Weight Watchers offers two programs: the points program and, more recently, the core program.

The well-known points program simplifies a diet that measures a person's caloric intake and energy expenditure.

How Does Weight Watchers Points Work?

Instead of having to count calories yourself, Weight Watchers assigns a specific number of points to various foods based on their nutritional content - and a negative number of points to specific exercises. Dieters must merely stay on or below their total point value for the week, which is determined by the program.

Support groups also meet regularly, helping dieters achieve their ideal weight through counseling.

How Does Weight Watchers Core Work?

The newer core plan defines certain "core" foods and indicates that dieters can eat such foods until satisfied but not full. Non-core foods, again given set points by the program, can be consumed up to a designated total of non-core points.

Benefits of Weight Watchers

Followers of the Weight Watchers points diet can lose or maintain weight without drastically altering what kinds of foods they eat. The diet doesn't forbid certain foods, but instead allows dieters to eat what they please, but in moderation. Exercise also provides flexibility, allowing the follower to eat more (taking in more points) if they are active (removing points).

Review of Weight Watchers

"It's probably the best one out there," says dietician Barker Jackman of the Weight Watchers diet. Although she only supports this diet so long as followers don't abuse the points system.