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Orlistat is a prescribed medicine which is used in conjunction with lifestyle changes to treat obesity when diet and exercise alone have not worked.
When is Orlistat used?
Orlistat is a prescribed medicine which is used in conjunction with lifestyle changes to treat obesity when diet and exercise alone have not worked.
It is used in patients who have:
- A BMI 30kg/m² or more OR
- A BMI 28kg/m² or more with associated risk factors.
Orlistat works in your intestine (gut) where it blocks some of the fat you have eaten from being absorbed. The undigested fat then passes out of your body with your faeces (stools).
This can lead to changes in your bowel habits e.g. loose, oily or fatty stools. You can decrease the chance of this happening by reducing the amount of fat in your diet. If you eat less fat, absorb less fat and exercise, you should lose weight.
If Orlistat is not helping you to lose weight after three months, it is unlikely to be an effective treatment for you. Your doctor or dietitian will recommend that the treatment is stopped.
How Should I take Orlistat?
Orlistat is usually taken three times a day at meal times. It should be taken up to an hour before, during, or up to an hour after your meal.
It only works when there is fat in the meal. So if you miss a meal or have a meal with no fat in it, you do not need to take a dose of Orlistat.
Please read the Patient Information Leaflet provided in the pack of Orlistat capsules. If you have any questions ask your Doctor or Community Pharmacist.
Side effects
It can take several days for your body to become used to this medication during which time you may experience some side effects.
- Headache
- Fatty or oily stools or discharge
- Passing stools more frequently
- Flatulence (wind)
- Abdominal pain.
Remember, if you eat too much fat in your diet while taking Orlistat, these side effects may continue.
Warnings
Women taking an oral contraceptive pill are advised to use an additional method of contraception, such as a condom, if they experience severe diarrhoea while taking Orlistat. This is because if you have diarrhoea, your contraceptive pill may not be absorbed by your body, and so may not be effective.
Orlistat should not be taken during pregnancy or breastfeeding.
If you are taking other medicines inform your doctor or pharmacist as these may interact with Orlistat.
Losing weight may mean that dosage adjustments are required for some medicines – discuss this with your doctor.
What dietary changes do I need to make?
Your food intake needs to follow the principles of a healthy balanced diet:
- Regular meals
- Low fat
- Eat a balance of the five food groups – fruit and vegetables, starchy foods, dairy, protein and fats
- Watch your portion sizes
- Orlistat may reduce the absorption of some fat-soluble vitamins (vitamins A, D, E and K). Discuss this with your dietitian.
Further dietary advice can be discussed with your dietitian.
Food labelling
Check the labels of products to check that they are low in fat. Choose products containing no more than 5g fat per 100g. If you would like more information on fat and labelling please speak with your dietitian.
