Rating some top-selling diet books

You finally made the commitment and you're ready for a diet -- but what's next? Before you rush out to get the latest diet book, make sure you know what you're getting.

Nutritionist Leslie Beck has rated four of the most popular diet books on the market using a five-star system that breaks down as follows:

1 star - if the diet contains healthy foods or is nutritionally adequate
2 stars - if it's easy to follow and not cumbersome in terms of measuring
3 stars - if it educates about portion sizes and menu planning
4 stars - if it is sustainable over the long term
5 stars - if it also promotes exercise and other important factors associated with weight loss success

Beck's five-star rating is about making a lifestyle change, not a quick-fix success.

The Atkins Diet
Dr. Atkins' New Diet Revolution by Dr. Robert Atkins

"This is a low-carb diet," Beck explains. "For two weeks you basically give up carbohydrate foods. That means no dairy products, no fruit, no sweet vegetables and no starchy foods like grains, cereals or pasta."

It promotes high animal-fat foods such as meat, cream and butter, Beck says. After the induction phase, you gradually add back in five grams of carbohydrates every week. That's the cumbersome part, she explains. You constantly have to be counting all the carbs in your diet.

"Some of the drawbacks of this diet are that it's not sustainable in the long term," Beck says. "Eventually people will be adding back in carbs and what I've seen in my practice is people are doing that with high-fat foods as well. We know that a long-term intake of meat may increase the risk of colon and prostate cancer and there are experts who are very concerned that if you follow this diet for a long time, you're not getting fruits, vegetables, fibres and antioxidants, which means you may increase your risk for heart disease."

Beck's rating: 1-1/2 stars

The South Beach Diet
The South Beach Diet by Arthur Agatston

"It's a healthier version of the Atkins Diet," Beck says. "For two weeks, you eat no carbohydrates. But after those two weeks, this diet promotes the low glycemic index --  healthier carbohydrates that take longer to digest, things like fruits, dairy products and whole grains."

It doesn't promote foods that are high in animal fat. Instead it suggests fish, chicken and healthy fats.

"From that standpoint it's much healthier (than the Atkins Diet). It contains mostly healthy foods and it's easy to follow. The drawbacks of this diet is that it doesn't really educate very well about portion size when you add back in those healthy carbs."

Beck's rating: 3 stars