What to eat on Mounjaro and other GLP-1 medications.
An Australian nutrition guide for people already using, or about to start, a medically prescribed GLP-1 medication. Protein, fibre, fluids, nausea, constipation, hair and muscle, and what to do when appetite drops faster than your nutrition does.
Important. Wellbeing George does not prescribe, supply, sell, advertise or facilitate access to Mounjaro, tirzepatide, Ozempic, Wegovy, Saxenda or any other prescription-only medicine, and nothing here recommends starting or stopping one. This page provides general nutrition education for people already working with their own qualified medical practitioner.
The short answer
Build every meal around protein first, then add gentle fibre, fluids and colour in whatever volume you can comfortably manage. Smaller structured meals usually work better than waiting for hunger that no longer arrives. Increase fibre slowly and pair it with fluids, because constipation is one of the most commonly reported problems. Add resistance training, because that is what protects muscle while weight is coming off.
The reason this matters is arithmetic. If you are eating half as much food, every mouthful has to carry roughly twice the nutrition to keep iron, B12, folate, zinc, magnesium, calcium, vitamin D, protein and essential fats where they were.
A note on the names. These medicines are not identical. Semaglutide, in Ozempic and Wegovy, is a GLP-1 receptor agonist. Tirzepatide, in Mounjaro, acts on both GIP and GLP-1 receptors. "GLP-1" is used loosely as a catch-all, including on this page, but the nutrition principles below apply because appetite and gastric emptying change in similar ways, not because the drugs are the same.
Researching peptides more broadly at the same time? What is legal in Australia, and how collagen and supplement peptides differ from injectable products, is covered separately in our guide to peptides in Australia.
Smaller meals have to work harder.
Appetite suppression does the calorie part on its own. What it does not do is protect the nutrients, and that gap is where most of the problems people report actually come from.
The aim is not to eat less. It is to eat well in less.
Protecting energy, digestion, strength and nutrient status is what makes the result something you can keep.
Food first, but targeted.
When intake is lower, testing can show which nutrient patterns actually deserve the attention.
Build the day around protein, fibre, fluids and tolerance.
A GLP-1 diet plan is not a low-calorie meal plan with smaller portions. It has to account for reduced appetite, slower gastric emptying, nausea risk, constipation risk, muscle protection and nutrient density all at once.
Georgie has been amazing to work with. After just a few consults I have a better understanding of the food I’m eating and what it’s doing for my body. I’ve been able to make some small changes with my eating habits and it’s left me feeling less fatigued and more energized. I’ve also noticed I have less headaches and clearer skin.
Four things a plan should protect, beyond the number on the scale.
These are the areas we would build around for someone eating noticeably less during medically supervised treatment.
Protein
Supports satiety, lean mass retention and recovery while body composition is changing.
Digestion
Plan around nausea, reflux, constipation, bloating, slower eating and smaller portions.
Nutrients
Iron, B12, folate, zinc, magnesium, calcium, vitamin D and essential fats as intake drops.
Afterwards
The meal structure, strength habits and food skills that outlast the weight-loss phase.
GLP-1 nutrition risk checker
Six questions on whether your current eating pattern is strong enough for the appetite you actually have right now.
Constipation, nausea, hair and muscle.
These are the four things people search for most once treatment is underway. All four have a nutrition layer, and none of them replace a conversation with your prescriber. If one particular side effect is the whole problem, our Mounjaro side-effects nutrition guide takes nausea, constipation, reflux, diarrhoea, headaches, fatigue and hair shedding one at a time.
Constipation
Commonly reported, and usually the sum of several things at once: less food volume, less fibre, less fluid and often less movement. Slower gastric emptying adds to it.
The nutrition response is to raise fibre gradually while raising fluids at the same time, use sources that hold water well such as oats, chia, psyllium, cooked vegetables and legumes, and keep daily movement going. Raising fibre without fluids reliably makes it worse.
Severe, persistent or painful constipation needs medical review, not a food change.Nausea
Often worse with large meals, high-fat or fried food, alcohol and eating quickly. It tends to be the reason intake collapses, which is what turns a side effect into a nutrition problem.
Most people manage better with smaller, plainer, cooler meals eaten slowly: Greek yoghurt, eggs, soups, smoothies, toast with a protein, lean meats, tofu, cooked vegetables. Getting protein in during the windows when you do feel able to eat matters more than hitting a perfect daily total.
Persistent vomiting or an inability to keep fluids down needs medical attention promptly.Hair changes
Hair shedding is reported during rapid weight loss generally, not only with these medications. The usual explanation is telogen effluvium, where a sharp drop in energy intake or a physiological stressor pushes hair follicles into a shedding phase, typically showing up two to three months later.
Nutritionally, the things worth reviewing are total energy intake, protein, iron and ferritin, zinc, and vitamin D. Nothing here treats hair loss, and no supplement should be started on guesswork, but low intake of these is a plausible and checkable contributor.
Patchy loss, scalp symptoms or hair loss that keeps progressing should be assessed by a doctor.Muscle
Any substantial weight loss includes some lean mass, and the faster the loss and the lower the protein, the larger that share tends to be. It matters because muscle carries strength, glucose handling and a good deal of daily energy expenditure.
Two things reduce it, and they work together rather than separately: keeping protein intake up across the day, and doing resistance training two to four times a week. Protein without training, or training without protein, does noticeably less than both.
Weakness, dizziness or a rapid drop in strength should be discussed with your practitioner.There is no banned-food list. There are foods worth watching.
