The popular weight loss drugs that have shown dramatic results in celebrities like Oprah and Sharon Osbourne are powerful appetite suppressants. When you eat fewer calories than you burn, your body loses fat. But experts warn that you also lose muscle. In fact, it is estimated that a quarter to a third of the weight loss while taking these medicines is lean body mass, and most of that is muscle.
According to MSN, this can be dangerous for people like the elderly, who already have less muscle to spare, making them more vulnerable to falls. It’s also potentially troublesome for dieters with low muscle mass who become super responders to the drugs and lose significantly more than the normal 15 to 20% of their body weight.
“I watch them very carefully,” says Dr. Robert Kushner, an obesity specialist from Northwestern University, who was also an investigator in a trial for one of the weight loss drugs. Kushner says that muscle cells are not only major consumers of energy, but they also influence insulin sensitivity and absorb 80% of the glucose that accumulates in the blood after a meal. Losing too much muscle could also affect metabolic function.
The new weight loss drugs like Wegovy and Zepbound, also called Ozempic and Mounjaro when they are prescribed for diabetes, cause more muscle loss than diet and exercise alone, says MSN, but their effect is on a par with bariatric surgery. Lifestyle changes can blunt the loss of muscle and experts recommend that people who take these drugs eat a high protein diet and strength train.
The difficulty with this advice is that people often experience fatigue when on the medication, so exercising isn’t on their radar. And since the drugs suppress appetite, eating more protein may not be attractive, either.
Researchers are now investigating ways to pair the weight loss drugs with a second muscle-enhancing drug. Such a combination could allow patients to lose fat and gain muscle at the same time. One of the drugs being studied is an antibody called bimagrumab which was originally tested to treat muscle-wasting disease. Several pharmaceutical and biotech companies are investigating different muscle-building antibodies and pairing them with semaglutide, the active ingredient in Wegovy and Ozempic.