No matter how you lose weight, you’re also probably shedding muscle. Photo / Getty Images
There are few constants within the world of weight loss, but one concept holds up: no matter how you lose weight — through restrictive eating, bariatric surgery or the new, buzzy class of injectable medications like Ozempic and Wegovy — you’re also probably shedding muscle.
That’s particularly aconcern for older adults, obesity medicine experts say. The more muscle someone older than 65 loses, the greater their risk of becoming frail or suffering a fracture or fall (which can be fatal in older adults). It is crucial for older adults to maintain muscle mass so that they can stay mobile and independent.
Muscle mass naturally dwindles with age. A 70-year-old, for example, will probably have less muscle and more fat than a 30-year-old with the same body mass index, said Dr Scott Hagan, an assistant professor of medicine at the University of Washington who has studied obesity. When people lose large amounts of weight in a short time, such as while taking a drug like Ozempic, the loss of muscle mass can be drastic, with stark ramifications for health.
We know very little about how older adults in particular fare on these medications, said Dr Janice Jin Hwang, chief of the division of endocrinology and metabolism at the University of North Carolina School of Medicine. Clinical trials on semaglutide, the active ingredient in Ozempic and Wegovy, have typically enrolled people in their 40s and 50s.
“I’ve struggled with this when counselling patients,” Hagan said, adding that he had concerns about clinicians prescribing these kinds of medications “with someone who’s 75 just because their BMI’s 40″.
In clinical trials of semaglutide, people 65 and older were more likely to experience gastrointestinal side effects such as nausea and vomiting than younger people. They were also more likely to stop taking the medications because of side effects in general.
Fatigue is a common side effect of these drugs, and can be even more pronounced in older adults. That can be the result of not eating enough while on the medications, but when people lose a large amount of weight, their blood pressure can also dip, Hagan said, which can make them feel dizzy and weary.
High blood pressure is common in older adults, but they are also susceptible to orthostatic hypotension, a sudden drop in blood pressure when standing up from sitting or lying down. The weight loss that comes with these medications can exacerbate that low blood pressure and make symptoms like feeling faint or lightheaded more pronounced.
People who already have or are predisposed to osteoporosis — which affects nearly 20 per cent of women 50 and older in the United States — need to be careful with these medications, Hagan said, because rapid weight loss can make their bones less dense. Our bones are almost constantly changing, Hagan said, and weight loss reduces the mechanical force we put on our bones, which can lead to bone loss in some people. Weight loss may also impair calcium intake and absorption, he said.
Reducing muscle mass means older adults may lose strength and stamina, too, said Dr Andrew Kraftson, a clinical associate professor at Michigan Medicine. This can make it more difficult to carry groceries or walk up stairs, for example.
“The picture of frailty would be someone with osteoporosis, prone to fall, who has fractures, who’s unable to do a lot of their activities,” he said. “We’re trying not to do that.”
Protective measures
For anyone taking these medications, but especially for older adults, it’s critical to regularly engage in strength training exercises, such as lifting weights, and to consume enough protein to buffer against shrinking muscle. Hagan typically recommends that patients taking a medication like Wegovy or Ozempic get at least 100 grams of protein per day — which can be challenging, he admitted, because the medications suppress appetite.
Doctors may also prescribe lower doses of the medication for adults older than 60, Kraftson said, to minimise side effects and slow weight loss.
“Folks should reorient their expectations and not try to get to the body weight they were when they were 18,” Kraftson said.
Every week, though, patients tell him they want just that — “regardless of their age”, he said.