The Doctor Who Became the Patient: Part 3
The Hidden Cost of Weight Loss
A physician’s first-person account of GLP-1 medications, a shocking Full Body DEXA scan, and the Achieve system that changed everything.
Alex Foxman, MD, FACP, ABOM — Founder, Achieve Health and Weight Loss
7-minute read
THE PROBLEM NO ONE TALKS ABOUT
Dr. Alex Foxman, MD, FACP, DABOM
Weight loss can look like progress. Sometimes, it is also a trade.
This is not unique to GLP-1 medications. Any significant weight loss — through diet, exercise or medication — can lead to muscle loss if it is not managed well.
That includes GLP-1s. These medications are powerful, life-changing tools. The issue is not the medication itself — it is using it without a plan.
When appetite drops quickly, food intake often drops with it. If protein, strength training, and recovery do not keep up, muscle can drop too.
Standard Weight Loss
Most fat loss is not pure fat loss. Some muscle usually comes with it.
That is true with or without medication.
Weight Loss on GLP-1s
The appetite effect is real. So is the risk of under-eating protein and losing muscle faster than intended.
Without a deliberate plan, the scale can move in the wrong direction for the wrong reasons.
Weight Regain
When weight comes back, it is rarely a clean return.
Fat tends to return faster than muscle, which can make each cycle worse.
Weight loss without a plan can cost you muscle, metabolism, and years of health.
What Muscle Loss Really Means
Muscle is not just about looking fit. It helps support metabolism, steadier blood sugar, and the strength you need for everyday life.
Lose too much of it, and the effects may start quietly — then become hard to ignore.
Less Stability
Weaker muscles make balance and movement harder, which raises fall risk.
Slower Metabolism
Muscle burns more energy than fat, even at rest. Lose muscle, and your calorie burn can drop.
Worse Blood Sugar Control
Muscle is a major place where the body uses glucose. Less muscle can mean poorer insulin sensitivity.
Frailty Over Time
Too little muscle can chip away at strength, independence, and resilience as you age.
Bone Loss
When muscle loading drops, bone often follows. Less stress on the skeleton means weaker bones over time.
Long-Term Risk
Low muscle and low strength are linked with worse health outcomes later in life.
The Good News: This Is Preventable
Muscle loss is not inevitable. With the right plan, you can reduce it — and often reverse it.
The formula is simple: enough protein, enough resistance training, and enough consistency to make them stick.
High-Protein Nutrition
Protein gives your body the raw material it needs to preserve muscle.
When appetite is lower, protein has to be more intentional, not less.
Progressive Resistance Training
Muscle keeps what you use. If you challenge it, your body has a reason to hold onto it.
In my own case, the right plan helped turn weight loss into lean-mass gain.
What the Research Keeps Showing
STEP 1
Semaglutide lowered weight, but lean mass also fell.
STEP 2
Tirzepatide showed the same pattern: less fat, but still some lean loss.
STEP 3
Across multiple studies, a meaningful share of weight lost came from lean tissue.
STEP 4
In real-world care, the trend is better with the right support — but not perfect without it.
And Then There's Bone
Bone matters here too. As weight comes off, the skeleton has less load to carry.
Over time, that can mean weaker bones and a higher fracture risk. So this is not just about getting smaller — it is about what you keep while you get there.
Sarcopenia. Osteopenia. Two words I never expected to associate with my own body.
Stay Tuned for Part 4: Two Real Risks. One Body.
About The Author
Alex Foxman, MD, FACP, DABOM
Achieve Health & Weight Loss Founder & Medical Director
Dr. Alex Foxman, MD, FACP, DABOM, is a distinguished leader in weight management, internal medicine, and preventive care, renowned for his groundbreaking contributions to the medical, health and wellness industries. As one of the few physicians in the nation—less than 0.5%—to hold dual Board Certifications in Obesity Medicine and Internal Medicine, Dr. Foxman exemplifies the pinnacle of medical expertise and dedication.