A large study of whether diet and weight loss can prevent heart attacks and strokes in people with Type 2 diabetes who are overweight or obese has ended early because of the ineffectiveness of the program. 11 years after the study began; researchers concluded that there was no reason to continue.
Rena Wing, the study’s chairwoman and a professor of psychiatry and human behavior at Brown University’s medical school, said, “I was surprised.” She had assumed diet and exercise would help because short-term studies found that they were effective in lowering cholesterol levels, blood sugar levels, and blood pressure. An earlier study found that an intense diet and exercise program also helped prevent diabetes in overweight or obese people with elevated blood sugar levels.
It seemed logical that diet and exercise would help reduce risk of heart disease. Dr. Wing said, “You do a study because you don’t know the answer.” Around 25 million Americans are living with Type 2 diabetes and many of them are overweight or obese. Type 2 diabetes has been found to increase heart disease risk by 2 to 2 ½ times. Medical experts say that there are still many benefits to diet and exercise that cannot be overlooked.
The study randomly assigned 5,145 participants with Type 2 diabetes to either a rigorous diet and exercise program or to sessions to receive general health information. The diet had restrictions of 1,200 to 1,500 calories a day for those weighing under 250 pounds and 1,500 to 1,800 calories a day for those who weighed more. The exercise program required at least 175 minutes a week of moderate exercise.