If you've been prescribed a GLP-1 medication, food still matters, arguably more than before. With a smaller appetite, every meal needs to earn its place: enough protein to protect your muscles, enough fibre and fluids to support digestion, and enough nutrients to keep you feeling well while your body adjusts. This guide covers the practical, whole-food side of eating on a GLP-1 medication. It isn't medical advice, and it doesn't replace the guidance of your prescribing doctor or care team.
Always speak to your GP, pharmacist or an Accredited Practising Dietitian about what's right for you.
Why nutrition matters more on GLP-1
GLP-1 medications work by mimicking a natural gut hormone that helps regulate appetite and blood sugar. The result is a noticeably smaller appetite and that's the point. But when you eat less overall, the quality of what you eat matters a great deal.
Research suggests that between 20 and 40 per cent of the weight lost during GLP-1 therapy can come from lean mass, that's muscle, not just fat. A 2025 joint advisory from four leading nutrition and obesity organisations — the American College of Lifestyle Medicine, the American Society for Nutrition, the Obesity Medicine Association and The Obesity Society — puts it plainly: nutritional quality during GLP-1 therapy is a clinical priority, not an afterthought.
The three priorities: protein, fibre, fluids
1. Protein to protect your muscles
Protein is the single most important nutrient to prioritise. The joint advisory recommends 1.2–1.6 g of protein per kilogram of body weight daily, spread across meals, roughly 30–40 g per eating occasion (Mozaffarian et al., 2025). For a 75 kg person, that's around 90–120 g a day.
Practical ways to get there:
- Start the day with protein. Eggs, Greek yoghurt, a smoothie with a good protein powder, or overnight oats with nuts and seeds.
- Include protein at every meal and snack. Fish, chicken, legumes, tofu, cottage cheese, tinned tuna, whatever you enjoy.
- Keep it simple on low-appetite days. A protein smoothie, a small bowl of yoghurt with berries, or even a glass of protein water can bridge the gap when a full meal feels like too much.
If you'd like a hand working out your personal target, the protein calculator on our GLP-1 support page is a good starting point but your dietitian can tailor it to you.
Fibre to support your digestion
Constipation is one of the most common side effects of GLP-1 medications, and adequate fibre helps. The Australian recommendation is 25–30 g a day, though many people fall well short of that.
Good whole-food sources include:
- Vegetables: especially broccoli, peas, artichokes, sweet potato
- Legumes: lentils, chickpeas, beans
- Wholegrains: oats, quinoa, brown rice
- Fruit: berries, pears, apples (with the skin)
- Nuts and seeds like almonds, chia seeds, flaxseeds
One important note: build up fibre gradually, especially during dose escalation when your gut is still adjusting. Too much too fast can make bloating worse, not better. Pair increased fibre with plenty of water.
Fluids, more than you think
When you eat less, you also take in less water from food, so you need to drink more deliberately. Aim for at least 8–10 glasses of water or sugar-free fluids a day. Adequate hydration supports digestion, helps fibre do its job, and can ease nausea, one of the most commonly reported early side effects.
What a day of eating well looks like
You don't need a strict meal plan. Think of it as building every meal around protein first, then colour and fibre, then a little healthy fat. Here's a simple example:
Breakfast:
Greek yoghurt with berries, chia seeds and a drizzle of honey
You get: ~25 g protein, fibre from berries and seeds
Mid-morning:
A small protein smoothie (protein powder, banana, spinach, almond milk)
You get: Easy to manage on low-appetite days
Lunch
Grilled fish with roast vegetables, quinoa and a squeeze of lemon
You get: Protein + fibre + healthy fats
Afternoon
A few crackers with cottage cheese and cucumber
You get: Light protein, easy to digest
Dinner
Chicken and vegetable soup with lentils and wholegrain bread
You get: Warm, gentle, nutrient-dense
For more ideas, download our GLP-1 friendly recipes eBook at the bottom of the page.
Managing common side effects though food
Most side effects like nausea, bloating, constipation, GLP-1 fatigue and reflux are worst during the first few weeks and around dose increases. A few food strategies can help:
Nausea
Small, frequent meals; cold or room-temperature foods; ginger tea. Limit large portions, rich or greasy food, strong smells.
Constipation
Fibre-rich foods (build up gradually), plenty of water, movement. Limit low-fibre processed foods.
Bloating
Eat slowly, chew well, smaller meals more often. Limit carbonated drinks, eating too fast.
Reflux
Upright after eating, smaller meals, avoid lying down within 2 hours. Limit spicy, acidic or very fatty foods.
