Weight Watchers was named the best weight-loss diet by the U.S. News and World Report. The diet was also named the easiest to follow and the best commercial diet plan.

Launched in 1963, Weight Watchers has become an increasingly popular diet for its simplicity and emotional support offered through group meetings. The popular dieting regime is based on a point system, which monitors food intake while still giving dieters the freedom to balance healthy choices with guilty pleasures.

It's very user friendly, and allows people to go out to eat and live like a human being, Keith Ayoob, director of the nutrition clinic at the Rose F. Kennedy Center at the Albert Einstein College of Medicine, told ABC News. It's got enough flexibility to be tailored to the kind of person you are.

As a member of the Weight Watchers program, each person is given a PointsPlus target, a number based on gender, weight, height and age. Over 40,000 foods have been given points in the program and dieters can stick to their target number by counting points.

Dieters are urged to avoid processed foods and to eat large quantities of fruits and vegetables, which have zero points. Besides these two guidelines, the rest of a member's diet is dictated by the point system.The program also offers group meetings, weigh-ins, recipe suggestions and behavioral counseling.

Weight Watchers one of the big winners here. It has so many good attributes, Katz said. It's easy, they make the monitoring easy, and it is a structured program. You don't have difficulty finding right foods and the program also lends you support.

Five Things to Know About the No. 1 Diet for Losing Weight in 2012:

1. No foods are off limits. Weight Watchers is one of the few diets that does not limit food groups and allows dieters to eat whatever they want. The only restriction in the Weight Watchers diet is that dieters are required to stick to their PointsPlus system. Dieters can eat philly cheese steaks and sugar cookies, but they will have to compensate by eating healthier meals later. In addition, dieters rarely complain of feeling hungry because Weight Watchers emphasizes foods heavy in fiber and gives dieters 49 extra leeway points.

2. Because no foods are off limits and dieters have relative freedom in the program, Weight Watchers is relatively inexpensive in terms of food costs. However, participants in the program are required to pay $39.95 to attend unlimited meetings and to access the eTools. A 3-month online only plan is $65. The program has no fixed membership so dieters can quit whenever they would like.

3. Weight Watchers is an easy program to follow because you can always check the point value of foods you are eating. The program offers a pocket guide, pocket calculator and a PointsPlus iPhone app.

4. While some diets do not incorporate exercise into the diet program, Weight Watchers is unique it that it attributes points to a number of activities like running, swimming, cleaning, dancing and working around the house. These points count as extra food points that can be splurged on a beer or extra slice of pizza.

5. While there is no conclusive evidence that the Weight Watchers program promotes heart health or prevents diabetes, losing weight through the program can help prevent disease.