Diabetes and Weight Loss: The Right Path

If you've got diabetes, weight loss can get you off insulin and other medications. But diet safely, with the help of experts.

Medically Reviewed by Brunilda Nazario, MD on October 23, 2009
From the WebMD Archives

Diabetes and weight loss: They're the yin and yang of optimal health. There's no question about it: If you're overweight and have type 2 diabetes, dropping pounds lowers your blood sugar, improves your health, and helps you feel better.

But before you start a weight loss plan, it's important to work closely with your doctor or diabetes educator. That's because while you're dieting, your blood sugar, insulin, and medications need special attention.

Make no mistake: You're on the right path.

"No matter how heavy you are, you will significantly lower your blood sugar if you lose some weight," says Cathy Nonas, MS, RD, a spokeswoman for the American Dietetic Association and a professor at Mount Sinai School of Medicine in New York.

A 2001 National Institutes of Health study found that a combination of diet and exercise cuts the risk of developing diabetes by 58%. The study involved people who were overweight (with an average body mass index of 34) and who had high -- but not yet diabetic -- blood sugar levels.

"We know it's true -- that if someone with diabetes loses 5% to 10% of their weight, they will significantly reduce their blood sugar," Nonas tells WebMD.

"We see it all the time: people can get off their insulin and their medication," she says. "It's wonderful. It shows you how interwoven obesity and diabetes are."

Even losing 10 or 15 pounds has health benefits, says the American Diabetes Association. It can:

Plus, you'll probably have more energy, get around easier, and breathe easier.

Diabetes, Weight Loss, and Changes in Blood Sugar

Cutting back on just one meal can affect the delicate balance of blood sugar, insulin, and medication in your body. So it's important to work with an expert when you diet.

Check with your doctor before starting a weight loss plan, then consult with a diabetes educator or nutritionist, advises Larry C. Deeb, MD, a diabetes specialist in Tallahassee, Fla., and past president of the American Diabetes Association.

"Don't try to lose weight on your own," says Deeb. "With a doctor and a good nutritionist, it's very safe to do. This is very important if you're taking insulin or medications.

The Right Balance for Diabetes and Weight Loss

Christine Gerbstadt, MD, a spokeswoman for the American Dietetic Association, warns: "You don't want to run the risk of high or low blood sugar while you're dieting. You want tight glucose control while you lose weight."

Gerbstadt suggests cutting 500 calories a day, "which is safe for someone with diabetes," she says. "Cut calories across the board -- from protein, carbohydrates, and fat -- that's the best way." She recommends that people with diabetes maintain a healthy ratio of carbs, fat, and protein. The ideal:

  • 50% to 55% carbs
  • 30% fat
  • 10% to 15% protein

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."

Simply cutting lots of carbs -- a common dieting strategy -- can be dangerous for a diabetic diet, Gerbstadt says. When your body doesn't have carbs to burn for fuel, your metabolism changes into what's known as ketosis -- and fat is burned instead. You'll feel less hungry, and eat less than you usually do -- but long-term ketosis can cause health problems.

"Ketosis decreases oxygen delivery to the tissues, which puts stress on eyes, kidneys, heart, liver," Gerbstadt says. "That's why the low-carb, high-protein Atkins diet is not really safe for people with diabetes. Diabetics need to try to stick with a more balanced diet so your body can handle nutrients without going into ketosis."

Exercise, Diabetes and Weight Loss

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. So 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. 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 to help your diabetic diet.

"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 stimulate 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 for 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, 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, it causes confusion, dizziness, and shakiness. In its later stages, it can be very dangerous -- possibly causing fainting, even coma.

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 diets.

Diabetes and Weight Loss: Getting Started

Losing weight is never easy. That's where a diabetes educator or a nutritionist can help, advises Deeb, president-elect of the American Diabetes Association. A diabetes educator or nutritionist can develop a program that fits you and your lifestyle -- a program with realistic goals, he says.

"You will need a meal plan, one that you can follow every day. You'll need to know how to alter your insulin and medication based on what you're eating and whether you're exercising more," Deeb tells WebMD. "That's the safest way to lose weight."

A consultation with a diabetes educator or dietitian/nutritionist can cost from $60-$70. Typically, insurance covers the first two visits, but may not additional ones, says Meneghini.

Reasonably priced support groups and classes are available, frequently through hospitals, to help with diabetes and weight loss. Ask your doctor or physician assistant for recommendations.

There are also web sites with in-depth information on diabetes and weight loss, including:

  • American Diabetes Association at
  • National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

"Information is power, and the better informed you are, the better decisions you can make," says Meneghini.

WebMD Feature


SOURCES: Cathy Nonas, MS, RD, spokeswoman, American Dietetic Association. Christine Gerbstadt, MD, MPH, RD, LDN, spokeswoman, American Dietetic Association. Luigi Meneghini, MD, director, Kosnow Diabetes Treatment Center, University of Miami School of Medicine. National Institute of Diabetes and Digestive and Kidney Diseases: "Taking Care of Your Diabetes at Special Times." Larry C. Deeb, MD, president-elect, American Diabetes Association. WebMD Medical News: "How to Avoid Diabetes - Landmark Results Unveiled." American Diabetes Association: "Healthy Weight Loss." WebMD Medical Reference with the Cleveland Clinic: "Diabetes." WebMD Medical Reference with the Cleveland Clinic: "Weight Loss."

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