According to data from the Centers for Disease Control and Prevention (CDC)’s Diabetes Prevention Program, losing 5 to 10 percent of your weight in six months can help improve blood sugar, blood pressure, and blood cholesterol. In the study, among overweight and obese people with prediabetes who achieved 5 percent or more weight loss initially, the percentage who kept the weight off over time was greater among those taking metformin — a medication that helps control high blood sugar and can aid weight loss — than those who made intensive lifestyle changes. “We were surprised by the resilience of the metformin group in not regaining weight they lost in the first year,” says study author Kishore Gadde, MD, a professor in heart disease prevention at the Pennington Biomedical Research Center in Baton Rouge, Louisiana. “While there was individual variability, those assigned to receive metformin collectively performed very well in the long term, especially in the last 10 years of the 15-year follow-up.” RELATED: Metformin Linked With Lower Risk of Death From COVID-19 in People With Type 2 Diabetes Although the weight loss mechanism behind metformin is unclear, the Mayo Clinic notes that the drug seems to reduce hunger, and two of the drug’s side effects — diarrhea and upset stomach — could also reduce how much someone eats. The CDC estimates that 100 million American adults have prediabetes or diabetes. The agency estimates that 30.3 million Americans have diabetes, with 90 to 95 percent of those cases type 2. Of the total with diabetes, 7.2 million are undiagnosed. Meanwhile, 4 in 10 American adults have obesity, according to the CDC, and extra weight not only raises the risk of type 2 diabetes but also heart disease and some types of cancer. RELATED: Does Metformin Cause Weight Loss? What to Know Before You Take It
Could Metformin Be a Possible Lasting Solution for Weight Control?
Dr. Gadde and his fellow investigators tracked 3,234 people who had obesity or were overweight, and had elevated blood sugar levels. Researchers randomly selected them to receive either metformin, a placebo, or an intensive diet and exercise program. Those in the lifestyle intervention group completed 16 sessions where they learned how to eat healthful foods, reduce their calorie and fat intake, and develop an exercise regimen incorporating 150 minutes of moderate-intensity physical activity, such as walking, per week. During the first year, the lifestyle intervention patients lost the most weight. Nearly 63 percent in this group lost at least 5 percent of their weight in the first year compared with 28.5 percent in the metformin group and 13.4 percent in the placebo group. Yet investigators observed that the highest proportion of those who kept pounds off after 6 to 15 years was in the metformin group. The percentage who maintained more than 5 percent weight loss was 56 percent in the metformin group versus 43 percent in the lifestyle group and 42 percent in the placebo arm. RELATED: Losing This Much Weight May Put Type 2 Diabetes in Remission, Study Suggests
Why Keeping Lost Weight off for Good Tends to Be So Challenging
Kevin M. Pantalone, DO, an endocrinologist at Cleveland Clinic in Twinsburg, Ohio, and the director of clinical research of Cleveland Clinic’s Endocrinology and Metabolism Institute, suspects that the metformin participants had better long-term outcomes than the lifestyle group because taking daily pills may be easier to continue over time compared with dramatic dietary and exercise changes. “Keeping patients engaged in lifestyle modifications, or other weight loss efforts in general, is challenging in the long term, as enthusiasm wanes, or because the weight loss invariably hits a plateau, and patients can become frustrated and disengage as a result,” says Dr. Pantalone, who was not involved in the study. He believes that the simultaneous use of medication and lifestyle interventions may produce the best results in the long run. “Addressing weight loss in the short term and the long term would likely best be accomplished by leveraging as many modalities as possible, and addressing as many variables as possible,” says Pantalone. “The current follow-up observational report did not include a combined intensive lifestyle intervention (ILS) and metformin intervention group, so we do not know whether the two interventions are additive or synergistic for either initial weight loss or for the long-term maintenance of weight loss.” RELATED: 6 Foolproof Ways to Lose Weight for Diabetes and Heart Health
Weighing the Limitations of the Analysis on Metformin and Weight Loss
A corresponding editorial, also published in April 2019 in the journal Annals of Internal Medicine, recognized additional limitations and factors to consider in evaluating the results. While the percentage who maintained weight loss at year 15 was greater in the metformin takers, the hard numbers were bigger for the lifestyle intervention participants — 373 versus 172 in the metformin group. Furthermore, the number of participants in the ILS and placebo groups who received metformin increased over time, wrote editorial authors Leslie Katzel, MD, PhD, and John Sorkin, MD, PhD, with the Baltimore VA Medical Center Geriatric Research Education and Clinical Center and University of Maryland School of Medicine. Also the metformin and placebo groups received some educational training in exercise and dietary advice. Gadde says the study began with participants who were at risk of developing diabetes, so the data cannot be directly applied to treatment of patients with diabetes. “Nevertheless, when taken together with an enormous amount of data gathered from studies of patients with diabetes, our study data is consistent in that one of the benefits of metformin is a small degree of long-term weight loss,” says Gadde. In future studies, researchers would like to investigate whether metformin can help maintain weight loss that is initially achieved with diet, weight loss drugs, or bariatric surgery. One question they’d address, for example, is whether people lose weight initially with low-calorie diets and then take metformin for maintaining that weight loss for several years. No matter what the approach, maintaining a healthy weight is an ongoing and challenging process. “Obesity is a chronic disease,” says Pantalone, “and it must be managed continuously — just as we manage high blood pressure, diabetes, and high cholesterol — in order to help patients lose weight and maintain that weight loss moving forward.” RELATED: 21 Tips for Weight Loss That Actually Work
