How does weight loss help control Type 2 diabetes?

DEAR DOCTOR K:

I was recently diagnosed with Type 2 diabetes. My doctor said the best thing I can do right now is to lose weight. Why?

DEAR READER:

Type 2 diabetes usually starts after a person becomes an adult. It is by far the most common type of diabetes. It has been clear for many years that people who are overweight are at much greater risk for developing Type 2 diabetes. In the past 20 years, research discoveries have begun to explain why.

We used to think of fat as an inert layer of insulation. In recent years, we’ve discovered that the special cells inside fat (“fat cells”) are not inert at all: They are little hormone-producing factories. The hormones they make travel through the blood to the brain and other organs. They influence a person’s appetite and metabolism. They also influence the amount of sugar in the blood. Diabetes, of course, is marked by high levels of glucose (sugar) in the blood and urine.

Your doctor’s recommendation is right in line with guidelines from the American Diabetes Association (ADA). They urge all people newly diagnosed with diabetes to lose weight as the first step to controlling their blood sugar. The best way to lose weight? By eating more healthfully and exercising more.

A blood test called HbA1c estimates average blood sugar levels over the past two or three months. People with diabetes should aim for an HbA1c level of less than 7 percent. Losing weight and exercising more can decrease your HbA1c level by one or two percentage points. That may not sound like much, but a two-point reduction in HbA1c can put your blood sugar in the normal range, dramatically reducing your chances of developing a diabetes-related health problem.

How much weight do you need to lose to see improvements? If you are overweight, losing just 5 to 10 percent of your starting weight can help you manage your diabetes. Not all people with Type 2 diabetes are overweight. But even if your weight is in the healthy range, losing three to five pounds can help control your blood sugar.

What’s most important is that the diet delivers fewer calories than you burn each day. That imbalance translates into weight loss. For lasting weight loss, choose an appealing diet so you can stick with it. (Of course, for long-term health, it’s also important to choose a diet based on healthy foods.)

So how can you cut calories? First, eat smaller portions. Also, substitute lower-calorie alternatives for high-calorie foods. For example, have grilled fish and steamed vegetables for dinner instead of a plate of pasta.

It also helps to stick with a regular eating schedule. Plan meals and snacks that are no more than four hours apart to help keep you from becoming too hungry and overeating.

I have known many patients who were able to control their Type 2 diabetes with just diet and exercise. They did not need medicine. Diet and exercise really are that effective.