People search for foods to avoid, but tolerance here is genuinely individual. The useful exercise is finding which foods worsen nausea, reflux, bloating or constipation for you, then replacing them with something you will actually eat rather than simply eating less.
If you are eating less and feeling flat, start with what is actually missing.
Wellbeing George supports the nutrition layer around your medical care: testing, interpretation, food-first planning, and a free 15-minute call if you are not sure where to begin.
Complete Nutritional Blueprint
For nutrient gaps, reduced appetite, fatigue and protein planning when intake has dropped.
Organic Acids Test (OAT)
Where fatigue, energy production or nutrient metabolism need a closer look.
DUTCH Complete
For people also navigating cortisol rhythm, perimenopause or menopause-related patterns.
Wellbeing George provides online nutrition support across Australia, including Victoria, New South Wales, Queensland, Western Australia, South Australia, Tasmania, the Australian Capital Territory and the Northern Territory. Managing a specific symptom right now? Start with the side-effects guide.
GLP-1 nutrition questions.
These answers are deliberately limited to nutrition. Suitability, side effects, access, dosage, pricing and availability are for your medical practitioner or pharmacist.
What should I eat on Mounjaro or another GLP-1 medication?
Put protein first at every meal, then add fibre-rich carbohydrates, vegetables, fluids and healthy fats in whatever amount you tolerate. Smaller structured meals or mini-meals usually work better than large meals when appetite is low, because the first few bites end up being most of what you eat.
What does a good GLP-1 diet plan look like?
It is built around protein, fibre, hydration, nutrient density, personal food tolerance and resistance training. It should not simply be a very low-calorie plan, because reduced appetite is already doing that part, and stacking a restrictive plan on top is how nutrient intake ends up too low.
How much protein do I need on a GLP-1 medication?
Protein needs vary with body size, training, health history and goals, so a single number is not useful. A practical starting point is a protein-rich food in every meal or mini-meal, eaten before the rest of the plate, then personalised from there with a practitioner.
Why is constipation so common on GLP-1 medications, and what helps?
It is usually several things at once: less food volume, less fibre, less fluid, less movement, and slower gastric emptying. The nutrition response is to raise fibre gradually while raising fluids alongside it, using sources like oats, chia, psyllium, cooked vegetables and legumes, and to keep daily movement going.
Severe, persistent or painful constipation needs medical review rather than a food change.
What can I eat when I feel nauseous on a GLP-1 medication?
Most people tolerate smaller, plainer, cooler meals better than large or rich ones. Greek yoghurt, eggs, soups, smoothies, toast with a protein, lean meats, tofu and cooked vegetables are common choices. Eating slowly helps as much as the food choice does. Persistent vomiting or being unable to keep fluids down needs prompt medical attention.
Are there foods to avoid on Mounjaro or a GLP-1 medication?
There is no universal banned-food list. Some people find very large meals, fried food, alcohol, carbonated drinks, spicy food, rich desserts or simply eating quickly harder to tolerate. Track what actually affects you and focus on replacements rather than removal, so total intake does not fall further.
Can weight loss on a GLP-1 medication cause muscle loss?
Any substantial weight-loss phase includes some lean mass, and the share tends to be larger when protein intake is low and there is no resistance training. Keeping protein up across the day and training with resistance two to four times a week are the two levers that reduce it, and they work together rather than separately.
Can GLP-1 medications be linked to hair loss?
Hair shedding is reported during rapid weight loss in general, not only with these medicines. It is usually described as telogen effluvium, where a sharp drop in energy intake or another physiological stressor pushes follicles into a shedding phase, often appearing two to three months afterwards.
Nutritionally the things worth reviewing are total energy intake, protein, iron and ferritin, zinc and vitamin D. Patchy loss, scalp symptoms or loss that keeps progressing should be assessed by a doctor.
What if my weight loss plateaus?
A plateau does not automatically mean eating less. Sleep, stress, constipation, protein intake, resistance training, alcohol, daily movement, under-fuelling and existing hormone or insulin patterns can all influence it. Anything to do with the medication itself belongs with your prescriber.
Can Wellbeing George advise on cost, access, dosage or pharmacy availability?
No. Wellbeing George does not provide prescription medicine access, pricing, dosage, pharmacy stock or suitability advice, and does not supply or advertise these medicines. Those questions belong with your prescribing doctor or pharmacist. Our role is limited to nutrition education, food planning, nutrient intake, testing options and practitioner-led nutrition support.
Can Wellbeing George help while I am on a GLP-1 medication?
Yes, from a nutrition perspective only. That covers meal structure, protein intake, nutrient density, constipation and nausea-aware food strategies, fatigue patterns, testing options and the food habits that need to hold once the weight-loss phase ends.
Lower appetite should not mean lower nutrition.
If you are using a GLP-1 medication under medical care and want to protect energy, digestion, muscle and nutrient status, start with a clear picture of what is actually low, or talk it through first.
Georgina and the team at Wellbeing George are amazing to deal with and very professional. I was unsure as to what to expect as the testing protocol seems quite new, but after the 15min free consult I was totally convinced that it was exactly what I needed to try.
Reviewed by Georgina Waugh
Clinical Nutritionist, BHSc Nutritional Medicine
Last reviewed: 3 September 2026
Scope: nutrition education only. Wellbeing George does not prescribe, supply or advise on any prescription medicine.
This page is for general educational purposes only and does not provide medical advice, prescribing advice or treatment recommendations. Wellbeing George does not advertise, supply or facilitate access to prescription medicines. Nutrition information here is intended for people already under the care of a qualified medical practitioner, and does not replace that care. For information about therapeutic goods in Australia, refer to the Therapeutic Goods Administration.