Of all the changes Tarzan made to recover his metabolic health, switching to a real food diet was the most important.

• Real food is meat, eggs, dairy, fish, seafood, vegetables, fruit, grains, nuts, seeds, spices, oils and fats in as close to their natural form as possible. If they are processed in a way that reduces their nutritional value, they are not real foods.
• Real foods generally do not have ingredient labels, because they have only one ingredient. If they do have ingredients, they are small in number and are themselves all real foods.

Here are few examples of what I mean:

Fruit – A piece of fruit is real food. Fruit juice is not (it contains way too much sugar). Fruit smoothies are worse. Fruit juice concentrate (used as a sweetener) is basically just sugar.

Vegetables – A vegetable is a real food, but processing can render them metabolically problematic. For example, a tomato is obviously a real food. Canned tomatoes can be, as can tomato sauce and tomato paste. When we get to tomato-based sauces, things can go downhill fast. Many pasta sauces contain sugar and artificial oils. When buying pasta sauce look for those that are made up of real foods (e.g., tomatoes, olive oil, and spices).

Dairy – Whole milk, butter, ghee, cheese, full-fat yoghurt, kefir (fermented milk) are real foods. Margarine is not. Low-fat yoghurt (usually containing a lot of sugar) is not.

Meat – A piece of meat is a real food. Problems come in with packaged meats, which can vary greatly in their processing. Often sugar and chemical additives are found in packaged meats.

Nuts and Seeds – Nuts and seeds are real foods. A nut butter (or seed butter) can be pretty much a real food provided it is just the nuts or seeds, mashed up and put in a jar; but often sugar and artificial oils are added to the mix.

Grains – We are advised to include a lot of whole grains in our diet, but we are not given much guidance on how to know what is the best choice in the bread, cereal and pasta aisles. For a product to be labeled “Whole grain” it must contain the entire kernel of the grain; but that can mean a product that contains the whole, intact grain kernel, or it could mean a product in which the grain kernel has been ground into a fine flour, causing the loss of much of the benefit of the whole kernel. It will be digested quickly and will lead to an increase in blood glucose and insulin.

Also, a product can be labeled “whole grain” if the grain in a product has at least 51% whole grain content by weight. The rest can be regular flour. (In products labeled “100% whole grain,” all the grain in the package must include the entire kernel.)

Most of the whole grain products at the supermarket will be of the finely-ground flour variety. That is true of bread, cereal and pasta. It is marginally better than regular flour, but it is not a healthy option.

Bread is so ingrained (see what I did there) in our culture it’s hard to believe that it could be part of what’s making us sick. But it is. The bread we find today at the local Piggly-Wiggly is far different than that eaten by our ancestors. In biblical times the grain was ground between a couple of rocks and the resulting bread would have been very heavy and coarse. Such bread would have taken longer to digest, and the glucose would have entered the bloodstream more slowly, making it less metabolically damaging. Starting with the industrial revolution, industry has produced ever-finer and easier to digest flour. Modern breads are lighter than ever, and much more intensely processed. Those changes have continued into the 21st century. Bread, cereal and pasta made from this flour is a threat to our metabolic health.

If we want to find “real food” bread, we could perhaps procure it from an artisan baker who uses ancient techniques to bake bread. Or we could turn to something like “Ezekiel Bread,” which is made from grains that are sprouted and then mashed into dough before baking. Not only do these types of bread produce a much lower glucose spike, we are also much less likely to overeat them. (I could eat a dozen dinner rolls without breaking a sweat; no way would I eat a dozen slices of Ezekiel bread.)

As for other grains: brown rice and steel-cut oats are unprocessed and don’t cause as much of a glucose rise as would minute rice and instant oatmeal, but they still cause a significant rise and could be a problem for many of us (same with corn). As with any food, different people respond differently. How much we must limit these grains will vary based on how we as individuals respond to them. Grains are not essential nutrients; it is not necessary to include them in our diets.

One other note about real food: There is much emphasis these days on “plant-based” diets in the media. Some people appear to thrive on properly formulated plant-based diets, and realize better health outcomes than when eating a typical American diet; but it is also true that many people thrive on real-food diets that include quite a lot of meat and other animal products.

A review published in the Annals of Internal Medicine concluded that the evidence on the effects of eating red meat does not support the recommendation to limit red meat consumption. Other researchers dispute that conclusion. There are no randomized controlled studies comparing people eating red meat with those who don’t (and holding everything else constant) that show that red meat is harmful. There is no reason to assume that plant foods are better for us than animal products.

And one point about sugar:

Sugar is one area where natural vs. processed doesn’t make as much difference as one might hope. High-fructose corn syrup is without doubt a highly processed food, and the fructose and glucose enter the bloodstream a little more quickly than table sugar; but once there they have exactly the same effect. Molecules of fructose and glucose are molecules of fructose and glucose, whether they come from pure cane sugar, high-fructose corn syrup, honey, a date, fruit-juice concentrate or any of the other sixty-some sources of sugar we see on food labels. Some sugar sources may carry with them additional nutrients along with the sugar, but if we eat more fructose and glucose than our bodies were designed to handle our health will suffer.