Already failed at your new year's resolution to lose some weight? Haven't been able to muster the determination to start your diet yet?

If so, don't despair. The latest research from WeightWatchers has found that most people don't even get serious about their diets until mid-January anyway – after they've polished off all the leftover Christmas chocolates and cake.

Nearly three quarters of us plan to change our diet or fitness regime this year, according to a recent survey for British Lion Eggs.

The first problem with starting any diet is deciding which one to try: calorie-counting, high protein, high fibre, low GI, low fat, food-combining, no carbs, cabbage soup or the eat-every-13-minutes diet?

More importantly, which one actually works? Almost certainly one that takes a long-term rather than a crash approach, warns the Food Standards Agency.

"The promise of super-fast results may be tempting," says FSA nutritionist Sam Montel, "but extreme diets don't work in the longer term and aren't good for your health.

"The best approach to achieve a healthy weight or generally improve your diet is to adapt your lifestyle gradually. That way, it's more likely that by the end of the year you'll still be following your new good habits."

She advises people to eat a healthy balanced diet, drink plenty of water (we need about six to eight glasses of fluid a day) and start getting active.

That's easier said than done, as millions of us can testify – which is the second problem with starting a diet, sticking to it.

We all know what we should be doing, yet a quarter of UK adults are already obese – and the figures are swelling. If current trends continue, by 2050, a staggering 60 per cent of men and half of women will be obese, with serious health implications.

Two of the biggest weight loss names – Weight Watchers and the Atkins Diet – hope to help us lose weight with new diet initiatives which also include exercise plans.

WeightWatchers, the world's biggest diet organisation, has just launched the Discover Plan which it claims will help you feel fuller for longer. It's based on four principles: eating more filling foods; learning how to listen to your body (so you stop eating when you're full); emotional training (so you don't reach for the biscuit tin when you're stressed) and getting more active.

The All-New Atkins Advantage Diet follows same principle as the original high protein, low carbohydrate plan, but is more flexible and allows you to eat some carbs such as bread and pasta. It also includes an exercise plan.

The original Atkins Diet was criticised for encouraging people to eat unhealthy amounts of protein and fat, although plenty of people – including many celebrities – loved the diet.

After a two year study, the new Atkins plan was ranked by the American Medical Association as top for overall weight loss.

Whichever diet you follow, we think these health tips (which came from Atkins) make good sense:

- Drink plenty of water. People sometimes confuse thirst with hunger and end up consuming extra calories.

- Try not to use food to cope with stress.

- Eat healthy protein. Atkins says that this is more satisfying and filling than carbohydrates or fats.

- Manage your snacking or you'll eat far more than you realise.

- Consider whether you're really hungry before eating and don't overeat. Your stomach is only the size of your fist, so it takes just a handful of food to fill it comfortably.

- Sleep regularly. When you're sleep-deprived, you crave food.

- Be physically active. The best way to burn calories is to increase your levels of physical activity. Here's a rough guide: 60 minutes of gardening burns 300 calories; 60 minutes of walking burns 200 calories; 90 minutes of playing football burns 600 calories and 45 minutes of dancing burns 450 calories.