discussion of an “ideal diet” is missing the point. You can only eat what you can get. And the same considerations apply to nearly all of us in varying degrees. Depending on where you are and what resources you have, some food items are easier to get than others.
Personally, I am a big fan of pumpkin as a food. Pumpkins grow within walking distance of where I live, so I have a near-ideal experience as a purchaser of pumpkins. I pay hardly anything for a big, heavy pumpkin, and it is as fresh as can be. In other regions, people may have the same experience with a different crop — pineapples, peppers, or rice, perhaps. If you live among pineapple fields, it is probably hard to imagine that a pineapple could cost as much as a pumpkin, but that is what I find here.
Of course, it is not just a question of your local agriculture. The money you have to spend, your access to food distribution, and your cooking abilities all play into your food choices, along with many other factors.
Some experts cite ideas of human history to support their “one diet” proposals, and this too is a mistake. The actual story of food in human history is that the people and nations that adapted to the food that was available to them were the ones that were most successful. There is no story of an ancient tribe that scoured the world searching for the ideal diet. What records we have of successful primal diets show a wide variation between one climate and another.
Some of the “ideal” diets that I have heard about would have a person spending $35 a day on food, or more. That is millionaire territory — $35 a day adds up to $1 million in a lifetime. And it is, in my opinion, unnecessary. Most of us, if we have kitchens to work in, still have plenty of ways we can improve the food we eat by spending less money. If we want to upgrade our diets, we may as well start there.