Weight loss medication reduces appetite, but what you eat still matters for results, nutrition, and managing side effects.
General principles
- Protein first: Aim for 1.2–1.6g per kg body weight daily. Protein preserves muscle mass during weight loss and helps with satiety.
- Smaller portions: Your medication reduces appetite. Listen to it — eat until satisfied, not full.
- Hydration: Drink at least 2 litres of water daily. GI side effects are worse when dehydrated.
- Avoid trigger foods: High-fat and greasy foods worsen nausea on GLP-1 medications. Rich, heavy meals are harder to tolerate.
Medication-specific tips
On Wegovy or Mounjaro
- Eat slowly — your stomach empties more slowly on GLP-1 medications
- Have smaller, more frequent meals instead of 3 large ones
- Prioritise lean protein, vegetables, and complex carbohydrates
- Avoid carbonated drinks (can worsen bloating)
On Xenical (orlistat)
- Keep dietary fat to under 30% of total calories
- Higher fat = worse GI side effects (the medication blocks fat absorption)
- Take a multivitamin at a different time of day (orlistat blocks fat-soluble vitamins)
On Duromine
- Eat regular meals even if appetite is very suppressed
- Avoid caffeine (adds to stimulant effects)
- Don't skip meals — this can lead to bingeing when the medication wears off
Sample day of eating on GLP-1 medication
Here's what a typical day might look like once your appetite has adjusted:
- Breakfast: Greek yoghurt with berries and a handful of nuts (protein + fibre)
- Lunch: Grilled chicken salad with avocado and olive oil dressing (protein + healthy fats)
- Afternoon snack: Apple with peanut butter or a protein shake (only if hungry)
- Dinner: Salmon with roasted vegetables and quinoa (protein + complex carbs)
Total: approximately 1,200–1,500 calories, with 80–100g of protein. This is typical for someone on a GLP-1 medication — their naturally reduced appetite leads to this range without forced restriction.
The protein priority
Of all dietary factors, protein intake is the most important during weight loss medication treatment. Adequate protein (1.2–1.6g per kg body weight) preserves muscle mass, maintains metabolic rate, improves satiety between meals, and supports immune function. If you only change one dietary habit, make it eating protein at every meal.
Foods that worsen side effects
During dose escalation, these foods commonly trigger or worsen nausea on GLP-1 medications: fried foods, very rich or creamy sauces, large portions of red meat, carbonated drinks, very spicy food, and alcohol. Keeping meals simple and light during the first few weeks at each new dose makes the adjustment easier.