Benefits of Weight Loss in Diabetes Questioned

A new study may be questioning the advice that obese people with type 2 diabetes should lose weight to improve their health.

A recent study showed that obese people with diabetes who lost a modest amount of weight didn’t lower their risk of having a heart attack or stroke, but the weight loss did help improve many other health factors.

Rena Wing, a professor of psychiatry and human behavior at Brown University and chairman of the Look AHEAD (Action for Health in Diabetes) study stated that, "While we did not show a benefit of modest weight loss for cardiovascular events, we did show the benefits of weight loss for improving depression, quality of life, sleep apnea, incontinence, fitness, physical function and blood sugar control."

For the study, researchers at 16 centers around the country worked with 5,145 obese people with type 2 diabetes. Their average starting weight was about 200 pounds. The study was designed to see whether weight loss reduced the risk of heart attacks and strokes.

Half of the participants were assigned to an intensive diet and exercise program. They attended individual and group meetings where they were taught strategies for weight loss by cutting calories and increasing physical activity. They used some meal replacements during the weight-loss and maintenance phases of the program.

The other half received a general program of diabetes education several times a year. All participants continued to follow the medical advice of their physician.

Findings: Those in the diet group lost about 8% of their starting weight (about 16 pounds) in the first year and maintained nearly 5% (about 10 pounds) of that loss. Participants in the diabetes education group lost about 1% (2 pounds) of their starting weight and kept it off. Everyone was tracked for up to 11 years.

After four years, the findings showed that those in the diet-and-exercise group improved their hemoglobin A1C readings, fitness, systolic blood pressure and HDL cholesterol more than those in the diabetes education group. The diet-and-exercise group also required less medication to control the diabetes.

Participants in the diabetes education group, however, had better LDL cholesterol at year four, possibly because more of them were taking cholesterol-lowering drugs, Wing says.

There was no difference between the two groups in the incidence of heart attacks and strokes, but the incidence was low in both groups, she says. "The fact that they had lower rates of cardiovascular disease than we expected probably reflects improvements in medical management of diabetes."

Wing says researchers will continue to monitor the study participants to see whether their weight loss lowered their heart attacks later in their lives and to assess other possible long-term benefits of weight loss.

"The study provides important information, but we don’t know from this study whether larger weight loss would have better impact, and we don’t know if these weight losses would have decreased the risk of heart attacks and strokes in people without diabetes," she says.

Thomas Wadden, director of the Center for Weight and Eating Disorders at the University of Pennsylvania’s Perelman School of Medicine, adds: "Regardless of its effects on heart disease, modest weight loss and increased physical activity improve multiple aspects of health and well-being in overweight individuals with and without diabetes. Let’s not throw out the baby with the bathwater."

Look AHEAD (Action for Health in Diabetes) study, CDC