Regularly overindulging in simple, high-GI carbs—the kind that produce the beloved sugar rush—can be dangerous. "There's a lot of evidence that blood glucose spikes are bad for your heart and can raise your risk for type 2 diabetes," says Brand-Miller. "We're beginning to think that type 2 diabetes develops from a process of exhaustion, in which the cells that produce insulin just can't keep up with the high demand, day after day, year after year." Those glucose spikes, says Brand-Miller, are also thought to indirectly cause irritation of the cells lining the blood vessels, which can lead to inflammation and plaque buildup—risk factors for heart disease.
Our December issue features Oprah's Favorite Things—as well as your chance to win them all! You'll also find our easy holiday declutter plan, Dr. Oz's guide to sleeping better (starting tonight) and the ultimate holiday menu.