Life on a GLP-1: eating, exercise and injections

What should I eat on a GLP-1?

Smaller meals with protein first. You will eat less, so each bite needs to count for protein, fibre and fluids.

A 2025 advisory from four US nutrition and obesity groups proposes 1.2–1.6 g of protein per kg of body weight a day during weight loss.¹ The everyday minimum for adults is 0.8 g per kg.¹

For a 90 kg (198 lb) person, that works out to 108–144 g a day.¹ But using your full body weight can overestimate what you need.¹ So the same advisory offers a simpler goal: 80–120 g a day.¹ It also warns against staying at 2 g per kg or more for long.¹ If you have kidney disease, ask your doctor before eating more protein.

Eating the protein part of your plate first helps you finish it before you feel full.¹ The advisory favours beans and lentils, dairy, fish, eggs and chicken. It suggests keeping red and processed meat low.¹

Protein in everyday foods

We worked out each serving from the UK's official food tables (McCance and Widdowson's, known as CoFID).² Australian products may differ a little, so check the nutrition panel on the pack. Each line says whether the food is weighed raw, cooked or from a can.

Source: McCance and Widdowson's Composition of Foods Integrated Dataset 2021, protein per 100 g, multiplied up to each serving and rounded to whole grams.²

A worked example: 100 g chicken, 150 g Greek-style yogurt and 200 g baked beans add up to about 43 g of protein.² That is just over half of the 80 g goal.

Smaller meals, fibre and fluids

• Small meals. Vomiting is more likely after a large meal.¹
• If you feel sick: try a small breakfast, then small meals every 3–4 hours.¹
• Fibre, slowly. Go easy on high-fibre food in the first few days. After that, add fibre gradually to prevent constipation.¹
• Fluids. Losing fluids through vomiting or diarrhoea can harm your kidneys.^1,7 The advisory says to drink enough fluids.¹ For alcohol, see Questions people ask.

How do I keep my muscle?

Do strength exercise at least 3 times a week, and eat enough protein. Walking alone protects less muscle than walking plus strength training.¹

Not all the weight you lose is fat. In one semaglutide trial, of every 10 kg (about 22 lb) lost, about 4 kg was "lean mass": muscle and other non-fat tissue. About 2 kg of that was muscle.¹

The 2025 advisory suggests strength training at least 3 times a week, plus at least 150 minutes of moderate activity, like brisk walking.¹ The plan should match your fitness level.¹

What about Christmas, Ramadan and other fasts?

Big meals make vomiting more likely, so take small plates and stop early.¹ Fasting needs a plan, especially if you take insulin or a sulfonylurea (a type of diabetes tablet, such as gliclazide).^8,13

Christmas, barbecues and big meals

Christmas lunch, summer barbecues, office parties, weddings, Eid and Diwali meals all follow the same rules:¹

• Small portions, eaten slowly, with the protein first.¹
• Fewer rich, fried and sweet dishes.¹
• Keep alcohol to a minimum.¹
• You don't have to finish what you're served, or have a second helping to be polite.

If your injection day lands on a big day and you'd rather move it, you can, as long as there are at least 3 days between two doses.^4,5 Christmas here falls in summer, so drink enough on hot days, and keep your pen out of hot cars and away from the beach bag: see storage.

Ramadan

The main international guidance is the 2021 Ramadan guidelines from the International Diabetes Federation and the Diabetes and Ramadan International Alliance (IDF-DAR).^11,12 Advice written for UK pharmacists in July 2026 builds on them:¹³ About 3 in 100 Australians are Muslim.²⁰

• GLP‑1 medicines can be used while fasting, if taken on schedule with a doctor's oversight.^11,12 Don't stop without medical advice.¹¹
• Finish dose increases first. That advice is to complete them at least 4 to 6 weeks before a planned fast, and to put off the next increase if the fast starts soon.¹³
• Weekly injections stay on the same day each week. Some people inject after iftar to limit nausea, others after suhoor to stay full through the day.¹³
• Watch for constipation and dehydration, especially when Ramadan falls in hot weather. Fasting raises the risk of these, and of missing nutrients. Fill the eating window with wholegrains, pulses, fruit, vegetables and enough fluids.¹³
• The research is mostly on older GLP‑1 medicines (liraglutide, lixisenatide and exenatide). The 2021 guidelines don't name semaglutide or tirzepatide, and say more research is needed.¹²

Other fasts

We found no Australian guidance written for GLP‑1 users during other religious fasts, such as Yom Kippur, Lent, Navratri or Karva Chauth. The same pharmacy advice applies to any planned fast: finish dose increases weeks before, and plan your fluids.¹³

How do I inject, and what if I miss a dose?

Inject once a week, on the same day, into your belly, thigh or upper arm. Use a new needle and a new spot each time.

