Diabetes Health Center

Diabetes and Weight Loss

Watch the Carbs on a Diabetes Weight Loss Diet

For people with diabetes, a refresher course on carbs may also be in order, Gerbstadt says. With diabetes and weight loss, dietary changes must be made carefully.

That's because carbs have the biggest effect on blood sugar, since they are broken down into sugar early in digestion. Eating complex carbs (whole-grain bread and vegetables, for example) is good because they are absorbed more slowly into the bloodstream, cutting the risk of blood sugar spikes, Gerbstadt explains.

"Worst-case scenario is sliced white bread," she says. "Whole-wheat bread is an improvement. Adding a little peanut butter is even better."

Exercise, Diabetes, and Weight Loss

For those with diabetes trying to lose weight, one of the benefits of exercise is that it helps keep your blood sugar in balance, so you won't have to cut as many calories.

"Walk an extra 20 minutes a day, and you can eat a little bit more," Gerbstadt explains, and instead of cutting 500 calories, "you can cut back just 200 or 300 calories, and still get excellent results in weight loss. You'll also control your blood sugar. And the weight will be more likely to stay off if you lose it slowly, safely."

Keep in mind: Each type of exercise affects blood sugar differently.

Aerobic exercise -- running or a treadmill workout -- can lower your blood sugar immediately.

Weight lifting or prolonged strenuous exercise may affect your blood sugar level many hours later. This can be a problem, especially when you're driving a car. It is one of the many reasons that you should check your blood sugar before driving. It's also a good idea to carry snacks such as fruit, crackers, juice, and soda in the car.

"With physical activity, you burn blood sugar as well as sugar stored in muscle and in the liver," explains Luigi Meneghini, MD, director of the Kosnow Diabetes Treatment Center at the University of Miami School of Medicine. "People using insulin or medications to simulate release of insulin should closely monitor blood sugar levels when they begin exercising more. Over time, as you exercise regularly, you can reduce doses of medications and insulin."

Special Challenges on Diabetes Weight Loss Diets

"For anyone, losing weight is challenging enough," Meneghini tells WebMD. "For people who inject insulin, it's even more difficult because they have to eat when they have low blood sugar. When you have to reduce calorie intake, prevent overmedication, and eat to correct your low blood sugar, it's very challenging."

Indeed, both low and high blood sugar levels are the two big concerns with diabetes and weight loss.

• Low Blood Sugar (hypoglycemia) occurs when the amount of insulin in the body is higher than your body needs. In its earliest stages, low blood sugar causes confusion, dizziness, and shakiness. In its later stages, it can be very dangerous -- possibly causing fainting, even coma.

In patients who take insulin or certain diabetes drugs, low blood sugar is common when people lose weight because cutting calories and weight loss itself affect blood sugar levels. If you don't reduce your insulin dosage or pills to match new blood sugar levels, you'll be risking high blood sugar.

• High Blood Sugar (hyperglycemia) can develop when your body's insulin level is too low to control blood sugar. This happens when people on insulin or sugar-lowering medications don't take the correct dose or follow their diet.