Good carbs include unprocessed grains like whole wheat, spelt, and buckwheat.

Good Carbs vs. Bad Carbs and Why It Matters

As a health-conscious runner-in-training, you’ve probably been hearing a lot about how you need to prioritize “good carbs” over “bad carbs.” But how do you know which is which? “Think of so-called good carbs as those that haven’t been changed much from the way they occur in nature,” says Heather D’Eliso Gordon, sports dietician and nutrition health coach in the Health Education Department at Kaiser Permanente San Francisco. “Foods that are closer to the original source are more nutrient dense, contain more fiber, and don’t spike your blood sugar.”

Carbohydrates come in two forms, simple and complex. Simple carbohydrates are sugars, and complex carbohydrates are formed by linking together several sugar chains. Many people equate simple carbohydrates with “bad” carbs and complex carbohydrates with the “good” carbs, and that’s generally true.

But unfortunately it’s more complicated than that. Grains such as wheat and rice, which in their natural state are considered complex carbohydrates, become “bad” carbs once they’re refined and processed. And  fruit, which technically falls into the simple carb category because of its fructose content, is very good for you. Here’s a quick checklist of good carbs vs. bad carbs.

“Bad” carbs

  • Sugar
  • White flour
  • White rice
  • White flour pasta
  • Soda pop
  • Cakes and cookies
  • Chips

“Good” carbs

  • Fruits
  • vegetables
  • Beans
  • Whole grains (including whole wheat flour and brown rice)
  • Whole grain pasta and other whole grain products

The reason it’s so important for runners to choose good carbs is that they’re slower to digest, releasing energy more gradually.  “Providing your body calories from whole, un-processed carbohydrate sources along with moderate amounts of protein and fat gives you a steady supply of energy rather than a quick burst of energy that’s gone right away,” says Gordon.

Bad carbs, on the other hand, do just the opposite. “Foods made with white flour and white sugar like scones, bagels, or croissants  will leave you feeling tired and hungry just a couple of hours later,” says Gordon. “If you’re going to eat a bagel, make it a whole wheat bagel.”

Gordon is a fan of many of the newer types of whole grains you might have noticed appearing on grocery store shelves, such as quinoa, millet, kasha, and even good old-fashioned grits. She particularly favors specialized grains such as black rice, red Bhutanese rice, and faro. “Since you eat whole grains every day, why eat the same ones over and over?” she asks. “It’s always best to eat the widest possible variety of foods.”

Beans and legumes, which many people don’t realize are carbohydrates, are another of Gordon’s favorite type of complex carb. “Beans and legumes are super rich in minerals and vitamins,” she says. In addition some, such as lentils, are known for their “satiety factor,”  trigger feelings of fullness and reducing your appetite.

Heather D'Eliso Gordon is a Nutrition Health Coach and Sports Dietitian in the Health Education department of Kaiser Permanente San Francisco. A certified specialist in sports dietetics, Heather works with both recreational and competitive athletes to create optimal nutrition plans that support their fitness goals. She also provides nutrition coaching to Kaiser Permanente patients pursuing weight loss goals or coping with diabetes, high cholesterol, celiac disease, and other conditions.