THERE comes a turning point over the Christmas period when eating becomes a duty and not a pleasure. Who would think that one could ever tire of bumper size packs of party nibbles from Marks and Spencer or mince pies drenched in brandy butter? But the day inevitably arrives, as you slump on the couch, resting a post-prandial glass of Irish Mist on your paunch, when you begin to crave steamed green vegetables, washed down with litres of spring water and slices of lemon. 2007, the nation collectively proclaims, is the year we're going to lose weight.

The only problem with this admirable sentiment is that January is the worst month in which to start a diet. We're broke; suffering the most terrible postChristmas comedown and the weather is appalling.

The month might start with the most zealous of healthy eating plans but more often than not, the sheer grimness of January undermines them and the rationale goes that if we can't go out, drink or spend money, surely we're allowed to find some solace in comfort eating. And we can always start again in February, when the weather is that bit more conducive to exercise and everything is a bit less depressingf This sense of feeling deprived and bored are dieting's greatest enemies. In theory, most of us know the principles of weight loss . . . eat less, exercise more . . . but of course if it were only that easy, the current obesity problem in Ireland, (where more than one in two Irish adults are either overweight or obese) would not exist. But if you've run the whole gamut of diets, starting with Atkins and ending with low GI, where to next?

The latest diet promising to return you to svelteness avoids the usual dietary pitfalls by allowing you to eat tasty food without starving yourself or cutting out any important food groups, while still allowing you to lose weight over a 90-day period.

The Fat Smash Diet by Dr Ian Smith, an American nutritionist with a celebrity client list, is on the New York Times' bestseller list, has become a cult favourite in the States, and is set to cause a similar flurry of interest here. Smith devised the diet for the TV show Celebrity Fit Club with dramatic results for the participants.

Actresses Kelly LeBrock lost a whopping 31lb and Cher's daughter, Chastity Bono, lost 24lb, and viewers, eager to emulate their success, placed their orders for the book and thus a new diet phenomenon was born.

"Diets don't fail people; people fail diets, " Smith maintains. There's nothing very alarming or particularly faddish about this diet, although it does require some meal planning.

The emphasis is on slow-release energy foods like brown rice, as well as portion control and daily exercise. Tea, coffee and alcohol are banned, as are potatoes and avocados, but all other vegetables are allowed, as are fruits, beans, porridge and yoghurt.

It works in four phases over 90 days.

The first phase is the most difficult. This is a nine-day detox where five small meals a day are consumed (fruit, vegetables, cereals and selected proteins) and all food must be raw, grilled or steamed.

Phase two, which lasts for three weeks, sees more lean meats and cheese introduced. In phase three, portion size increases and the occasional treat is also allowed. By the time you reach phase four, many of the forbidden foods are reintroduced, but Smith maintains that by this stage, you will have 'smashed' bad eating habits and you won't overindulge in these foods. This is a template for life, he believes.

Does it work? Yes, in the same way that most diets work, provided you follow them. But the real advantages of the Fat Smash is that because you're eating a little and often, you shouldn't get ravenously hungry; the diet itself is healthy even though it is restrictive in phase one.

The suggested foods can be found in a supermarket and aren't prohibitively expensive, unlike some diets like South Beach, which instructs you to eat fresh fish almost on a daily basis.

It's also a diet which seems to achieve as good a set of results for those who have a little to lose (say 10lb) as it does those who need to lose 100lb and followers report pretty dramatic results (up to 9lb) in phase one.

But most enticingly of all, the Fat Smash diet is new. If we are going to try and lose weight this January, we might as well try the diet with the greatest novelty factor and a reasonable rate of success 'The Fat Smash Diet' (Vermillion) by Ian K Smith is out now

DR IAN SMITH'S TOP TIPS

>> Try frozen seedless grapes. Put the grapes in the freezer, then grab them as you like. They're delicious and they're low in calories.

>> Never eat within an hour and a half of going to bed. Try going for at least a 20- or 25minute walk after dinner or participate in some other type of physical activity. This will help rev up your metabolism and burn off those calories before going to bed. It also releases endorphins, special chemicals in the body that make you feel good.

>> Eat foods high in fibre. Studies have shown that fibre helps to make you feel full longer, delays hunger pangs, reduces cholesterol levels, reduces constipation, reduces the risk of heart disease and potentially helps prevent some intestinal cancers. Dietary sources of fibre include whole grains, fruits, vegetables, nuts and seeds.