How do food, sleep and exercise affect blood sugar? Here’s what to know. More than one in three adults in the United States has prediabetes, higher-than-normal blood sugar levels that can lead to diabetes. And more than one in 10 has diabetes, characterised by still higher blood sugar levels that can eventually lead to eye problems, heart disease, a stroke, nerve damage and other serious health issues.

It’s possible to avoid these complications by keeping your blood sugar in check. What you eat, when you eat, your exercise habits and even how stressed you are all can affect how high (or low) your sugar level goes. “You don’t want to wait until you have prediabetes or diabetes to start thinking about it,” said Dr Elizabeth Halprin, chief of adult diabetes at the Joslin Diabetes Center in Boston.

“You want to think about it to prevent it.” What is blood glucose?.