How I Lost Fat and Gained Muscle on Semaglutide

After sharing my weight loss journey using GLP-1 medications like semaglutide a few years ago, I wanted to follow up with my experience focusing on body composition—specifically, how I was able to lose fat while gaining muscle. Over a four-month period from November 1, 2024, to March 12, 2025, I tracked my progress using a 3D body scanner and saw the following changes:

• Fat Loss: 8.2 pounds
• Lean Muscle Gain: 1.1 pounds

This was a significant shift, as many people on GLP-1 medications struggle to maintain muscle mass while losing weight. In fact, there are several clinical trials showing that anywhere from 40-60% of weight loss is muscle, not fat! 

Here’s how I optimized my body composition while on semaglutide:

1. Prioritizing Resistance Training

Lifting weights twice a week was non-negotiable. My goal was to progressively overload my muscles by increasing weight or reps every 2 weeks. This helped stimulate muscle growth and prevent muscle loss, which is crucial when in a calorie deficit.

2. Combining Zone 2 and HIIT Training

I incorporated two days of cardiovascular exercise—one focused on Zone 2 training (steady-state, moderate-intensity cardio) and one on high-intensity interval training (HIIT). This balance allowed me to burn fat efficiently while maintaining cardiovascular fitness without compromising muscle mass. I accomplished this by taking classes at Orangetheory. 

3. High Protein Intake

I made sure to consume at least 1 gram of protein per pound of lean body mass daily. Protein is essential for muscle repair and growth, especially when in a calorie deficit. By prioritizing protein, I ensured my body had the necessary building blocks to maintain and even build lean muscle tissue.

4. Tracking Calories and Macros

I carefully monitored my caloric intake to ensure I wasn’t losing weight too rapidly. A safe and sustainable fat loss rate is around 0.5 to 1 pound per week. Eating too little would increase muscle loss, so I adjusted my intake based on my performance in the gym. If I noticed a decline in strength or reps, I increased my calories slightly to maintain performance.

5. Monitoring Progress with Data

I used a 3D body scanner to track body composition changes every 3-6 months. This helped me ensure that my weight loss was coming primarily from fat rather than muscle. In addition, I tracked my gym performance—if my lifts started declining, it was a clear sign to adjust my diet or training intensity.

Key Takeaways

• Resistance training is critical to maintaining muscle on semaglutide.
• A combination of Zone 2 and HIIT cardio maximizes fat loss while preserving lean mass.
• High protein intake is essential for muscle preservation.
• Monitoring calorie intake prevents excessive muscle loss.
• Tracking body composition ensures fat loss is happening in a healthy way.

For anyone on a GLP-1 medication looking to optimize body composition, these strategies can help you lose fat while building or maintaining muscle. The key is to be intentional about strength training, nutrition, and tracking progress over time.

What has your experience been like with weight loss and muscle maintenance on semaglutide? Share your thoughts in the comments!

Image from the 3D body scanner showing a 17.2% decrease in fat over 4 months.

Image from the 3D body scanner showing a 8.2 pounds decrease in fat over 4 months.

Image from the 3D body scanner showing a 5.2% increase in lean muscle over 4 months, corresponding to 1.1 pounds.

Image from the 3D body scanner showing a 2.3 inch or 6.6% decrease in waist circumference over 4 months.