So it's not the most comprehensive weight-loss Q&A in the world - but it does have the answers to those old chestnuts we so often wonder about.

Q: Butter Or Margarine?

A: Butter is made by churning cream. There are no other ingredients, although salted butters typically have 1.5 to 2 per cent salt added. Butter lovers defend their favourite spread by saying that it is natural and contains no additives – and how no margarine or dairy spread has yet managed to emulate its creamy taste. The new spreadable butters have been whipped or have sometimes had the hard fat removed – but they are as high in saturated fats as the original.

All of the other spreads in the refrigerator section at the supermarket are highly processed mixes of water, vegetable oils and additives blended with emulsifiers and flavoured with whey or, sometimes, butter itself.

Choose a spread which has no more than 15 grams of saturated fat per 100 grams and look for labels which claim that the product is either high in polyunsaturates or monounsturates. Manufacturers need not state the trans fatty acid content unless they claim their product is ‘low in trans fats’. The average spread has five to seven per cent.

Ordinary margarine, whether it is polyunsaturated or not, has the same total fat content as butter (about 80 per cent), so look for a reduced-fat label if you want fewer calories.

Q: Vegetarian Or Meat-Eater?

A: There are definite health advantages to be gained from switching to meat-free eating. Some studies have shown that risk of heart disease, the nation’s biggest killer, is one third less for veggies, and eating less red meat (and therefore less saturated fat) is also thought to lower blood pressure and to reduce the risks of some cancers. In fact, the National Cancer Research Institute in Tokyo showed that women who eat meat daily have almost a four times greater risk of getting breast cancer than those who eat no meat.

Also, one 11-year study of 11,000 people at Oxford University, published in the British Medical Journal, found that a vegetarian diet can reduce the risk of cancer by up to 40 per cent. Since vegetarians also tend to eat less saturated fat (which comes mainly from animal sources) and more fibre, they also record lower blood cholesterol levels and, therefore, their risk of heart disease drops.

Vegetarians also have a lower risk of getting gallstones and diverticular disease, according to researchers. If you think it is for you, the Vegetarian Society recommends gradually replacing animal foods with meat-free products. “Always check food labelling for ingredients, and look for the words ‘suitable for vegetarians’, or better still, the Vegetarian Society logo,” says a spokesperson for the Society.

Q: Takeaway Or Cook At Home?

A: Even the most health-conscious among us now gets around one quarter of our daily calories from takeaway foods. Very often the easiest thing to grab after a training session is a burger and fries or fish and chips. But are they doing us any good at all? While many of these meals are well publicised for their high fat and sodium content, it seems that fast foods as a whole are somewhat unfairly maligned as junk food. In fact, choose carefully and life can be healthy in the fast-food lane. Here’s a brief guide to what’s hot and what’s not.

Burger And Fries This accounts for one in five of all takeaway meals in the UK, and McDonalds alone serves 13,000 customers a minute worldwide. Most of the big chains have had a health drive in recent years and have switched, for instance, from using saturated fat to vegetable oils for frying foods. Burgers rarely contain additives these days either. The disadvantages of a burger and fries are the fat content (a typical portion contains 42 per cent fat), the low fibre count and the fact that it contains enough sodium to fulfil the average person’s daily requirement. To cut fat, stick to small portions of thinly-fried chips (which soak up more fat than normal chips because of their larger total surface area) and avoid salads soaked in oily dressings. Ask for a large burger without mayonnaise (which adds 11 grams a tablespoon) and melted cheese and you’ll save 200 calories. For a drink, choose orange juice or water rather than fizzy drinks which contain little more than sugar and water with virtually no nutrients.

Doner Kebab Most of the bad publicity for the kebab centres around the fact that if meat is kept warm for a long time, it harbours the risk of food poisoning. Sometimes, cheap cuts of fatty meat are used to make kebabs – look closely and you can see the globules of fat in the reconstituted meat. But in a good-quality kebab shop, you can eat a fairly balanced meal. Served with salad in pitta bread, a kebab is a good source of protein, zinc and iron.

Fish And Chips The big problem here, obviously, is fat. Depending on portion size, fish and chips will provide one third of your daily fat requirement in one fell swoop, and usually it is the unhealthy saturated variety. Some shops have switched to using vegetable oil, but the only way to find out what sort of fat is used is to ask. Still, the nation’s favourite fast food does have some good points. Fish, of course, is an excellent source of protein, vitamin D and B12. And if it is cooked when the oil is very hot, the batter won’t absorb too much fat. To reduce fat, peel off the batter. Chip shop chips are actually a better choice than the thin-cut fried ones because they’re less fatty and a deep-fried, thick-cut chip retains more vitamin C than a boiled potato of the same size.