Typically, rapid weight loss can result in the loss of lean muscle and bone. Slower weight loss tends to preserve muscle mass, which may make it easier to keep the weight off long-term. 

While many of us tend to only focus on the number on the scale while trying to lose weight, not all weight loss is good for our health. Losing lean muscle and bone along with body fat, will not make you healthier. In fact, for many older adults, the combination of low lean muscle with a high body fat percentage can increase the risk of many metabolic diseases regardless of how much they weigh. 

GLP-1 medications are associated with a rapid and significant reduction in body weight. But what impact do these medications have on lean muscle and improving overall health? 

GLP-1 and Lean Muscle

Animal studies have found that GLP-1 medications may help protect against muscle loss when compared to other forms of weight loss. However, the research is still limited on the impact that GLP-1 medications have on the loss of lean body mass in humans using them for weight loss. 

A 2021 trial found that lean body mass accounted for 39% of the total weight lost in subjects using GLP-1 medications. But, because so much body fat was lost in addition to the lean body mass, the subjects still ended up with an increased proportion of lean body mass when compared to total body mass. Overall, the weight loss was still beneficial.

Additionally, researchers note that the loss of lean muscle mass is in line with the muscle loss experienced with other weight loss methods. 

How to Preserve Lean Muscle

If you want to avoid losing too much lean muscle while taking a GLP-1 medication there are a few things that can help. These include adding resistance training to your exercise routine and eating a high protein diet. 

Try to include resistance training twice a week in addition to 150 minutes of cardiovascular exercise per week. 

Aim to eat at least .75-1 gram of protein per pound of your ideal body weight. This means that if your ideal weight is 150 pounds, you should try to eat 112-150 grams per day.

Finally, while it may be appealing to lose weight rapidly while on these medications, consider losing slowly. Don’t increase your dose if you are consistently losing 1-2 pounds per week. Speak to your provider about your ideal dose and when you should move up. 


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