I’ve been thinking about an idea that I am calling a “hierarchy of carbohydrates.” This concept divides the enormous category of carbohydrates into discrete groups, each of which affects insulin release differently.

The most basic level in the hierarchy of carbohydrates is green vegetables. Yes, green vegetables are carbohydrates, though people tend to use the term to indicate only grain. But when it comes to greens, the total amount of carbohydrate in these is so low–compared with the high levels of nutrients they contain–that you should feel encouraged to pile your plate as high as you like with all kinds of green, leafy vegetables. You needn’t be at all concerned about the volume of green leaves you eat. They’re free.

The next level in the carbohydrate hierarchy is beans. Black beans, fava beans, pinto beans, kidney beans, turtle beans, navy beans, and America’s favorite bean: peanuts. Very few diets advocate avoiding beans. They are the only food in the universe that is high in both fiber and protein at the same time. Double whammy.

The next level in the carbohydrate hierarchy is fruit. Some fruits, like mangoes and pineapple, contain larger amounts of sugar than others, like berries, cherries, grapefruit, apples, peaches, plums. So if you’re looking for a way to conserve insulin, and you’ve already reduced the amount of stripped and whole grain you eat, reducing your intake of fruit may work in your favor.

The next level up in the hierarchy of carbohydrates is root vegetables, such as potatoes, parsnips, sweet potatoes, and beets. These examples, along with squash and pumpkins, ripen toward the end of the growing season. Think about the fact that food was traditionally more scarce in the wintertime. Hence, a cellar filled with root vegetables would be an insurance policy against starvation. These foods are designed by nature to provide the body with a little bit of winter insulation (i.e., body fat storage) at precisely the time we need it.

So should you avoid root vegetables? Maybe yes, maybe no. They are, generally speaking, rich in phytonutrients. If you are active and you are satisfied that your weight is in a normal range, assume that you are making good choices as far as root veggies go. If, on the other hand, you are struggling to keep your insulation in a reasonable range, and you’ve already reduced the amount of stripped and whole grain in your diet, you may discover that decreasing root vegetables, especially fried potatoes, is helpful.

Grain is the next level in the hierarchy of carbs, and this is where it gets more personal. Large numbers of people report that the more grain they eat, even whole grain, the more difficult it becomes to maintain a healthy weight, modulate their appetite, and stabilize energy levels. Though not all people feel this way, some do. Trust your body, and respect what it is telling you. You might want to try limiting grain-based products for a couple of weeks. Wheat, corn, oats, rice, barley, buckwheat, rice, or products made from them. See what happens. See how you feel. See how your pants fit.

A discussion about dietary carbohydrate is not complete without a conversation about white flour and sugar. If you look above, or look outdoors, you will notice that carbohydrate virtually never exists without an intact fiber matrix. So how did it get that way? Humans figured out how to remove it.

White flour and sugar are examples of what happens to carbohydrate after its fiber is stripped out. Sugar is what’s left when you remove the fiber from beets, dates, or sugar cane. Remove the fiber and germ from wheat, and what’s left is termed white flour, or refined flour. To “refine” is to remove coarse impurities. Calling it refined wheat is spin. Historically speaking, these products are relatively recent inventions. They have been available for human consumption for only a few hundred years. Before that, humans did not, for the most part, eat stripped carbohydrate. Except perhaps for honey and maple syrup, it simply did not exist.

Eating stripped flour and sugar is like serving carbohydrates on a silver platter. They have already been partially broken down, or pre-digested, and all that’s left is for our own guts to finish the process. When food is broken down before it even enters your mouth, there’s less work of digestion. This is why stripped carbs are absorbed so quickly and blood sugars rise accordingly. The more rapidly your blood sugars rise, the more insulin you release to catch all the incoming sugar. Wasting insulin is exactly the opposite of your intended goal. 

An important secondary benefit of reducing the amount of white flour and sugar in your diet is that you significantly decrease the amount of manufactured calories, or ultraprocessed items, in your diet. You stand to reap substantial benefits by doing this. Anyone attempting to conserve insulin is advised to limit, as much as possible, their consumption of white flour and sugar. I make an exception for birthday cake. But the typical American diet, with 6-12 servings of stripped carbohydrate daily, is a prescription for diabetes.

To summarize: The most basic level is green vegetables, and these are especially nutritious. It is the rare individual who wouldn’t benefit from eating more. Next come the beans (legumes), root vegetables, fruits, and whole grains. Also valuable sources of nutrition. The last level is stripped flour and sugar, which is not nourishing and would best be limited to special occasions. With the exception of this final level, the rest of these are examples of nourishing food. Somewhere within these levels is the balance that will provide you with the materials you need to thrive. Use the hierarchy of carbohydrates to figure out your own best strategy for healthy living.