The anti-diet Christmas

It's the same old festive question: what can you do to shift those unwanted pounds and smooth away bumps to fit into your bignightout dress?

When it's time to get glam, celebrities undoubtedly work hard to look fit and fabulous. But although pecking at a salad and cutting carbs get results, this kind of joyless eating regime just doesn't cut it at Christmas. Here, we've asked the experts for realistic ways to get into shape for the party season.

Graze like Lucy Liu: LA-based dietician Jackie Keller heads up a gourmetfood delivery service and has recently catered for the stars of Quentin Tarantino's Kill Bill. "Lucy Liu requests five small meals a day," she says.

"Eating small and often helps you to lose weight. If the body is left too long without food it switches into starvation mode, holds onto its reserves and stores them as fat.

This way of eating helps keep blood-sugar levels constant and makes for a more revved- up metabolism."

Sneak treats: At this time of year, everybody lusts after calorie-laden foods. To trick the eye and save the hips, Keller divulges she always chops, grates or shaves foods such as nuts, cheese and chocolate, then sprinkles them on the top of or outside other foods.

"If you stir them in, your eye won't see them, so your brain won't realise you've had them," she says.

Maintain a negative calorie balance: "Eat 250 fewer calories every day and use up to 250 more than usual through exercise. This creates a weekly deficit of 3,500 calories, the equivalent of one pound of weight-loss per week," states personal trainer Kathryn Freeland, director of Absolute Fitness, and adviser to Cate Blanchett and Samantha Morton.

By eliminating a glass of wine and a chocolate bar a day (550 calories) and walking for an hour a day (360 calories), you're well on your way to shimmying into that dress.

Adopt a carb curfew: Proof you don't have to ban them à la Atkins! "It's best to avoid carbohydrates after 4pm," states Dr Nish Joshi, founder and practitioner of the Joshi Clinic, and adviser to the likes of Ralph Fiennes and Sadie Frost.

"Your metabolism starts to slow down after that time and is more likely to store the calories." Cut down on white bread, pasta and muffins - they equal empty calories and bloating. Trade for " bodyfriendly" fuel such as basmati rice, lentils and root vegetables.

Get waisted: Take inspiration from Nigella Lawson and do more to define your curves. Celebrity trainer Matt Roberts says: "For those with handles rather than muscles, try the oblique crunch." Lie on your back with one knee bent and the other leg flat on the floor.

Place your hands by your ears. Slowly raise your opposite shoulder and elbow up towards the outside of your raised thigh. Lower your shoulder and leg to the start position. Repeat 25 times each side for a total of four sets.

Go green: Drink three cups of green tea a day. "Not only does it fight free radicals, research also suggests that polyphenols may stimulate weight-loss by boosting metabolism," says Dr Joshi.

Studies at the University of Geneva in Switzerland have concluded that green tea, which has helped Sophie Dahl lose weight, raises the metabolic rate and speeds up fat oxidation.

Buy lean: "Your leanest types of meat contain the word 'loin'," reveals David Kirsch, wellness trainer and author of Sound Mind, Sound Body (Rodale Press, £14.99), who puts supermodel Heidi Klum through her paces.

"When buying meat, ignore claims that it is 97 per cent fatfree. Meat is labelled according to fat weight, not fat calories. Fat weighs much less than muscle, so a hunk of meat that's only three per cent fat by weight might be as much as 40 or 50 per cent fat as a percentage of calories."

Wave farewell to arms: "In a cocktail dress with thin straps, it's the arms everyone's going to notice," says Geri Halliwell's fitness expert Simon Waterson.

"Pleasing arms need firm triceps, but it's also shoulder-definition that helps to create the illusion of a slim figure." Along with tricep dips, Waterson advocates shoulder presses four times a week.

Sit on a chair with your back well supported and legs bent at 90 degrees. Hold weights of 3-5lb in each hand with your arms bent at 90 degrees and elbows out at shoulder level. Press the weights upwards, raising your arms above the head. Do not lock your arms straight. Pause, then lower the weights to shoulder height. Do 12 reps for three sets.

Say no to sugar: Cut out as much sugar as possible: none in coffee or tea, no biscuits or fizzy drinks. Relax, it's only for a few weeks. Sugar plays havoc with your glycaemic levels and leads to cravings.

Matt Roberts advises swapping popular breakfast cereals, nearly all packed with hidden sugars, for wholemeal toast and a poached egg.

Dine out, stay slim: "Stay away from any drink that contains an umbrella," warns David Kirsch. "It probably contains more calories than your entire meal.

As for dessert, his advice is simple: share it.

Celebrity Style Secrets. An Insider's Guide to Looking A-List, by Jacqui Ripley (Piatkus, £7.99).