GLP-1 Medications and Weight Loss: A Functional Medicine Perspective

<!-- Version: V2 | Updated: 2026-02-12 | Voice: Matt V2 -->

# GLP-1 Medications and Weight Loss: A Functional Medicine Perspective

Dr. Matt Altman, MD | Rooted Health Clinic, Salado, Texas

---

A woman sat down in my office last month — early forties, two kids, works full-time — and before I could even ask how she was doing, she said, "I need you to be honest with me about Ozempic."

She'd been on semaglutide for four months. Lost 22 pounds. Felt great about it. Then her friend stopped hers and gained every pound back in three months. Now she was scared. Was this just a temporary fix? Was she going to be on this medication forever? And why had nobody at her previous clinic talked to her about why she gained the weight in the first place?

Good questions. All of them.

I see some version of this conversation almost every week now. GLP-1 medications have completely changed the weight loss landscape — and I mean that in a genuinely positive way. But there's a massive gap between "this medication helps you lose weight" and "this medication fixes the reason you gained weight." That gap is where most people get into trouble.

What GLP-1s Actually Do (And Why They Work)

I'm not anti-GLP-1. I want to be clear about that upfront because I know the functional medicine world has a reputation for being reflexively against pharmaceuticals. I prescribe semaglutide and tirzepatide regularly. They work.

Here's the thing — they work through some genuinely impressive mechanisms. They act on your brain's appetite centers, slow gastric emptying, improve insulin sensitivity, and reduce inflammation in adipose tissue. The research out of The American Journal of Medicine shows they're doing more than just suppressing appetite — they're actually changing how your fat tissue functions metabolically.

So what's the problem?

About two-thirds of people who stop these medications regain the weight. A major review published in 2025 confirmed this — stopping semaglutide or tirzepatide leads to significant weight regain in the majority of patients. That's not a failure of the medication. That's a sign the underlying problem was never addressed.

Think of it this way. If you take a blood pressure medication and your blood pressure drops — great. But if you stop the med and it shoots back up, we haven't fixed anything. We've managed a symptom. Same principle here.

Why You Gained the Weight in the First Place

This is where I start with every weight loss patient, and it's where most of these conversations go sideways. Before I write a single prescription, I want to understand what's actually driving the problem. Because "you eat too much and move too little" is almost never the full story.

We start with what I call the foundation — metabolic markers and an expanded thyroid panel. Fasting insulin, glucose, HbA1c, lipids. Free T3, free T4, total T3, total T4, TSH. That baseline tells me a lot.

Insulin resistance is probably the single biggest driver of stubborn weight gain I see in my practice. And most of these patients have been told their labs are "normal" because their fasting glucose is 95. Meanwhile their fasting insulin is sitting at 18 and nobody checked it. I calculate something called a HOMA-IR from the insulin and glucose — it's basically a score that tells me how resistant your cells are to insulin. When that number is elevated, your cells can't efficiently take up glucose for energy. You've got fuel in the bloodstream, but your cells can't use it properly. That's like having a full gas tank and a clogged fuel line.

Thyroid is the other big one. Ideal TSH for me is somewhere between 0.3 and 2. A TSH of 3.8 is technically "normal," but if you're sitting in front of me saying you can't lose weight, you're exhausted, your hair is thinning — that's not normal. That's a red flag. And if the baseline thyroid panel shows something off, then I'll go deeper — reverse T3, TPO antibodies, thyroglobulin antibodies. We try not to hammer patients with a thousand dollars in labs on day one. We start with what's most likely to explain the symptoms and escalate from there.

If the foundation doesn't explain what I'm seeing, we keep looking. Cortisol dysregulation from chronic stress — your HPA axis telling your body to hold onto every calorie. Gut dysfunction driving systemic inflammation. Environmental toxins like BPA and phthalates that literally interfere with your body's ability to regulate weight. Low testosterone — yes, in women too.

The point is: there's almost always a reason the weight won't budge. And if we don't find and address that reason, the GLP-1 is just buying time.

