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We are not here to vilify carbs — they’re fuel for our bodies — but not all carbs are created equal. We look at the science behind why eating too much starch isn’t good for you and share four tips to help you integrate grains into your diet.

1. Not all calories act the same in the body.

Just because two foods have the same number of calories doesn’t mean they’re equal health-wise. “We’ve known for decades, if not a century, that different foods affect the body differently, apart from their calorie content,” says David Ludwig, a professor of nutrition at the Harvard T.H. Chan School of Public Health and the founder of a weight loss center at Boston Children’s Hospital.

If you take white bread and whole-grain wheat kernels that have about the same number of calories, the whole grain has so much more going for it. Eating minimally processed grain like wheat berries, whole oats, barley and rye is better for you than superprocessed white bread. Ludwig says that’s because they take longer to digest. “Blood sugar rises relatively more gently. You produce less insulin, calorie for calorie.”

When you eat white bread, on the other hand, all the good-for-you stuff is processed out of the bread, leaving a bunch of starch, which can raise blood sugar and insulin, potentially stimulating hunger and maybe even slowing down your metabolism.

2. Refined carbs quickly turn to sugar in your body.

You’ve heard to cut back on sugar. But consider this: Ultra-refined grains (whether it’s crackers, baguettes or white bread) are just one step away from turning into sugar in our bodies. And as we just outlined, ultra-processed, starchy foods can raise blood sugar and insulin. Ludwig says this can direct calories more into storage and fat cells, meaning “there are fewer calories available for the rest of the body, for the organs, the muscles and the brain,” he says. “That’s why we get hungry.”

Don’t worry — you can still eat bread. There are just much better options than white bread. For example, traditional pumpernickel, sourdough or other whole grains.

What does the phrase “whole grains” really mean? Whole grains have three parts. In the center, there is a germ. Think of it as a tiny packet of nutrients — it has protein and a few essential fatty acids. Then there is the bran, which is fiber — that’s good for digestive health. The third part of the grain is called endosperm, which is usually what’s left in processed carbs. It’s really just starch. However, when you eat whole grains, you get all three parts.

The Truth About Carbs And Calories

Photo: C.J. Burton/Corbis/Getty Images