What to eat on weight-loss drugs – a nutritionist’s high-protein daily plan

Most of us know someone who is taking GLP-1 injectables – perhaps better known by the brand names Wegovy, Ozempic and Mounjaro – which work by making people feel fuller. This results in them eating less – leading to quick and often quite dramatic weight loss.

But GLP-1s don’t just target body fat – they reduce overall weight, which means some lean mass and muscle are usually lost too. In fact, research suggests that, on GLP-1 medications, roughly a quarter of the weight lost is lean mass, including muscle and bone.

Of course, some muscle loss is expected with any form of weight loss. What’s less clear is whether people taking GLP-1s lose more muscle than they should – or whether that loss could have longer-term consequences for strength and metabolism.

That’s why what you eat on GLP-1s really matters.

When your appetite is suppressed, every bite needs to work harder to make sure your food is packed with as many nutrients as possible.

According to Mark Gilbert, nutritionist at PortionIQ, the answer is prioritising nutrient-dense, high-protein meals that support muscle mass, metabolic health and micronutrient intake.

‘Most people in Europe and North America, in all age and gender categories, are deficient in at least one essential nutrient,’ he says.

‘So, when someone goes on weight-loss drugs and substantially reduces their food intake, the likelihood of deficiencies becomes even greater, unless they change their diet to include more nutrient-dense foods.’

Gilbert recommends focusing on nutrient density and protein intake above all else. ‘The most informed nutrition experts these days agree that the minimum protein requirement (0.8g of protein intake per kilogram of body weight) is not adequate, even for people eating a typical amount of calories,’ he says.

‘When restricting calories, your protein intake should be even higher. This is because the risk of losing lean body weight (muscle, bone, organs, etc.) increases when losing weight. As such, I would recommend people on GLP-1s get a minimum of 1.5g of protein per kilogram of their body weight per day.’

So what does this look like in practice? Here, Gilbert offers an example of what a typical day of eating on GLP-1s should look like when you're prioritising protein...

Breakfast

High-protein Greek yoghurt (300g), mixed berries (1 cup)

Greek yoghurt contains high-quality, complete protein that is rich in essential amino acids. ‘This will help to preserve lean muscle mass when calories are low and appetite is suppressed,’ says Gilbert.

‘Mixed berries are high in fibre, vitamin C and polyphenols. They support gut health and digestion, which can slow on GLP-1s, and help maintain micronutrient intake despite lower calories.’

Lunch

Salmon (200g), mixed leaf salad with cherry tomatoes, cucumber, balsamic vinegar and a splash of extra virgin olive oil dressing

‘Salmon is rich in protein and omega-3 fatty acids (EPA and DHA). Protein protects muscle mass, while omega-3s support metabolic health and reduce inflammation, which can improve overall outcomes during weight loss.

‘Mixed leaf salad, cherry tomatoes and cucumber are high in fibre, vitamins and minerals with very low calories. This helps prevent micronutrient deficiencies, which are more likely when eating less on GLP-1s. These ingredients are also quick and easy to prepare.

‘Olive oil is a source of healthy fats that aid nutrient absorption. Fat improves absorption of fat-soluble vitamins (A, D, E, K), critical when total food intake is reduced.’

Dinner

Sirloin steak (200g), roasted mixed Mediterranean vegetables with garlic and a splash of olive oil

‘Sirloin steak contains high-quality protein plus iron, zinc and B vitamins, which support muscle retention, energy levels and prevent deficiencies such as iron deficiency, which can worsen fatigue during calorie restriction,’ says Gilbert.

‘Roasted vegetables contain fibre plus a wide spectrum of vitamins and antioxidants. This supports gut health and reduces the risk of deficiencies while also aiding digestion.

‘Olive oil and garlic contain healthy fats and bioactive compounds. They enhance flavour, making food more appealing when appetite is low, and contribute to overall nutrient density.’

Very Berry Bites by PortionIQ

‘Specifically formulated for people on GLP-1s, PortionIQ’s range of GLP-1-friendly snacks, including Very Berry Bites, contains high-quality protein and high levels of vitamins and minerals,’ explains Gilbert. ‘They are also low in calories and volume, matching the reduced appetite caused by GLP-1 medications.’

High-protein Greek yoghurt with cocoa and honey and/or berries

Greek yoghurt is a nutrient-dense, tasty and high-protein option, he says. ‘Maintaining protein intake across the day is key for muscle preservation.’

Tinned sardines

Sardines are high in the essential fatty acids EPA and DHA and high in protein, B vitamins, calcium, selenium and vitamin D, adds Gilbert. ‘This supports muscle retention and ensures adequate omega-3 intake without large portions, while addressing common micronutrient gaps that can worsen with reduced calorie intake, with no preparation required.’

This sample meal plan is designed to be nutrient-dense while keeping calories relatively low – coming in at around 1,000 calories below the average recommended daily intake, and likely lower than what many on GLP-1s consumed before starting medication.

It provides roughly 130g of protein, alongside fibre, essential fats, vitamins and minerals. But, as ever with nutrition, it’s not a one-size-fits-all approach.

Mark Gilbert recommends that this meal plan be adjusted based on your size, sex and activity level. He also says it’s best to consult your doctor if you feel your appetite is unduly restricted. For example, if you’re on GLP-1s and you cannot follow this diet plan as outlined above, Gilbert suggests discussing lowering your medication dosage with your doctor. ‘An overly restricted diet would leave you susceptible to nutrient deficiencies and losing too much lean body mass,’ he says.