The Muscle Problem Nobody Wants to Discuss

Here's something that genuinely concerns me about the GLP-1 gold rush. When you lose weight rapidly — whether through medication, crash dieting, or anything else — you don't just lose fat. You lose lean muscle mass.

The SLIM LIVER study found nearly a 10% decrease in muscle volume in patients on semaglutide. The SEMALEAN study had more encouraging results showing that semaglutide at higher maintenance doses could preserve lean mass while reducing fat mass. So the data is mixed. But here's what's not mixed: if you're losing weight on a GLP-1 without resistance training and adequate protein intake, you are almost certainly losing muscle.

Why does that matter? Muscle is your metabolic engine. It burns calories at rest. Lose a bunch of muscle and you've lowered your basal metabolic rate. So when you stop the medication — and most people eventually do — you now burn fewer calories than before you started. The weight comes back faster. It's a vicious cycle.

This is why I push protein hard with every GLP-1 patient. Minimum 0.8 grams per pound of body weight. And resistance training — not optional. The medication is giving you a metabolic tailwind. If you don't build the engine while you have that tailwind, you'll stall the moment it stops.

How I Actually Use GLP-1s

So do I prescribe them? Yes. But never as a standalone treatment.

Sometimes patients come to me so functionally depleted — exhausted, inflamed, hormonally wrecked — that they can't realistically make the lifestyle changes that would address the root cause. You can't tell someone who hasn't slept well in three years and has a fasting insulin of 25 to just "start exercising and eating clean." They're running on fumes.

This is what I mean when I talk about the pillars of health — sleep, diet, movement, environment, community, mental health. Sometimes a patient is so far behind the curve that we have to jump above those pillars. We intervene medically first to get them functional enough to actually make lifestyle changes. You have to meet people where they are.

GLP-1 medications can be part of that. They buy time and momentum while we:

Fix insulin resistance — through dietary changes, sometimes a ketogenic approach, targeted supplementation. If the baseline labs confirm significant insulin resistance, that becomes a primary target.

Optimize thyroid function — not just "in range" but actually optimal. If the expanded thyroid panel shows something off, we dig deeper and treat accordingly.

Address gut health — because dysbiosis directly impacts how you metabolize food, how inflamed you are, and even your appetite signaling.

Support lean mass — resistance training, adequate protein, monitoring body composition alongside the scale.

The goal isn't to put you on Ozempic forever. The goal is to use it as a tool while we address why your metabolism is broken. Then we taper off as the root causes resolve. Some patients come off entirely. Some stay on a maintenance dose. It depends on what we find and how their body responds.

What I Wish Every Patient Knew

The weight loss industry — and honestly, a lot of mainstream medicine — treats obesity like a simple math problem. Calories in, calories out. Take this shot, lose the weight, problem solved.

But your body isn't a calculator. It's a complex system with hormones, neurotransmitters, inflammatory pathways, gut bacteria, circadian rhythms, and stress responses all feeding into how it handles energy. When that system is dysregulated, willpower and calorie counting aren't going to fix it. And a GLP-1 alone isn't going to fix it either — it's just going to override one piece of the puzzle while the rest stays broken.

The patients I see who lose weight and keep it off are the ones where we identify and address the root cause. Maybe it was undiagnosed insulin resistance that nobody caught because they never checked a fasting insulin. Maybe it was a thyroid that was "normal" by conventional standards but functionally sluggish. Maybe it was chronic gut inflammation driving systemic metabolic dysfunction. Maybe it was all three.

That takes more work than writing a prescription. But it's the only approach that actually lasts.

If This Sounds Familiar

If you're on a GLP-1 and nobody has investigated why you gained the weight — or if you're considering one and want to do it the right way — that's exactly what we dig into at Rooted Health.

We're not anti-medication. We're anti-lazy-medicine. There's a difference.

Give us a call at 254-780-0023 or visit rootedhealthclinic.com to schedule a consultation.

Rooted Health Clinic — 1401 N Stagecoach Rd, Salado, TX 76571

---

References: