“What we know in diabetes prevention, and in prediabetes, is that a very modest amount of weight loss has this huge reduction in risk,” Marrero says. “You lose 7% of your body weight, you cut your risk [of developing diabetes] by 60%. And, in fact, if you’re over 65, it’s over 70%. But how do you not just lose weight, but keep it off? Through a combination of exercise and watching what you eat. The Exercise Factor. If you’re overweight and have diabetes, or are at risk of getting it, you have to exercise. There’s no way around it.