Things like high-fructose corn syrup and trans fats are two highly publicized examples. When we think of highly processed foods, we think of McDonald’s, KFC, or food you might buy at the gas station. But do most people think about yogurt, pasta, or even oatmeal as being processed?

But as real-food visionary and endocrinologist Robert Lustig, M.D., says, “It’s not what’s in the food—it’s what’s been done to the food that counts.” In other words, people get a little too hung up on whether it’s sugar or fat or salt that we should be avoiding in our food and forget to look at the other dimensions of what’s on our plate.

For instance, depending on which brand you happen to snag at the store, your yogurt might not be just cow’s milk fermented with some good-for-your-gut microbes—it could also include fat replacements and “natural flavors” that are just chemicals designed to smell like the real fruit they have neglected to actually include in that “blueberry” yogurt. Artificial sweeteners are everywhere, and some like aspartame are associated with a greater risk of cancer4. So we have starches, gums, thickeners, and sugars going in, and fiber, fat, and micronutrients coming out, and often we have no idea what the wizard is doing behind the curtain to make it all happen.