If You're on Ozempic, This Is the One Thing You Need to Know About Protein
GLP-1 medications have changed the conversation around weight, health, and metabolism in a way that very little else has. If you are taking semaglutide (Ozempic or Wegovy) or tirzepatide (Mounjaro or Zepbound), the chances are it is working. Appetite is down. Food feels different. The scale is moving.
But there is something most prescribers are not talking about. And it matters more than almost anything else you can do while you are on this medication.
Protein. Specifically, how much you are eating, and why it is almost certainly not enough.
Here Is What Is Actually Happening
GLP-1 medications work by mimicking a gut hormone that suppresses appetite, slows gastric emptying, and increases feelings of fullness. They are remarkably effective. And that is precisely where the problem begins.
When appetite drops significantly, total food intake drops with it. And when total food intake drops, protein is usually the first casualty. Not intentionally. Just because you are eating less of everything, including the foods your body relies on most.
Research presented at the European Congress on Obesity in 2025 found that 88% of people on GLP-1 medications were eating below recommended protein levels, averaging just 0.6g per kilogram of body weight per day. At that intake level, research shows that up to 40% of weight lost can come from lean muscle mass rather than fat. (ECO 2025)
Read that again: up to 40% of what you are losing may not be fat. It may be muscle.
Why Muscle Loss Is a Bigger Deal Than It Sounds
Muscle is not just about how you look or how strong you feel, though both of those matter. Muscle is metabolically active tissue: it burns energy even at rest, which means preserving it is central to sustaining the metabolic benefits of weight loss long term.
A study published in The Lancet Diabetes and Endocrinology (Prado et al., 2024) found that GLP-1 therapies can result in lean mass losses comparable to those seen in certain medical conditions, with reductions of up to 13.9% in lean mass recorded in some participants. (Prado et al., The Lancet, 2024)
A 2025 study presented at ENDO 2025, the Endocrine Society's Annual Meeting, specifically flagged women and older adults as being at higher risk of muscle loss compared to other GLP-1 users. (Haines M. et al., ENDO 2025)
For women especially, this is significant. We already face accelerated muscle loss during perimenopause and menopause due to declining oestrogen. Combining that with inadequate protein on a GLP-1 medication creates a compounding risk that is not getting nearly enough attention.
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What the Research Now Recommends
A joint advisory from four major US medical societies (the American College of Lifestyle Medicine, the American Society for Nutrition, the Obesity Medicine Association, and the Obesity Society) now explicitly recommends 1.2 to 2.0g of protein per kilogram of adjusted body weight per day for anyone on GLP-1 therapy. (Mozaffarian et al., American Journal of Lifestyle Medicine, 2025)
To put that in context: most GLP-1 users are currently eating around 0.6g/kg. The recommendation is two to three times that amount.
This is not a minor adjustment. It is a fundamental shift in how protein needs to be prioritised when using these medications.
The Practical Challenge
Here is the honest truth about eating enough protein on a GLP-1 medication: it is hard. Your appetite is suppressed. You feel full after a few bites. The idea of sitting down to a substantial meal often feels genuinely unappealing.
Which means every bite you do take needs to count.
This is where the type and quality of food matters more than it ever has. When you can only manage small amounts, those small amounts need to be protein-dense.
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What to Prioritise
Here are the highest-protein, lowest-volume foods to lean on when your appetite is limited:
• Eggs (6g each): scrambled, poached, or as a frittata with vegetables
• Greek yoghurt (17g per 170g): pair with a small handful of nuts for healthy fats
• Cottage cheese (14g per half cup): mix into smoothies or eat with fruit
• Canned fish such as tuna or salmon (20 to 25g per serving): on crackers or in a small salad
• Betty Protein bars with a clean ingredient list and 14 to 16g per bar: for the moments when eating feels like a task
• Tofu, firm (17g per 100g): works well in small stir-fries or as a snack with soy sauce
• Edamame (17g per cup): one of the easiest plant-based snacks
Aim for 20 to 30g of protein at each main meal, even if those meals are much smaller than they used to be. Spreading protein across the day is especially important on GLP-1 medications because your body can only effectively use a certain amount at one time. Three small, protein-anchored meals will always outperform one large one.
Pair Protein With Resistance Training
If you are able to, combining adequate protein intake with some form of resistance training (even light weights or bodyweight exercise) is the most effective way to preserve lean muscle mass during GLP-1-assisted weight loss. The two work together: protein provides the raw material, and resistance training signals the body to use it for muscle maintenance and repair rather than simply burning it for energy.
You do not need to become a gym regular overnight. Even two to three sessions per week of light resistance work, like pilates or weight training makes a measurable difference to muscle preservation outcomes.
A Final Note
GLP-1 medications can be a useful tool for the right person, and consulting with your Doctor is reccommended. This is not about complicating that or making you second-guess your decision. It is about making sure you are getting the full benefit of what these medications can do, and protecting the things that matter long term: your muscle, your metabolism, your bone density, and your energy.
Protein is not an optional extra on this journey. It is the most important nutritional variable you have control over.
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References: European Congress on Obesity 2025; Haines M. et al., ENDO 2025 (Endocrine Society); Prado C.M. et al., The Lancet Diabetes and Endocrinology (2024); Mozaffarian D. et al., American Journal of Lifestyle Medicine (2025).
