How to Decide What to Eat

by Craig Good
June 17, 2025

Organic. Natural. Processed. Ultra-processed. Synthetic. GMO- or gluten-free. Whole. Clean. These words seem to latch onto our food and can cause a lot of stress. My first advice to you is to just relax. Except sometimes for gluten-free, which genuinely does matter to people with celiac, what those words have in common is that they're used in fear-based marketing. You may simply ignore them. Marketing campaigns that use these terms are just trying to frighten you into buying their product. These terms don't really mean anything useful.

Let's back up a minute and get down to basics. What is food, anyway? It's something you ingest which gives you some combination of these seven basic things:

• Carbohydrates
• Protein
• Fats
• Hydration, a fancy word for what water gives you
• Vitamins
• Minerals
• Fiber

That's pretty much it. Nothing exotic. The first three, carbs, proteins, and fats, are what you need most of, and where you get your calories, so they're called macronutrients. Vitamins and minerals are chemicals your body needs in small quantities, and which it can't synthesize on its own. They're called micronutrients. Fiber is an interesting one. It doesn't feed you directly, but your gut microbiome feeds on it, and it performs a few other functions outside the scope of this episode. So now that you know what food is, you still want to know what you should eat.

While nutrition science is enormously complicated, the question of what to eat is astonishingly simple. That's assuming that you live a life where you actually have a choice of what to eat. If that's you, count your blessings. Before we continue with any advice, please understand that this is intended for typically healthy people who do have the privilege of choosing their diets. There are allergies, intolerances, and conditions, such as celiac (which I mentioned before) which may need to influence your choices. Follow the instructions of your qualified medical practitioners rather than anything you hear in a podcast, even this one.

Here is about the most specific advice anybody can give you: Enjoy a variety of foods, mostly plants, including plenty of fruits and vegetables, not too much or too little. If you hear advice much more specific than that, it's likely that someone is trying to sell you something. The key word here is variety. We evolved to thrive on a variety of foods. So what you really want to do is think in terms of diet, not individual foods.

Here's a good way to think of it: What you eat today doesn't matter, but what you eat this month does. In fact, if you're reasonably healthy, it doesn't even matter if you eat today. So don't waste time trying to decide which food is healthy and which isn't, because any food can be part of a healthy diet.

Yes, that means that there are no unhealthy foods. There are unhealthy diets, but no unhealthy foods. There are no superfoods, no fattening foods, and no such thing as junk food. All food is processed, so there's no reason to demonize food for being processed or, as in the latest fad, "ultra-processed". Nobody can even define what ultra-processed means.

For example, there's nothing wrong with sugar. But you can have serious problems if added sugar forms too big a portion of your diet. Ditto for salt, fat, or any other ingredient you can name, even water. Lately the fad ingredients to demonize are seed oils. Know what's wrong with seed oils? Not a thing. In fact, there's research associating many of them, including plain old canola oil, with good health outcomes.

Speaking of demonizing food, let's talk about where not to get nutrition advice. You can safely ignore advice from anybody who is trying to frighten you away from a food or ingredient. Fear-based marketing is so common because it works. Except after this episode it won't work so well on you, meaning you'll save money as well as be healthier. Also, don't take advice from someone whose website has a shopping cart. I'm not talking about merch like on Skeptoid's site, but supplements or so-called "wellness" products.

While we're talking about fear, heed this important warning: If you have any "fear foods", or experience any anxiety around food, please see a doctor immediately. Eating disorders are the deadliest of all mental illnesses, and by a wide margin. If you have any concerns at all, start with a visit to your doctor, who can recommend appropriate resources.

Surely we can use science to guide our food choices, right? Right, but with an important caveat. Don't use the "latest study" to make health decisions. A single study can be a fascinating and important part of advancing science, and we often celebrate those here in the weekly Skeptoid companion email in a feature called Wonder of the Week. But — and this is important — you shouldn't modify your diet based on a single study. Instead seek out the scientific consensus. That's what you get when there's a lot of solid evidence all pointing in the same direction.

For example, there's a consensus that you should minimize the trans fats in your diet, and that added sugars shouldn't exceed about 5% of your average daily caloric intake. By the way, for most people that translates to roughly 25 grams of added sugar. That might motivate you to switch to zero-calorie soft drinks which are, you guessed it, safe. There's also a strong consensus that the less alcohol you consume the better off you are. Earlier studies showing benefits for small amounts of alcohol turned out not to be very high quality.

Unless your qualified medical practitioner has specifically recommended one, you don't need any kind of dietary supplements. Yes, that includes vitamin supplements. If you live in an industrialized society and eat a good variety of fruits, veggies, and other foods, you're probably getting all the macronutrients and micronutrients that you need. By qualified medical practitioner I mean science-based medical doctors and registered dietitians. This specifically excludes so-called functional medicine, naturopaths, chiropractors, homeopaths, and pretty much anybody who uses "holistic" or "wellness" in their title.

