Guide
Diarrhoea on Wegovy: what to eat (and still hit your protein)
Diarrhoea (diarrhea, in US spelling) is one of the common gut side effects on Wegovy, most often in the first weeks and after a dose step, and for most people it settles within days. The food answer is the opposite of the constipation one: less fat, less raw fibre and no sugar alcohols for a few days, with plain protein that is easy on the gut, and fluid with salt in it rather than water alone. Protein stays at the floor even on a bad day, because a week of dry toast is a week the muscle pays for. Diarrhoea that lasts more than a few days, that comes with fever, blood, severe pain or signs of dehydration, belongs with your prescriber, and same day if you cannot keep fluid down.
Your number, before anything else
Protein is what decides whether the weight you lose is fat or muscle. Work your number out once and we will keep it with you on every page here. No account, no email.
Saved in this browser only. Your dose and how you feel on Wegovy stay between you and your prescriber.
At the higher Wegovy doses the gut can be unsettled for longer after each step. If the pattern is the same every week, keep the gentle day plan for the post-injection days as a standing arrangement rather than reacting each time.
A gentle day at about 100 g of protein
- Breakfast: 2 poached eggs on white toast with a banana, about 13 g
- Lunch: 120 g (4 oz) poached chicken with white rice and cooked carrot, plus a cup of salted broth, about 37 g
- Afternoon: a whey isolate or lactose-free shake in 250 ml (8.5 fl oz) of water or lactose-free milk, about 25 to 30 g
- Dinner: 120 g (4 oz) baked white fish with mashed potato, about 25 g
Around 100 g of protein, low in fat and raw fibre, with salt and fluid built in. Two or three days on this pattern settles most cases we see. If it does not, or if you cannot keep fluid down, that is a prescriber conversation rather than a food one.
Work out your own target on WegovyWhy a slowed stomach can still produce loose stools
Semaglutide mimics the gut hormone GLP-1: it slows stomach emptying, tells the brain you are full sooner, and steadies blood sugar after meals. Slowing the stomach does not slow everything below it, and the change in what and how much you eat matters as much as the medication. Fat that used to be digested comfortably now arrives in the gut in a different rhythm, sugar-free sweets and protein bars built on sugar alcohols pull water into the bowel, and a diet that has suddenly become mostly shakes, fruit and salad is very different from what the gut was used to. In STEP 1, which tested the top semaglutide step, nausea was the most common side effect (roughly four in ten people) and about one in four reported constipation, mostly around dose steps. Diarrhoea sits in the same group of side effects and tends to cluster around dose steps in the same way.
The cost is protein and fluid, in that order. Pooled across 20 randomised trials, 35.2% of the weight lost on semaglutide was lean mass, against 26.2% when the same weight came off by diet alone, and 17.5% when resistance training was added. The days when the gut is unsettled are the days the people we coach eat toast, drink tea and skip the chicken, and a bad week can put the seven-day protein average under the floor without anyone noticing. Loose stools also take fluid and sodium with them, which is why the tiredness, the cramps and the light-headedness often arrive together.
Settling it inside a week
Cut the fat and the sugar alcohols first
Fried food, fatty meat, cream sauces and cheese-heavy meals go for a few days. Then read the labels on protein bars, sugar-free sweets and some shakes: anything ending in -itol, such as sorbitol, maltitol or xylitol, is the usual hidden cause.
Choose the gentle proteins
Poached chicken, white fish, eggs, tofu, Greek yoghurt if dairy sits well, and a whey isolate or a lactose-free shake if it does not. Plain, warm, small, and 25 to 30 g each time.
Replace the fluid with salt in it
Water alone is not enough when you are losing fluid. A cup of salted broth, an oral rehydration sachet, or milk if you tolerate it, alongside 2 litres (68 fl oz) of plain fluid across the day.
Bring the fibre back slowly, cooked before raw
Oats, white rice, banana, cooked carrot and potato for a few days, then the beans, bran and salads come back one at a time once things settle. Raw vegetables and a big salad are the last thing back, not the first.
