The Single Biggest Nutrition Mistake My Patients Make on GLP-1’s

By Kevin D. Huffman, DO

AmBari Nutrition

. https://www.ambarinutrition.com

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The Single Biggest Nutrition Mistake My Patients Make on GLP-1’s

After years of treating patients on GLP-1 medications, I can tell you the single biggest mistake I see is not about eating too much or choosing the wrong foods. It is failing to protect their muscle mass.

These medications are extremely effective. Patients eat less, lose weight quickly, and see encouraging changes on the scale. I watch them light up at every weigh-in.

But the scale does not tell the whole story.

A significant portion of that weight loss can come from muscle, not fat, if you are not deliberate about your nutrition and exercise. And that is a problem most patients do not see coming.

Why Muscle Loss Happens on GLP-1 Medications

Here is what I explain to every new patient starting a GLP-1. These medications work by dramatically reducing your appetite. You eat less. Your body needs to find energy somewhere, and it does not just pull from your fat stores. It breaks down muscle too.

Your muscle is your metabolic engine. It burns calories even when you are sitting on the couch. But your body does not care about that when it is looking for quick fuel. Muscle is actually easier to break down than stored fat, so without the right nutrition and stimulus, your body will sacrifice it.

Research shows that up to 40 percent of weight lost during calorie restriction can come from lean muscle mass if you do not take steps to prevent it. [1] That is a staggering number, and I have seen the consequences firsthand. Patients who look thinner but feel weaker. Patients who hit their goal weight but are exhausted all the time. That is not the outcome any of us want.

I also have honest conversations with my patients about what happens after they stop the medication. The STEP 1 trial showed that participants regained approximately two-thirds of their prior weight loss within one year of stopping treatment. [2] That is not meant to scare anyone. It is meant to make the case that what you do while on the medication matters enormously.

Why Muscle Loss Makes Weight Regain More Likely

This is the part I wish more patients understood before they started treatment, not after.

When you lose muscle, your metabolism slows down. You finish treatment weighing less, but your body is now burning fewer calories than it was before you started. So when normal eating resumes, the math works against you. Fewer calories burned plus more calories consumed equals weight gain.

I have seen this pattern too many times. Patients who did everything right on the scale but did not protect their muscle end up regaining weight and feeling like they failed. They did not fail. They just were not given the full picture.

You did not just lose fat. You lost your metabolic engine. And rebuilding it is much harder than preserving it in the first place.

How to Prevent Muscle Loss While Taking GLP-1 Medications

The good news is that this is preventable. I give every one of my patients the same three rules, and the ones who follow them consistently get the best long-term results.

1. Consume Adequate Protein Every Day

I tell my patients to aim for approximately 100 grams of protein per day. That sounds like a lot when your appetite is practically nonexistent, and honestly, it is. Most patients cannot get there through food alone.

This is where protein supplementation becomes important. A high quality protein supplement delivers essential amino acids in a small volume, which matters when your stomach capacity is limited. Not all supplements are created equal though. You want something with high bioavailability, a complete amino acid profile, and low sugar. This is exactly why I developed AmBari Nutrition, because I saw too many of my patients relying on products that were not designed for their situation.

Without sufficient protein, muscle loss accelerates. It is that simple.

2. Eat Protein First at Every Meal

This is the same rule I give my bariatric surgery patients, and it applies just as much on GLP-1 medications.

When you can only eat a small amount, the order matters. Protein goes first. Always. If you fill up on bread or rice before touching your chicken, you have wasted your limited stomach space on calories that will not protect your muscle.

If you get full after five bites, those five bites need to be protein. This is a simple behavioral shift, but it is one of the most impactful changes my patients make.

3. Perform Resistance Training Weekly

I cannot stress this enough. Your body will not hold onto muscle it does not think it needs.

Resistance training sends your body a signal: this muscle is being used, do not break it down. Without that signal, muscle loss is inevitable no matter how much protein you eat.

I tell my patients to aim for resistance training at least two to three times per week. It does not have to be extreme. Bodyweight exercises, resistance bands, light weights — all of it counts. But walking alone is not enough. Walking is great for your heart, but it will not save your muscles.

The Real Goal Is Metabolic Protection

GLP-1 medications are powerful tools. I have seen them change lives. But the patients who get the best long-term results are not the ones who lose the most weight. They are the ones who lose weight while keeping their muscle intact.

The goal is not just to be smaller. The goal is to come out the other side with a metabolism that can sustain your new weight, with the strength and energy to live the life you want.

Patients who prioritize protein and resistance training build that foundation. Patients who do not often find themselves back where they started.

Protecting your muscles is not optional. It is the difference between temporary weight loss and lasting metabolic health.

References

[1] Neeland IJ, Linge J, Birkenfeld AL. Changes in lean body mass with glucagon-like peptide-1-based therapies and mitigation strategies. Diabetes Obes Metab. 2024;26 Suppl 4:16-27. doi:10.1111/dom.15728

[2] Wilding JPH, Batterham RL, Davies M, et al. Weight regain and cardiometabolic effects after withdrawal of semaglutide: The STEP 1 trial extension. Diabetes Obes Metab. 2022;24(8):1553-1564. doi:10.1111/dom.14725