New weight loss drugs can cause decline in skeletal muscle mass: Lancet study

Amid the growing use of weight loss medications, a new study has raised concerns about declining skeletal muscle health caused by the popular drugs.

In a recent commentary published in The Lancet journal, researchers from the US and Canada highlighted the critical importance of skeletal muscle mass in the context of medically induced weight loss, particularly with the widespread use of GLP-1 receptor agonists.

While the drugs have shown extreme potential in treating obesity—a precursor for many diseases like diabetes, hypertension, and cancer—they can also lead to substantial muscle loss as part of the weight loss process, argued researchers from Pennington Biomedical Research Center in the US, Universities of Alberta and McMaster in Canada.

They noted that muscle loss—measured by decreases in fat-free mass—can account for 25 to 39 per cent of total weight lost through the 36 to 72 weeks. The role of skeletal muscle is not only for maintaining physical strength and function but it is also crucial for metabolic health and regulation of the body’s immune system.

The team found that GLP-1 receptor agonists lead to significantly larger muscle decline than with a non-pharmacological caloric restriction diet or normal ageing. This, the researchers said, “could lead to unintended negative health consequences”.

People with poor muscle mass have decreased immunity, and are at increased risk of infections, poor glucose regulation, and other health risks.

Further, the researchers noted that muscle loss caused by weight reduction can also worsen sarcopenic obesity—prevalent among individuals with obesity, and contributes to cardiovascular disease and higher mortality rates.

Dr. Steven Heymsfield, professor of metabolism and body composition at Pennington, called on people going for weight loss drugs to be “mindful of the side effects”. He added that, while on the medications people are “eating less and not getting the appropriate amount of dietary vitamins and minerals”.

An adequate amount of protein along with an optimum amount of exercise should be explored along with the medications, suggested the researchers.