It's worth noting that, at least in the U.S., the supplement industry is essentially unregulated. What you're buying is frequently an unknown dose of an untested ingredient along with an unknown amount of contaminants. That's if the ingredient on the label is even in the bottle, which it often is not.

Don't chase the one ideal diet, because it doesn't exist. We evolved to thrive on a variety of foods and a variety of diets. That's a big part of why humans have spread all over the planet. You can ignore fad diets, and a quick way to spot a fad diet is that it has a name. The one sort-of exception is the so-called Mediterranean Diet. It doesn't have any precise definition, but most descriptions of it boil down to a variety of food, mostly plants. Do you need to go Atkins, Whole30, paleo, or keto? No.

So let's go shopping. You can safely ignore fashionable advice to "shop around the edges" of the store, because the middle has all kinds of wonderful foods, such as canned beans and veggies, that are perfectly appropriate to form a large part of a varied, healthy diet. But do spend some time in the produce section. This is your big chance to get some yummy variety in the form of fruits and veggies. Try bringing home something new every time you go, then look up ways to prepare and serve it.

Do keep in mind that most Americans get the bulk of their calories from just a few species, mostly wheat, potatoes, and corn. Learn to read the ingredients on foods to see what they're mostly made of. The first items listed form the bulk of it, and you can pretty much ignore everything at the end of the list. Speaking of which, don't fall for the fear-based tactic of frightening you away from "ingredients you can't pronounce". How well you recognize a chemical name has nothing to do with its safety or nutrition. As you add things to your cart, just think variety.

Oh, look! There's a big organic foods section. It's kind of expensive, but must be worth it because it's healthier and doesn't have any pesticides. Right?

Wrong. In the U.S. the organic regulations were literally written by lobbyists for the organic food industry. These are regulated agricultural practices which have nothing to do with nutrition or safety. There is no nutritional advantage to organic food over conventional, and not only do they use pesticides, but very often pesticides that are more toxic than conventional, so-called synthetic ones. "Organic" is, in the context of food, merely a marketing term used in one of the most successful fear-based campaigns ever. The industry has spent millions trying to make you afraid of anything that isn't organic. It's fundamentally dishonest. Note that this doesn't mean that there's anything wrong with organic food. If you find some you like and don't mind the price, it certainly won't hurt you. But it does take up a lot more arable land, because organic yields are lower than conventional agriculture.

Most of the anti-GMO propaganda you hear is funded by Big Organic. Much of the rest, believe it or not, is Russian disinformation. GMO foods have been so effectively demonized that this is one of the biggest opinion gaps between scientists and the public at large. Scientists overwhelmingly understand that GMOs are completely safe, while a disappointing percentage of the public fears otherwise. The executive summary on GMOs is that they have been well-tested for decades and found to be safe. Some crops, such as Hawaiian papaya, were rescued from extinction by genetic modification, and others, such as golden rice, can prevent blindness and other diseases in parts of the world where vitamin A deficiency is common.

But what about pesticides in your food? This is a common fear-mongering topic because who isn't afraid of "toxins" in their food? Here are two things to remember: First, if you simply wash your produce, the amount of residual pesticides from agriculture is so vanishingly small that it can't hurt you. Farmers can't afford to waste money, so they don't soak their crops in pesticides when a small amount does the trick. Note also that most are of extremely low toxicity to humans anyway because we aren't weeds and we aren't insects. Second, the vast majority of the pesticides you eat are produced naturally by the plant you are eating. Cabbage produces around 46 toxins on its own. Again, you don't have to worry about it because you aren't a bug.

One more tip: Never go on a weight loss diet. They don't work. Why they don't is more than enough for a separate episode, but check the references in the show notes for an excellent book on the subject. Before attempting to lose weight see your qualified medical practitioner. The fact is that there is no one ideal weight for you, but a range of healthy weights. Generally you want to be toward the lean end of that range. And the only way to get there and stay there is to change the way you eat for the rest of your life. A temporary diet will never have permanent benefits. Note that cutting down on some sugar and getting more vegetables, which are not calorie dense, is about the only change most people need to make. Don't buy any weight loss products or services. If one of the new drugs that can help, such as semaglutide, is right for you your doctor will know.

So take the long view. Don't pick specific foods because of supposed "health benefits". Ignore anybody telling you that a food or ingredient is "bad". Pack your shopping cart with an eye toward getting a variety of species and a variety of foods. Maybe don't keep treat foods in the house, but enjoy a nice dessert now and then when you go out. Don't let anybody ever make you feel bad or guilty about what you eat. Food should be a source not just of nourishment, but of joy and community. And when you learn to cook, it can also be art.

So enjoy a variety of foods, mostly plants, with plenty of fruits and veggies, not too much or too little. In sum, relax and enjoy your food.

By Craig Good