The 100-Calorie Secret - Never Diet Again!

In 2005 two weight loss experts from the University of Pennsylvania's Weight and Eating Disorder Program, Dr Adam Tsai and Thomas Wadden reviewed all of the commercial weight loss programs.

The found these programs:
1. Expensive-hundreds to thousand of dollars-see table at end of article for breakdown
2. Unproven- only Weight Watchers had the minimal amount of studies
3. Ineffective- at the most a 5 lb. weight loss after 2 years

Published in the January 5, 2005 issue of the Annals of Internal Medicine, this study represents the first serious attempt to evaluate these types of programs. The editors of the Annals published a review of this landmark study. They described the components, costs and efficacy by reviewing web sites, telephone discussions with company representatives and search of all published reviews in the medical literature :

Why did the authors do this review?
To summarize what is known about major commercial weight loss programs in the United States.

How did the authors do this review?
The authors looked for studies of the following types of commercial weight loss programs:

• Non-medical programs including  Weight Watchers, Jenny Craig, and L A Weight Loss
• Very low-calorie diet, medically based programs –Health Management Resources and OPTIFAST
• Commercial Internet-based programs -Diets.com
• Non profit self-help programs: Overeaters Anonymous and Take Off Pounds Sensibly

The authors chose these programs because information about them has been published. The authors looked for studies that included adults in the United States, had more than 10 participants, lasted more than 12 weeks, and examined the program under the same conditions as it is offered to the public. The authors collected information about each program, the studies that had been done, and weight loss achieved in the studies.


What did the authors find?
Few high-quality studies have assessed weight loss programs. Many of the existing studies present the best-case scenario because they do not account for people who drop out of the program.

Of the programs the authors evaluated, Weight Watchers had the strongest studies to support it. The best study found that participants lost 5% of their initial body weight (about 10 pounds) in 6 months and kept off 3% (about 5 pounds) at 2 years.

The authors found no published high-quality studies of Jenny Craig or L A Weight Loss.

The studies of the very-low-calorie diet, medically-based programs were of limited quality. They found that patients who stayed on the program lost about 15% to 20% of initial body weight in 6 months. However, many patients dropped out of these programs. Even those who completed the program regained about half of their lost weight in 1 to 2 years after treatment.

The few studies of Internet-based and self-help programs were of limited quality and found that these approaches produced minimal weight loss.

What are the implications of the review?
With the exception of Weight Watchers, the evidence to support the effectiveness of major commercial weight loss programs is limited. Patients considering the use of commercial weight loss programs should realize that these programs have not been carefully studied and that they vary greatly in cost. "

Average initial, weekly and 3 month cost of each program:

Read the Original Study in the Annals of Internal Medicine