Preserve muscle while on GLP-1s: A dietitian’s guide to success

Dallas (KDAF) — There’s been a lot of buzz lately about GLP-1 medications such as semaglutide and tirzepatide, sometimes called “weight loss shots.” However, according to registered dietitian Meridian Zerner at Cooper Clinic in Dallas, these prescriptions work best alongside healthy habits.

“GLP-1s are not magic wands, and they’re definitely not for everyone,” Zerner said. 

“They’re a medical tool for people whose health is significantly affected by extra weight or high blood sugar, not for casual or cosmetic weight loss.”

GLP-1 stands for glucagon-like peptide-1, a hormone the body naturally produces in the gut after eating. It helps regulate blood sugar, slows digestion and signals fullness to the brain. Prescription GLP-1 medications mimic this hormone, helping patients feel satisfied sooner, reduce cravings and improve blood sugar control.

Zerner noted that potential side effects, such as muscle loss, make medical supervision essential. 

She sees clients regularly who are on a GLP-1 medication and noted at least 12% of Americans are on one.

“There are no set protocols yet, but we do know that three things make the biggest difference: protein, fiber and movement,” Zerner said.

She explained that people taking GLP-1 medications often eat less overall, which can put muscle at risk. To counter that, she recommends aiming for about 30 grams of protein per meal to preserve lean mass, support metabolism and maintain strength.

Fiber is another priority, Zerner said, because it supports gut health, satiety and steady blood sugar levels. Foods such as leafy greens, beans, berries, nuts, seeds and whole grains are good choices.

And regular movement, especially resistance training, is critical for keeping muscle, lifting mood and sustaining weight loss over time.

“Even walking counts,” Zerner said. “These lifestyle habits matter regardless of whether you stay on the medication long term.”

Ultimately, Zerner emphasized that while GLP-1s may be effective for some, they work best in combination with consistent nutrition and exercise.

If you’re interested in booking a consultation with Cooper Clinic , visit cooperaerobics.com.