"Protein, fibre and hydration is the name of the game," says dietitian Shannon Christen. "It's got to be really intentional and nutritious" (UCHealth, 2025).
Foods to go easy on
GLP-1 medications slow gastric emptying, food sits in your stomach longer. That means certain foods are more likely to trigger discomfort:
- Fried and greasy foods is harder to digest when gastric emptying is already slower
- Sugary drinks and ultra-processed snacks low in nutrients, high in empty energy
- Alcohol is especially during the adjustment period; it can worsen nausea and interacts with blood sugar regulation
- Very spicy or acidic foods may trigger reflux or stomach discomfort
Don't forget movement
The joint advisory recommends resistance training two to three times a week, targeting the major muscle groups alongside regular walking or other activity you enjoy. Exercise isn't just about calories; when you're eating less, it's one of the best ways to protect muscle and bone.
Even 20 minutes of bodyweight exercises, a resistance band session or a brisk walk makes a real difference. The key is consistency, not intensity.
Micronutrients to watch
When your total food intake drops significantly, so does your intake of vitamins and minerals. The joint advisory flags several nutrients to keep an eye on: vitamin B12, vitamin D, iron, calcium, magnesium and thiamine. A varied, whole-food diet covers most of these but your doctor or dietitian may recommend a blood test and a daily multivitamin as a safety net.
Whole-food staples that make it easier
When your appetite is smaller and every meal counts, a few quality staples can help you hit your protein and fibre targets without overthinking it. These are the ones Teresa reaches for:
Protein made easy:
- Organic Pea Protein a clean, plant-based protein to build into smoothies, oats or baking. Great on low-appetite days when a full meal feels like too much.
- Whey Protein Isolate a pure, high-protein isolate to top up protein at breakfast or in a shake.
-
Protein Water a light, refreshing way to get protein and stay hydrated when you're active or a full meal isn't appealing.
Gut and digestion support:
- Probiotic + Prebiotic: probiotics plus prebiotic fibre to support gut health and regularity, helpful when constipation is a concern.
- Everyday Greens is an easy way to add greens when fresh vegetables are hard to manage.
-
Gut Collagen is protein plus gut-supporting ingredients in one scoop.
A GLP-1 medication is a tool and like any tool, it works best alongside the right habits. Eating well doesn't mean eating perfectly. It means building meals around protein, fibre and whole foods, staying hydrated, moving your body, and being kind to yourself on the days it's harder.
For a full list of the foods that support your body's own GLP-1, see our foods guide. And for the bigger picture what GLP-1 is, how food fits in, and recipes to get started visit our GLP-1 support hub.
This is general information only. Always speak to your GP, pharmacist or an Accredited Practising Dietitian about what's right for you.
FAQ
What should I eat for breakfast on a GLP-1 medication?
Start with protein: eggs, Greek yoghurt, a protein smoothie or overnight oats with nuts. Pair it with fibre from fruit or seeds to keep you satisfied through the morning.
How much protein do I need on a GLP-1 medication?
Current guidance recommends 1.2–1.6 g per kilogram of body weight daily, spread across meals. For most adults, that's roughly 80–120 g a day — your dietitian can help you find the right target.
Why do GLP-1 medications cause constipation?
GLP-1 medications slow gastric emptying, which can slow the whole digestive tract. Eating enough fibre, drinking plenty of water and staying active all help keep things moving.
Can I drink alcohol on a GLP-1 medication?
It's best to go easy, especially early on. Alcohol can worsen nausea and may affect blood sugar control. If you do drink, keep it light and have it with food. Ask your prescriber for personalised advice.
Do I need to take vitamins on a GLP-1 medication?
When you're eating significantly less, your intake of certain vitamins and minerals can drop. A varied whole-food diet helps, but your doctor may recommend a blood test and a daily multivitamin as a precaution.
Sources
1. Mozaffarian D, et al. Nutritional priorities to support GLP-1 therapy for obesity: A joint Advisory. AJCN / Obesity, 2025. Read the advisory
2. Stuk S. Nutrition for maintaining muscle while taking GLP-1 RAs. HealthEd Australia, 2025. Read the article
3. UCHealth. Warning: Nutrition is vital when taking GLP-1 weight loss drugs. 2025. Read the article
4. Cleveland Clinic. GLP-1 Diet: What to Eat and Avoid. Read the guide
5. Dietitians Australia. Fibre. dietitiansaustralia.org.au
6. NHMRC. Australian Dietary Guidelines. National Health and Medical Research Council, 2013. eatforhealth.gov.au
