What should I eat on a GLP-1 like Ozempic or Mounjaro?

Protein first at every meal, small meals more often, less fat per sitting, and fibre and fluid on purpose rather than by accident. The drug handles the calorie restriction; your job is making sure the little you eat carries enough protein, fibre and fluid.

What changes should I expect in my appetite and digestion?

Appetite drops sharply, you feel full after a few bites, and gastrointestinal effects are common early on: nausea above all, plus constipation, diarrhoea, reflux and burping. They cluster around starting the drug and each dose increase, and mostly settle over the following weeks.

How do I avoid losing muscle on a GLP-1?

Eat roughly 1.2 to 1.6 g of protein per kg of body weight a day and lift weights two to three times a week. Body-composition substudies put lean tissue at roughly a quarter to two-fifths of the weight lost, which is what large fast weight loss does generally rather than something these drugs do uniquely.

Does the advice change depending on which GLP-1 I take?

The principles do not. What differs is the rhythm (a weekly injection concentrates side effects into the days after the dose), the size of the weight loss, and one practical exception: oral semaglutide must be taken on an empty stomach with nothing to eat or drink for at least 30 minutes afterwards.

Is this medical advice?

No. It is food guidance for people already prescribed these medicines. Nothing here covers doses, escalation or where to obtain anything, and symptoms like persistent vomiting or severe stomach pain are for your prescriber the same day, not for a diet change.

Eating on GLP-1 Medication

These drugs solve the intake problem and create a nutrition one: a fraction of the appetite, a stomach that empties slowly, and every mouthful having to earn its place. This section covers what to eat, what your appetite and digestion will actually do, how to keep muscle while the weight comes off, and how the individual medicines differ.

Read this first: food advice, not medical advice

These are prescription medicines. Everything here is about what and how to eat while you are on one; nothing here is dosing, titration or prescribing guidance, and none of it replaces your prescriber, GP or dietitian.
Persistent vomiting, an inability to keep fluids down, or severe stomach pain that spreads to your back and does not go away are reasons to seek medical help the same day, not to adjust your diet and hope.
If you also take insulin or a sulfonylurea, eating much less can drop your blood sugar too low. Your prescriber needs to know before you cut your intake.
Buying these compounds outside a pharmacy, including anything sold as a research peptide, means no guarantee of purity, dose accuracy or sterility, and no clinician watching what happens next.
If you are pregnant, trying to conceive or breastfeeding, or have a history of pancreatitis, gallbladder disease or an eating disorder, talk to your clinician before changing how you eat on these drugs.

The guides

What to Eat on GLP-1 Medication
Protein first, small and often, fibre and fluid on purpose: what to put on a plate you may not finish.
Appetite and Digestion Changes to Expect on a GLP-1
Every change people report, when it typically arrives, why it happens, and the food-side response to each.
Protein and Muscle on GLP-1 Medication
What the trials found about lean mass, and the two things that protect it: enough protein, and lifting.
Foods That Make GLP-1 Side Effects Worse
What to pull back on, in order of how much difference it makes, and what to eat instead.
GLP-1 Medications Compared: What Each One Means for Eating
Every drug people ask about, with its status stated plainly and its practical eating implications.

The medicines at a glance

Status is as at the review date below and changes frequently. The comparison guide gives each one a section: what the trials found, how appetite and digestion behave on it, and what it changes about how you eat.

Medicine	What it acts on	How it is taken	Status
SemaglutideWegovy, Ozempic, Rybelsus	GLP-1 receptor agonist	Weekly injection, or a daily tablet	Licensed in the UK
TirzepatideMounjaro, Zepbound	Dual GIP and GLP-1 receptor agonist	Weekly injection	Licensed in the UK
LiraglutideSaxenda, Victoza	GLP-1 receptor agonist	Daily injection	Licensed in the UK
DulaglutideTrulicity	GLP-1 receptor agonist	Weekly injection	Licensed in the UK
ExenatideByetta, Bydureon	GLP-1 receptor agonist (the original one)	Twice-daily or weekly injection	Discontinued in the UK
OrforglipronFoundayo	Non-peptide GLP-1 receptor agonist (a small molecule, not an injectable peptide)	Daily tablet	Licensed elsewhere, not yet routine in the UK
Cagrilintide with semaglutide (CagriSema)	Amylin analogue combined with a GLP-1 receptor agonist	Weekly injection	Not approved anywhere
Retatrutide	Triple GIP, GLP-1 and glucagon receptor agonist	Weekly injection	Not approved anywhere

Frequently asked questions

What should I eat on a GLP-1 like Ozempic or Mounjaro?: Protein first at every meal, small meals more often, less fat per sitting, and fibre and fluid on purpose rather than by accident. The drug handles the calorie restriction; your job is making sure the little you eat carries enough protein, fibre and fluid.
What changes should I expect in my appetite and digestion?: Appetite drops sharply, you feel full after a few bites, and gastrointestinal effects are common early on: nausea above all, plus constipation, diarrhoea, reflux and burping. They cluster around starting the drug and each dose increase, and mostly settle over the following weeks.
How do I avoid losing muscle on a GLP-1?: Eat roughly 1.2 to 1.6 g of protein per kg of body weight a day and lift weights two to three times a week. Body-composition substudies put lean tissue at roughly a quarter to two-fifths of the weight lost, which is what large fast weight loss does generally rather than something these drugs do uniquely.
Does the advice change depending on which GLP-1 I take?: The principles do not. What differs is the rhythm (a weekly injection concentrates side effects into the days after the dose), the size of the weight loss, and one practical exception: oral semaglutide must be taken on an empty stomach with nothing to eat or drink for at least 30 minutes afterwards.
Is this medical advice?: No. It is food guidance for people already prescribed these medicines. Nothing here covers doses, escalation or where to obtain anything, and symptoms like persistent vomiting or severe stomach pain are for your prescriber the same day, not for a diet change.

Elsewhere on the site

Written and reviewed by Mathew Beale, MSc Biotechnology, University of Reading.

Last reviewed: 29 July 2026