The most concerning side effect of GLP-1 medications like Ozempic and Zepbound isn’t nausea, diarrhea, or stomach discomfort.

Instead, it’s muscle loss—a condition that can have serious consequences if not proactively managed.

As a board-certified endocrinologist, I can assure you that opting for GLP-1 treatment is far from taking the ‘easy way out.’ It requires significant effort and commitment.

I’ve guided countless patients to achieve health milestones they once deemed unattainable, and here’s how they succeeded.

First, it’s crucial to recognize that it’s not the medication itself that harms your muscles. Any form of rapid weight loss, regardless of the method, can lead to muscle mass reduction.

But it’s even more crucial to preserve muscle when you are on a GLP-1 because you will eat less while taking the medication.

And when you eat less (especially without prioritizing the nutrients your muscles need), your body will pull muscle from its reserves.

Muscle is easy for your body to break down. If you’re not feeding it and challenging it, your body sees it as expendable.

Jessica Simpson’s rapid weight loss (before, left, and after, right) – which she denies is a result of GLP-1s – has caused what some describe as Ozempic face

Contrary to popular belief, choosing GLP-1 treatment isn’t the ‘ easy way out’ – it takes real work

Lose too much, and you won’t just have an unfortunate case of the much-maligned Ozempic face; it’ll actually slow your metabolism, reduce your functional strength, and even increase your risk of future disease. 

As we get older, muscle loss also reduces mobility and increases the risk of falling.

That’s why ensuring you get enough protein in your diet, combined with strength training, is a non-negotiable part of your treatment.

But exactly how much protein do we need?

The dietary guidelines differ depending on who you ask.

The United States Department of Agriculture recommends 0.8g per kg of body weight per day. This works out at around 54g for a 150 pound person.

Here’s the catch: Most official guidelines are designed to prevent deficiency, not to promote optimal health. These guidelines won’t help you preserve or build muscle to thrive as you age.

Many experts, including myself, now recommend almost doubling that – to between 1.2g and 2g per kg of body weight for active individuals, older adults, and those trying to lose weight or preserve muscle (about 80g to 135g for someone weighing 150 pounds).

Kelly Osbourne (in 2012, left, and last month, right) – she says her rapid weight loss is a result of taking Ozempic and grieving the death of her father

Scott Disick (photographed in 2016, left) faced a public outcry over his use of Mounjaro earlier this year, with fans worried about his gaunt appearance (right)

In clinical practice, I’ve found that a minimum of 100g per day is typically necessary just to hold on to existing muscle mass during GLP-1 treatment.

Reaching these protein goals can be hard work: it’s a lot more than most of us are used to eating.

And it isn’t just about knowing what to eat; it’s about when, how often, and in what form. Logistics, not motivation, tend to be the biggest stumbling block.

To help you manage these, here is the protein game plan I give my patients, with seven simple guidelines to follow:

1. Start early

Getting a solid dose of protein within the first hour or so of waking up gives you a head start and helps distribute your intake across the day, which is much easier on your appetite than trying to cram it all in at the end.

If you put creamer or milk in your coffee, add a scoop of unflavored or flavored whey protein instead.

2. Count no more than 30g of protein per meal

I once had a patient who was using two servings of protein powder at a time. Double the serving, double the protein, right?

Unfortunately, no. He may have been consuming twice the recommended amount, but his body was absorbing only half of it. Research shows that 30g is about the maximum amount of protein your body will direct toward muscle preservation/development at any given meal.

Rocio Salas-Whalen has helped thousands of patients reach health goals they once thought impossible. Her new book, Weightless (right) explains how they did it

Don’t bother doubling up the protein in your shake – research shows 30g is the maximum amount of protein your body will direct toward muscles at any given time

Aim to space your daily protein intake across four portions, each with around 25g to 30g of protein at a time.

If your meal goes over 30g, that’s fine, but only count 30g toward your daily total.

3. Understand your macros

I’ve had patients tell me they’re hitting their protein target, but their body composition scan shows that they’re still losing muscle mass.

Nine times out of ten, the discrepancy happens because they’ve underestimated what 30g of protein looks like.

It could be 4 ounces of cooked chicken breast or lean ground beef (a portion about the size of the palm of your hand); 5 ounces of cooked salmon; or 5 to 6 ounces of tuna (a standard-sized can).

In the dairy and eggs aisle, consider 1 1/4 cups cottage cheese or 5 (yes five) large eggs.

For vegetarians, 30g of protein is contained in 3/4 cup of tofu; 2 cups cooked lentils or chickpeas; or 3 3/4 cups of cooked quinoa.

About one palm-sized portion of cooked chicken contains 30g of protein

A standard size tin of tuna is also the equivalent of around 30g of protein

It would take a mighty five eggs to provide enough protein in one meal

Snack on Greek yogurt with pumpkin seeds (30g of protein), a cup of cottage cheese (25g), or a half-cup each of edamame beans and almonds (25g) to supplement the protein from your meals.

4. Give your body time between meals

Space your meals at least three to four hours apart. Protein is very filling; if you don’t allow enough time between supplementation and meals, you won’t be able to consume the amount of protein you need in a day.

5. Get the protein off your plate first

This will ensure that you meet your target intake even if your appetite dips midway through your meal.

6. Drink protein shakes

They’re a great way to supplement – many patients are successful with keeping to a roughly 50/50 ratio of protein shakes to meals. This ensures that you have a quick and easy way to load up on protein but don’t end up feeling undernourished or experiencing low energy from lack of food.

However, as you plan your day, remember not to have any shakes too close to meals; you don’t want a shake making you feel full when it’s time to eat.

7. Invest in a body composition scale

A regular bathroom scale will not give you an idea of whether the weight you’re losing is fat, muscle, or a combination of the two.

Your at-home device doesn’t need to be top of the line, just consistent, and will help you track changes in your muscle mass and fat between appointments. 

If it’s not economically feasible for you to purchase one for home use, check to see if one is available at a gym near you.

Excerpted from Weightless by Rocio Salas-Whalen, MD (available to pre-order). Copyright © 2025 by Rocio Salas-Whalen, MD. Excerpted by permission of Rodale Books. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.