January is the most popular time of year for people to start crash diets, hoping to shed those extra Christmas pounds. But before you start cooking that cabbage soup, it's important to decide which diet is right for you and your lifestyle. Marie Madden discusses four of the most popular.

South Beach Diet

Nicole Kidman, Kim Cattrall and Hillary Clinton are all reported fans of this diet, which is largely based on the glycaemic index. Dieters cut carbohydrates from their diet before slowly re-introducing them. Advantages of this diet include the fact that it is very simple and doesn't require much counting or measuring. Instead, followers choose foods from within a certain list. The diet is also low in saturated fats and encourages the person to become aware of the effects foods have on their body.

However, the first phase of this diet is very restrictive and may turn people off sticking to it. It is also fairly loosely structured in places, leaving a lot of choices up to the dieter, which can sometimes prove hard for the less motivated follower.

The Atkins Diet

The Atkins Diet has been one of the most popular diets in Hollywood for a number of years, with Calista Flockhart, Jennifer Aniston and R?nee Zellweger all following the low-carb diet. This diet states that you can change your metabolism and lose weight easily, by eating foods high in protein and fat and limiting foods high in carbohydrates.

This diet has caused a lot of controversy over its long-term effects. The pros include the inclusion of usually forbidden foods, such as steak and butter, and it is also quite simple to follow. One of the main advantages of the diet is that it emphasises finding your own carb level as different people have different sensitivities. Information is also freely available due to the popularity of the diet.

However, many doctors have slammed the induction phase of Atkins as dieters can experience 'carb crash', where people experience negative reactions to the lack of carbohydrates. It can also be hard to get all your necessary nutrients on an extremely low amount of carbohydrates and, unless the dieter is very creative, a low carb diet can get very boring.