GLP-1 medications like semaglutide have changed how millions of people eat, by sharply reducing appetite. When you are eating less, what you eat matters more than ever: every bite needs to deliver protein, fibre and nutrients. This guide covers the food principles that help, whatever the reason you are eating smaller portions.
Why protein comes first
The single most important principle: protein preserves muscle. When you lose weight quickly on reduced appetite, some of that loss can come from muscle unless you get enough protein. Prioritising it at every meal protects lean tissue, keeps you stronger, and supports metabolism.
Because portions are smaller, choose protein-dense foods so a little goes a long way:
| Food | Protein (per 100g) |
|---|---|
| Chicken breast | ~31g |
| Skyr / Greek yogurt | ~11g / ~10g |
| Eggs | ~13g |
| Lentils (cooked) | ~9g |
| Tofu | ~8g |
Not sure how much you need? Our protein calculator gives a personalised target, and our high-protein foods list ranks the best sources.
Why fibre comes a close second
Fibre does two key jobs here: it supports fullness (helping small meals satisfy) and aids digestion (important, since constipation is a common GLP-1 side effect). This is where the “fibermaxxing” idea and GLP-1 eating overlap.
Increase fibre gradually and drink plenty of water. Going from low to very high fibre overnight can cause bloating. Build up slowly with vegetables, beans, lentils, wholegrains, nuts and seeds.
See our high-fibre foods list for the best sources, and our gut health foods guide, since fibre and gut health go hand in hand.
Make every bite count
With a smaller appetite, “empty” calories are a wasted opportunity. Aim for nutrient-dense foods that bring vitamins and minerals alongside protein and fibre:
- Proteins: eggs, fish, chicken, turkey, Greek yogurt, skyr, tofu, beans
- Fibre and colour: vegetables, berries, wholegrains, lentils
- Healthy fats (in moderation): olive oil, avocado, nuts, seeds
What many people find easier to limit
These are not strict rules, but foods that GLP-1 users often report tolerating less well:
- Greasy and fried foods (can trigger nausea)
- Very large portions (uncomfortable on a reduced appetite)
- Sugary drinks and ultra-processed snacks (low in the protein and fibre that matter)
The goal is not restriction for its own sake, but making your limited appetite work for you.
Protein and your muscle: the numbers that matter
There is a specific reason protein comes first on a GLP-1, beyond fullness: protecting muscle. Rapid weight loss on reduced appetite can cost muscle as well as fat, and muscle is what keeps your metabolism up and helps regulate appetite, both of which matter enormously for keeping weight off later.
Current guidance suggests around 1.2 to 1.6 g of protein per kg of body weight per day during active weight loss, well above the old general target. With a small appetite that takes planning: lead every meal with a protein source, use protein smoothies or Greek yogurt and skyr as easy tops-ups, and spread protein through the day rather than loading one meal. Use our protein calculator to set your personal target, and pair it with some resistance exercise to hold on to the muscle you have.
Managing side effects, and life after the medication
Two practical realities deserve their own guides. First, the most common early hurdles are nausea and constipation, both of which respond well to simple food changes; see foods that help with GLP-1 side effects. Second, since weight often returns once the medication stops, the habits you build now are what protect your results; see life after GLP-1: how to keep the weight off. Together with this guide, these cover the three stages: eating well, handling side effects, and maintaining the outcome.
The bottom line
Eating well on a GLP-1 medication comes down to a simple shift: since you are eating less, make it count. Protein first, fibre close behind, nutrient-dense whole foods throughout. These same principles help anyone eating smaller portions. Start with our protein calculator to set a target, then build meals around the high-protein and high-fibre foods that keep you full. For a ready-made template, try our GLP-1 meal plan.
This article is for general information only and is not medical advice. GLP-1 medications should be taken under medical supervision. Always follow the guidance of your doctor or a registered dietitian regarding your diet and medication.