A new study from the Endocrine Society has found that people taking weight loss drugs like Ozempic actually started exercising less, not more. The finding has raised concerns about possible muscle loss and longer term health effects among those using the medications.
On average, participants' daily steps fell from about 5,000 to just 4,400 over the course of the study. Their moderate to vigorous physical activity also dropped, from 28 minutes to 22 minutes per day, with all of the activity tracked on the participants' Fitbits.
Dr. Holly Lofton, the director of NYU Langone's Medical Weight Management Program, said it is important to note that the study looked at activity patterns but did not directly measure muscle loss. She said that in her own practice she sees patients who maintain their activity, while others increase or decrease it.
Lofton explained that people trying to lose weight are usually encouraged to eat as little as they can and exercise as much as they can. But because the GLP-1 drugs produce so much fat loss, she said, many patients find they can exercise less and still get results, so they may not do as much activity as they did before.
She said that fat mass makes up the majority of the weight lost on the drugs, along with some muscle. According to an analysis of people taking medicines like Wegovy and Ozempic, the larger fat loss compared with muscle loss can leave patients proportionally more muscular than when they started. Strength, she added, depends on activity, so resistance training and lifting weights can help keep it up.
Lofton also addressed reports of a so-called Ozempic personality, where some people feel less enjoyment of various things, which she described as anhedonia. She said it can be a side effect worth discussing with a prescriber in order to lower the dosage, noting that only a small share of her patients, around one percent, experienced it, while most actually enjoyed their exercise more.