|
|
High fat foods - To be avoided |
Low fat alternativeSometimes there isn’t a low fat alternative but we have tried to include some |
|
Starchy foods |
Pastry, croissants, pies, sausage rolls. Garlic bread, Creamy pasta/ rice sauces Fried rice / Fried chips Mashed potato Breakfast bars, Crunchy oat |
Toast or sandwich with low fat spread Wholemeal bread with Choose tomato based Oven chips/ potato wedges with spices Potatoes, no butter (try low fat fromage frais or Greek yoghurt instead) Bran, cornflakes, wheat based cereal with skimmed milk |
|
Fruit and vegetables |
Avocado* Butter on Cream, ice cream added to fruit
|
All other types fruit and Add low fat yoghurt to fruit Stir fry vegetables with 1 spray of oil
|
| “Cream of” soups e.g. tomato, mushroom, chicken |
Clear/broth based soups, e.g. minestrone, vegetable, leek and potato, carrot and coriander. | |
| Protein foods |
Fried meats, Pork crackling, pork scratching Fried eggs Nuts and seeds* |
Cut all visible fats from meat, drain fat off when cooking. Check labels, buy lean meat. Chicken with skin removed Fish (all types) ensure if tinned its in spring water/tomato sauce, not in oil. Beans, lentils and pulses Quorn and tofu |
| Dairy foods |
Full fat hard cheese, cream cheese Full fat/ creamy Yoghurt Whole milk, Evaporated milk Milkshakes |
Small amounts strong cheese, grated to use less. Low fat soft cheese, cottage cheese Virtually/fat-free yoghurt Semi-skimmed or skimmed milk, soya milk. Smoothies, made up with fruit and skimmed milk or low fat yoghurt |
| Fats and oils | Butter, lard, ghee | Small amounts of low fat spread, |
|
Mayonnaise, salad cream Olive oil*, Gravy Coconut milk/ Creamy based sauce e.g. |
1 tsp. reduced fat Use vegetable/olive oil spray Limit portions of gravy to one tblsp, skim fat off cooking juices or use gravy granules. Low fat or use in small amounts. Choose |
|
| Snacks |
Biscuits, cakes Crisps Breakfast bars Chocolate (dark, milk) |
Rich tea, arrowroot, jaffa cake, Soreen malt loaf Baked crisps, quavers, rice cakes, crackers |
| Puddings |
Cream, ice cream, Cake, desserts |
Low fat yoghurt, fruit salad, low fat custard, low fat rice pudding. |
| Drinks |
Cream Liquors, e.g. Baileys Coffee mate Hot chocolate, |
Spirits with diet mixer Skimmed milk Make with skimmed milk or water, choose light options - check the label. |
*These foods can be re-introduced in small amounts when your course of Orlistat has finished as they are ‘good fats and oils’.
Sample menu
Breakfast:
- Fruit or unsweetened fruit juice
- Wholegrain cereal with low fat milk.
Or
- Wholemeal toast with low fat spread.
Light meal:
- Wholemeal or granary bread/wholegrain crackers/baked potato
- Lean meat/fish/egg or low fat cheese
- Plenty of mixed salad/vegetables
- Fruit or low fat yoghurt.
Main meal:
- Lean meat/fish/pulses
- Potatoes/rice/pasta
- Large serving of vegetables or salad
- Low fat dessert or fruit.
Between meals:
- Fruit or plain biscuit (if hungry).
Drinks:
Low calorie drinks allowed freely e.g. Fruit tea, diet fizzy drinks, no added sugar squash. Hot/milky drinks within allowance (see below):
Allowances:
Per day 1 pt skimmed or 2/3 pt semi-skimmed milk.
Fat reducing summary checklist
- Always choose lean cuts of meat and trim off extra fat before cooking. Limit your portion to 2-3oz (the size of a pack of cards)
- Cook meat on a rack and allow fat to drain off
- Bake, steam, poach or grill rather than fry or roast
- Avoid using meat products such as sausages, beef burgers, pate etc. Be aware of low fat versions of these as they do still contain fat
- Use less meat and instead add bulk to sauces and stews with vegetables or beans and pulses
- Choose low-fat dairy products, such as skimmed milk, low-fat yoghurt and cottage cheese
- Eat chicken, turkey and fish more often as these contain less fat than red meat. Remove the skin from poultry
- Replace cream with crème fraiche or low fat natural yoghurt
- Choose low fat spreads instead of ordinary margarines or butter
- Avoid 'hidden' fat in foods such as pies, pastries, cakes, some biscuits, crisps, salad dressings and chocolate.
Our patients matter
Mersey Care NHS Foundation Trust listens and responds to patients and their carers to help improve the services we deliver.
If you have any comments, compliments or concerns you can speak with a member of staff or contact our Patient Advice and Liaison Service (PALS) and Complaints Team
Telephone: 0151 471 2377
Freephone: 0800 328 2941
Email: palsandcomplaints@merseycare.nhs.uk
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Approval date: 24 July 2026
Review date: 23 July 2027
Version number: 1