If you want to shed those Christmas kilos, a New Year crash diet is the last thing you need. Eat three square meals a day and choose the right work-out

The unfortunate truth is that if you've had a good Christmas, and seen in the New Year with style, chances are you've put on a good few pounds. Not only is the nation's collective waistband tighter, but those two weeks in front of the television, when our only exercise was the walk to the fridge, have left us feeling decidedly sluggish.

The unfortunate truth is that if you've had a good Christmas, and seen in the New Year with style, chances are you've put on a good few pounds. Not only is the nation's collective waistband tighter, but those two weeks in front of the television, when our only exercise was the walk to the fridge, have left us feeling decidedly sluggish.

As always at this time of year, a veritable bun fight is going on in the diet book publishing world. One guru will tell you to avoid fat, while another will advise you to lap it up. One allows almost a bottle of red wine a day, another bans watermelon and cooked carrots.

The reality is that there is no magic cure, and what we've known all along still stands - if you consume fewer calories and exercise more you will lose fat. Whether you keep it off depends on whether you alter your lifestyle permanently.

The good news, however, is that providing you put your mind to it, losing those excess pounds and feeling generally healthier, is not difficult, as the experts explain below. Always consult your doctor before starting a new regime.

Diet: If you are a normal weight, and have gained a few pounds over Christmas, the worst thing to do is diet, says the British Dietetic Association. ''If you diet you could easily set up this binge/diet cycle that so many women get into,'' warns the health body's vice-chairman Luci Daniels.

"There is no quick-fix way to lose weight. We know that people who try all different diets end up weighing more than when they started. The thing to do is cut out the extras and get back to a regular meal plan, with a breakfast, lunch and dinner, and try to get into a regular exercise routine. You will lose those extra pounds in a few weeks without feeling miserable, guilty or hungry and getting obsessive about food.''

Those who are overweight, and wish to do something about it, should go on a well-balanced weight-loss plan, aiming to lose one to two pounds a week. Three meals, perhaps with a small snack mid-afternoon, are advisable. High fat and high sugar foods should be cut back and regular exercise taken.

A typical breakfast would be cereal with a slice of toast. Lunch could be a sandwich or a jacket potato with a low-fat filling and salad, and a low-fat yoghurt and fruit. Those wanting a snack could opt for fruit and a yoghurt, a slice of toast, or a couple of crackers with low-fat soft cheese. Dinner could be meat, chicken or fish, with potato, rice or pasta, vegetables and some fruit. People can treat themselves daily to either a fun-sized chocolate bar, a bag of low fat crisps, a scoop of ice-cream, or a few biscuits.

Daniels says the British Dietetic Association would never recommend "detoxing" of the kind that Leslie Kenton recommends (below). ''Detoxes are quite low in calories and leave you hungry. Probably the best way to clear your mind is to get a bit of sleep and have a few days without any alcohol. Make sure you are drinking enough fluids and try to establish a regular meal plan.''

Detox: According to health writer Leslie Kenton, Christmas blow-outs are not only perfectly natural, but good for you. ''Part of Christmas for most of us is feasting and overindulgence,'' she says. ''This, for me, is a normal part of human existence, a kind of Dionysian Rite where we loosen the bounds of control and celebrate our wilder nature. It is good for the spirit and connects us with others in a wonderfully communal way.''

But there is, of course, a downside. ''The problem is, it is not good for the body long-term. Too much fat and sugar, too much alcohol and coffee, and too little sleep build up toxicity in the body in the form of acid wastes that undermine our energy, and interfere with the smooth running of the body's metabolic processes. If they are not cleared periodically, they make us prone to early ageing and degenerative conditions from rheumatoid and osteo arthritis to cancer, heart disease, diabetes and even depression and anxiety.''

The solution, according to Kenton, is to detox the body. ''Clear out the junk and you are reborn anew,'' she promises. In Detox Now, published by Vermilion today, the high priestess of health suggests a weekend detox regime of eating nothing but apples, including the peel, seeds and core. The only drink permitted is herbal tea or spring water.

To help with the detoxification process, Ms Kenton advises participants to indulge in skin brushing, Epsom salts baths and long walks. For the first two or three days after the fast only raw food should be eaten, particularly fruit. Ms Kenton says her apple fast should be avoided by those who are pregnant, breast-feeding, or who suffer from kidney, liver or heart complaints.

Exercise: Those seeking to look slimmer as fast as possible should try the toning-based exercise called Pilates, advises personal trainer Emily Kelly.

Kelly, who helped model Sophie Dahl reduce from a size 14 to a 10/12, says Pilates not only greatly benefits the lower abdominals but also has a dramatic effect on posture. ''The minute your posture changes you can instantly appear to have lost up to about 5lb. So if you are looking for instant results then Pilates would be the one to go for,'' advises the 24-year-old from North London.

As well as at least two toning sessions a week, those seeking to lose excess fat should also take up cardio-vascular exercise. ''You need to be aerobically training three to five times a week, from 20 to 60 minutes,'' says Ms Kelly. ''But if you keep to 20 minutes, you will probably only maintain your weight - you need to be aiming more for five times a week if you are looking to actually drop a couple of pounds.''

One current popular workout is Khai-Bo, which is similar to boxercise but also works the legs. Those not able to fit classes into their lifestyles can buy a punch bag (some are free-standing and require no drilling), and hire a personal trainer for six to 10 sessions to learn the basic jabs and kicks.

"It does sound a bit boring doing it at home, but it's actually really good fun,'' says Ms Kelly. "Because you are concentrating so hard on learning the moves it tends to keep boredom at bay. It's also incredibly therapeutic - you are releasing a lot of tension. And you get fast results. It's fantastic for fat-burning.''

Other alternatives to joining a gym include hiring or buying cardiovascular equipment; taking up a team sport; putting on music and dancing for an hour; or buying an exercise video.

She suggests that those fit enough to try running should put aside an hour, to include a warm-up and warm-down. After stretching, walk for three minutes, and then run for three minutes. Then continue walking for one minute and running for three minutes. The following week, run for four minutes and walk for one minute. Add a minute each week to the running time. At the end of the run, walk for three minutes and then repeat the stretches, holding them for longer.

Emily Kelly can be reached on 0958 412662.