Eating out is a lovely idea. After all, someone else does the work (and they wash up too!) and it's a little time out to catch up with friends or family. BUT what if you are watching your diet closely. How can you eat out and stay on track?

Takeaway foods are traditionally fried, heavy in fat and a potential problem for anyone seriously wanting to curb fat intake. A portion of fried chicken and chips can deliver a whopping 47g of fat – around two-thirds the amount needed by most people in a day. A meat pie weighs in at around 24g fat, whereas a salmon and salad sandwich may only give you 12g. Even a serving of french fries will debit your diet with 20g of largely unnecessary fat.

Some takeaway foods can be suitable if you check carefully.

* Lebanese doner kebabs offer a balanced meal of meat, bread and salad - but check that the meat is not heavily laced with preservatives and flavours.

* Look for salads (but make sure the mayonnaise or dressing is low fat and free of additives). Many salads have a long shelf-life which means they have a fair dose of preservatives in them.

* Yoghurt (reduced or lowfat) is an option, particularly if teamed with fresh fruit.

* Ask for sandwiches to be spread with mayonnaise or avocado, a minimum of butter or none at all.

* Some health-food takeaways have pies, tofu-burgers or health rissoles that are good value nutritionally. Check that they do not contain too much fat, and that they are made with natural ingredients. But beware, some 'health' foods in trying to emulate meat become decidedly un natural.

* Buy a plain wholemeal bread roll from a baker, some salad ingredients from a market and build your own sandwich.

* Fresh fruit is always great – just wash the skin to remove chemicals.

When eating at restaurants, the task for those watching both weight and health is now a little easier. Most menus have enough flexibility that diners can order foods to suit a lower fat diet.

* If you are unsure of the content of a dish or how it is prepared or served, ask the waiter. It is their job to know or to find out. Don't be hurried into choosing something which does not suit your eating plan. Explain your needs so that they can suggest alternative dishes.

* Watch out for wine and alcoholic drinks which can add kilojoules easily. Ask for a glass of water to accompany the meal so that you are not tempted to over-indulge.

* Ask that sour cream or butter be omitted from the potato order and refuse the butter pat with the bread roll.

* Watch those dressings, mayonnaises and sauces too. Ask for them separately so you can add as much (or as little) as you wish. And while extra virgin olive oil is very good for you, from a heart-health point of view, its kilojoules will still boost your intake too high if you have too much. Use it sparingly.

* For main courses, stick with plain grilled fish or skin-removed chicken and simple salads and vegetables. That way you can see what you are getting and the fat content will be reasonably low.

* Smorgasbords (if you can resist the temptation to binge-eat) are great as you can eat very small amounts of some things and load up on salads.

* Realise that you do not have to eat everything on your plate. At the beginning of the meal, 'serve yourself', by putting to one side the amount you do not plan to eat. That way you won't forget and suddenly find you have eaten it all. You can always ask for a 'doggie-bag' to take the remainder home to enjoy the next day.

Lowering fat in the diet requires determination, intelligence and diligence. It is made doubly difficult by the temptations we see at every turn, yet by avoiding highly fatty foods, limiting our intake to under 30% we may avoid some of the world's most deadly and insidious diseases.

Low in fat our diets may be, but they don't have to be boring – and we can still get on with our social life as well.

- Sally Hammond

What is your favourite healthy dining out tip?