• Where: just under the skin of the belly, thigh or upper arm.^3,5 For Mounjaro, the back of the upper arm is for someone else to inject.⁵
• When: any time of day, with or without food.^3,5
• Rotate: use a different spot each week.⁵
• Needles: a new needle every time. Don't store the pen with a needle on.⁸
• Never share a pen, even with a new needle. It can spread serious infection.⁸

Getting rid of needles and pens

• Use a sharps container, or a strong puncture-proof container with a lid, and put used needles straight in.¹⁷
• When it's full, ask your pharmacy, GP or local council where to drop it off. Arrangements vary between states and councils.
• Don't put loose needles in household or recycling bins. In New South Wales, the needle clean-up hotline is 1800 633 353.¹⁷
• Pen needles. The National Diabetes Services Scheme gives free pen needles to registered people who use insulin; we couldn't confirm whether that covers people on a GLP‑1 alone.¹⁸

Missed a dose?

Never take two doses to catch up. The Australian product information says to skip a late dose and carry on as normal on your usual day.^3,5 If you've missed more than one dose, ask your doctor before restarting. The Wegovy label says a lower restarting dose should be considered.³

On tablets?

• Rybelsus (for type 2 diabetes) is taken on an empty stomach, followed by a 30-minute wait.⁹ We found no GLP‑1 tablet approved for weight in Australia as of October 2026.

How do I store it in the heat, and travel with it?

Keep unopened pens in the fridge. Once in use, most can sit outside the fridge for a few weeks, but only below 30 °C.

Store new pens at 2–8 °C, away from the cooling element. Never freeze them, and never use one that has frozen.^3,4,5 Keep the cap on to protect the pen from light.³

From the Australian product information. Always follow the Consumer Medicine Information leaflet in your own pack.

Travelling. Diabetes UK's advice for insulin, which also needs fridge storage, fits here. Carry it in hand luggage, because the hold gets very cold and bags get lost.¹⁰ A cool bag helps, but don't let the pen touch frozen ice packs.¹⁰ Some airlines ask for a doctor's letter, so carry your prescription.¹⁰

How do I know if it's working?

Expect regular reviews. Australian guidance sets weight-loss targets with you and changes the plan if they aren't reached.¹⁴

1. Week 0Start on a low dose. Write down your weight and waist.
2. Every 4 weeksThe dose usually steps up, if side effects allow. If stomach side effects are bad, the next step can wait.^3,5
3. At reviewsCheck against your target. The Australian algorithm suggests 10–15% weight loss for many people, and stepping up or changing the plan if it isn't reached.¹⁴ For teenagers on Wegovy: stop if BMI hasn't fallen 5% after 12 weeks on the full dose.³
4. After thatRegular reviews, for as long as you take it. The algorithm says weight-loss medicines will usually be needed long term.¹⁴

For a 90 kg (198 lb) person, 10% is 9 kg, about 20 lb. Falling short doesn't mean you failed; smaller losses still help, especially for preventing diabetes.¹⁴ Your doctor weighs up the benefits and risks of carrying on. Guide 3 covers the other options.

On the older daily medicine liraglutide (Saxenda, and its generic copies), the label is stricter: stop after 12 weeks on the full 3 mg dose if you haven't lost at least 5%.¹⁵ And none of these medicines replaces diet and exercise: they're approved as an add-on to a reduced-energy diet and more activity.^3,5

What should I keep track of?

Your weight, waist and side effects, and your sugar if you have diabetes. Bring the notes to each review.

• Weight and waist: write them down, so you can compare at your reviews. Guide 1 shows how to measure your waist.
• Blood sugar, if you have diabetes: check before you start and while you take it.⁷ Low sugar can show as dizziness, sweating, shaking, blurred vision, confusion or a fast heartbeat.⁷
• Doctor checks: your heart rate, because your resting pulse can rise on these medicines. Tell your doctor if your heart races while you are resting.⁷ Kidney tests if you've had bad vomiting or diarrhoea.⁷ If you have diabetes, report any change in your eyesight: a fast improvement in blood sugar can briefly worsen diabetic eye disease (retinopathy).⁷
• Side effects and meals: note what you ate before nausea. Patterns help.
• Report side effects to the TGA, or ask your doctor or pharmacist to. Anyone can report.¹⁶

What about food noise and family meals?

Many people find the constant thoughts about food go quiet. Some also lose the pleasure of eating, and that can feel strange at family meals.

Studies show less "food noise", less emotional eating and fewer binges on these medicines.¹ But some people miss the joy of food, or of cooking for others.¹ If food has always been how your family shows care, that change can be hard. Talking it through, or seeing a counsellor, can help.¹

Don't skip meals for hours because you aren't hungry. Getting very hungry can bring back cravings for sweets and refined carbs.¹

At home, it helps if the people you eat with know why your plate is smaller. A simple line works: "I'm on a medicine that fills me up fast. I'll have a little of everything."

Questions people ask