The number on the scale is lying to you
Weight loss and muscle loss can look identical from the outside. Here's how to tell which one is actually happening- and why it matters more than anything else on your GLP-1 journey.
Three months ago, I heard from a woman who had lost 14 kilograms on her GLP-1 medication. By every external measure she was succeeding. Her clothes were looser. Her doctor was pleased. Her family kept telling her how great she looked.
She felt terrible.
Exhausted in a way sleep didnât fix. Weaker on the stairs that she used to be. A sense that something was quietly going wrong underneath the number that everyone kept celebrating.
She wasnât imagining it. Something was going wrong. And it had been going wrong for months while the scale moved in the right direction.
The problem with weight as your only metric
When you lose weight, you are not losing one single thing. Youâre losing a combination of fat mass, muscle mass, water, and - in a well-constructed nutrition approach- it will be mostly fat. The proportion of each depends on what you eat while the weight comes off.
On a GLP-1 medication with no nutritional strategy, that proportion tilts heavily toward muscle loss. Not because the medication causes it directly, but because the medication reduces your appetite across the board and most women, eating less overall without a deliberate protein focus, are not eating nearly enough to protect their lean tissue.
The scale cannot tell you what youâre losing. It can only tell you that youâre losing.
This distinction is everything. A woman who loses 15kg with good muscle preservation has transformed her body composition, protected her metabolism and set herself up for long-term weight management. A woman who loses 15kg with significant muscle loss has a slower metabolism than when she started, a higher risk of weight re-gain when she reduces her medication and a body that is functionally weaker than it was before.
Same number on the scale. Completely different outcomes.
What muscle loss actually feels like
It rarely announces itself dramatically. It tends to show up as:
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Fatigue that isnât explained by poor sleep.
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Feeling noticeably weaker doing things that used to be easy- carrying groceries, climbing stairs, getting up off the floor. A sense of physical fragility that feels disproportionate to the amount of weight youâve lost.
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Clothes fitting differently than youâd expect- looser in some places, but not in the places youâd hoped.
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Hair loss is another signal. When the body is under nutritional stress, it deprioritises hair growth in favour of more critical functions. Significant hair shedding at three to six months into a GLP-1 is often a sign of protein and micronutrient insufficiency, not the medication itself.
The markers that actually matter
I work with my clients to track four things alongside scale weight:
How your clothes fit- specifically, are you losing from your limbs (muscle) or your midsection (fat)?
Your grip strength- a crude but surprisingly sensitive measure. Can you open jars as easily as six months ago? Carry the same load of shopping?
Your energy on injection day- some fatigue in the 24-48 hours after injection is normal. Persistent fatigue throughout the week is not, and is often nutritional rather than medication related.
Your protein intake- I keep coming back to this because it is the single most actionable lever. Most women I see are hitting 40g - 60g per day. The evidence-based target for muscle preservation on a GLP-1 is 1.2g - 1.6g per kilogram of goal body weight. For a 75kg woman, the gap between what they are hitting and what they should, be can be enormous.
Your personal risk profile
Not every woman on a GLP-1 carries the same muscle loss risk. Factors like menopausal status, current protein intake, activity level, and how long youâve been on the medication all affect how urgently you need to act on this.
Iâve put together a Muscle Risk Checklist- the same one I use in my program- that lets you asses your personal risk across four categories: hormonal, dietary, activity, and medication factors. It takes about three minutes to complete and tells you clearly where to focus your attention.
If you score in the moderate to higher risk range, the most important thing you can do this week is not change your medication, not add a supplement, not panic. Itâs to get deliberate about protein. Everything else builds from there.
Next week Iâm going to give you something that most woman never get from their Dr- a complete guide to the blood markers that tell the real story of whatâs happening in your body on a GLP-1, and the exact script to use to ask for them.
Every time I talk to women about speaking to their Drs about their blood tests the response is always the same, âI donât understand what they say.â Getting your Dr to clearly explain your blood test results and what the numbers actually mean is critical for you to become a driver of your own health.
đ THIS WEEKâS SUPERMARKET FIND đ
Woolworths Australian Rolled Oats 750g $1.60
Oats are not a protein food but they earn a place in the GLP-1 nutrition strategy for a different reason. Half a cup of rolled oats delivers approximately 5g of soluble fibre, which is one of the most important nutrients for gut motility on a GLP-1 (constipation is real, and largely preventable). They also have a low glycaemic impact relative to most breakfast cereals, which matters for blood sugar stability. The key is what you add: stir a scoop of unflavoured Whey Protein Isolate (WPI) protein powder through the cooked oats and youâve added 20-30g of protein to a meal that would otherwise delivered almost none. The Woolworths Rolled Oats are an affordable, minimally processed, good quality product. Donât overthink breakfast. This, with protein powder, berries and some honey, is genuinely enough.
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đ± THIS WEEKâS VITALITY STEP đ±
Download the Muscle Risk Checklist and score yourself honestly.
Donât skip this because you think you already know your risk level. The women I work with who are most surprised by their score are almost always the ones who thought they were doing fine. The checklist takes three minutes. Your score will tell you exactly which part of your nutrition approach needs the most attention right now. That clarity is worth more than another week of vague good intentions.
đReady to go deeper?
The Vitality Protocol is my online program for women on GLP-1 medications- covering muscle-first nutrition, practical supermarket strategies, and rebuilding joy beyond food. Click Here.
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