Make the gentle day a standing plan around each dose step
Wegovy steps up every four weeks or so, and the gut often reacts each time. Have the poached chicken, rice and broth in the fridge before the step rather than after.
How you will know it is working
A week of loose stools shows up on the scale as a flattering drop that is mostly water. These three numbers ignore the water and report the muscle.
One strength test, same way every week
Goblet squat reps at a fixed weight, push-ups, or the 30-second sit-to-stand for beginners. Fat loss does not make you weaker, so a number that drops three or four weeks running is a real signal, and it is fixable. It measures what you can do, not how much muscle you have.
Average protein a day, whole week
Not your best day. 1.2 to 1.6 g per kg of goal body weight (0.55 to 0.7 g per lb), floor 1.2, protein first at every meal.
Upper arm tape, same spot, relaxed
Centimetres or inches. The waist shrinks whatever you do; if the arm shrinks as fast, that is muscle. Weight is number four, same day and time. The scale tells you what you lost. These tell you what you kept.
See your prescriber about diarrhoea that
- Lasts more than three or four days, keeps returning after every dose, or comes with vomiting that stops you keeping fluid down, which is a same-day call
- Comes with blood or black stools, fever, severe or persistent abdominal pain, or pain in the upper right abdomen after fatty food
- Arrives with signs of dehydration: very dark urine, dizziness on standing, a racing heart or confusion, particularly if you take blood pressure tablets, diuretics or diabetes medication
Dose and timing on Wegovy are your prescriber's decisions; we coach the food and the strength.
Questions people ask
Does Wegovy cause diarrhoea?
Loose stools are among the common gut side effects reported with these medications, usually in the first weeks and around dose steps, and for most people they settle within days. What you eat makes a large difference, particularly fat, sugar alcohols and sudden changes in fibre.
What should I eat when I have diarrhoea on Wegovy?
Plain, low-fat protein such as poached chicken, white fish, eggs, tofu or a whey isolate, with white rice, oats, banana and cooked vegetables. Salted broth or a rehydration sachet alongside water. Cut fried food, sugar-free products and raw salad for a few days.
Why do I get diarrhoea after my Wegovy injection?
Gut side effects cluster in the days after each injection, when blood levels peak, and after each dose step. A low-fat, low-raw-fibre plan on those days with salted fluid usually settles it. Persistent symptoms belong with your prescriber.
What the evidence actually says
Losing fluid and eating less at the same time is where deficiencies start, so this page carries the floor and the markers.
Guideline-informed protein targets during this kind of weight loss start at 1.2 g per kg of body weight a day (0.55 g per lb). Arslan S, Clinical Nutrition ESPEN 2026
Vitamin D, B12, iron studies, folate, zinc and thiamine are the markers this literature suggests watching. Ask your prescriber whether they are worth checking for you; we do not order or interpret bloods. Arslan S, Clinical Nutrition ESPEN 2026
The papers these numbers come from
- Arslan S. Medical nutrition in the glucagon-like peptide-1 (GLP-1) era: Protein strategies, micronutrient monitoring, and lean mass preservation. Clinical Nutrition ESPEN, 2026. Narrative review, guideline-informed targets. doi:10.1016/j.clnesp.2026.103305
- Eisa N, Barood O. Lean Mass Changes With Incretin Therapy Versus Lifestyle Intervention: A Systematic Review and Meta-Analysis of Randomised Controlled Trials. Diabetes, Obesity and Metabolism, 2026. 20 randomised controlled trials, 15,782 participants. doi:10.1111/dom.70666
Last reviewed 18 September 2026. We update these figures when a larger or better study replaces them, and we say what changed. How we handle evidence.
The Keep Muscle Kit
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EverStrong provides nutrition and strength coaching and education. It is not medical advice and does not replace your prescribing doctor. Consult your doctor before starting a new exercise or nutrition plan, especially with a heart, kidney, liver or metabolic condition, if pregnant, or with a history of disordered eating.