This is one of three Journal Notes this week that will cover studies from the Journal of the American Medical Association’s special issue on obesity.

Nearly one-quarter of Americans are overweight and another one-fourth are obese. An increasing number of these men and women are trying to lose weight and many (13% of women and 5% of men) are trying to do it through formal weight loss programs.

The public perception is that these programs do not work over the long haul. As many people see it, any weight lost is usually regained. These perceptions remain in spite of several studies that have documented modest, long-term weight loss resulting from these programs.

In a study published in the April 9, 2003 Journal of the American Medical Association (JAMA) special issue on obesity research, scientists found that Weight Watchers produced modest, but greater and more sustained weight loss, than self-help. In another article published in the same issue of JAMA, researchers found that Internet-based weight loss programs that were coupled with email counseling helped overweight adults at risk for type 2 diabetes lose enough weight to help them avoid the disease.

About the Study

Weight Watchers Study

Researchers recruited 423 adults, aged 18 to 65 years, who were overweight or obese (body mass index 27–40).

For the two-year trial, 212 of the participants were randomly assigned to a self-help weight loss program, and 211 to Weight Watchers, a commercial weight loss program. People in the self-help group were given two 20-minute consultations with a dietician, as well as publicly available information about diet and exercise guidelines for safe weight loss. The other group was given vouchers to attend Weight Watchers. The Weight Watchers program is comprised of a points-based food plan (nutritionally balanced, moderate-deficit diet designed to produce weight loss of up to 2 lb/week); an activity plan (which follows National Institutes of Health physical activity guidelines); and behavior modification (through weekly weigh-ins, social support, etc.).

The researchers compared the changes in weight, body mass index (BMI) , and waist circumference for both groups at the beginning of the study and again at year one and year two.

Internet Weight Loss Study

This study involved 92 overweight or obese adults with an average age of 48.5 years, an average body mass index of 33.1, and who had at least one or more additional risk factors for type 2 diabetes.

At the beginning of the one-year study, all participants attended a weight loss session that advised restricting daily calories to between 1200 and 1500, getting 20% or fewer calories from fat, and burning a minimum of 1000 calories per week through physical activity.

After that, 46 participants were assigned to a basic Internet weight loss program. The Web site they were referred to provided a weight loss tutorial, a new tip and link each week, and a directory of Internet weight loss resources. They were asked to submit their weight each week.

The other 46 participants were assigned to Internet behavioral e-counseling. In addition to receiving the same resources as the basic Internet group, these participants communicated via email with a weight loss counselor. They reported their calorie and fat intake, and exercise regimen. The counselor emailed the participants at least once a week, providing feedback, reinforcement, and recommendations, and answering any questions.

Weight, waist circumference, and body mass index was measured in a clinic at the beginning of the study and again at 3, 6, and 12 months.

The Findings

Weight Watchers Study

Participants who enrolled in the Weight Watchers program lost significantly more weight than the self-help group at one year (9.5 pounds (lb) versus 2.9 lb) and at two years (6.4 lb versus 0.4 lb). Waist circumference and body mass index also decreased significantly more in the Weight Watchers group.

Internet Weight Loss Study

The behavioral e-counseling group lost significantly more weight at 12 months than the basic Internet group (9.7 lb versus 4.4 lb). A ten-pound weight loss is often enough to prevent or delay the onset of type 2 diabetes in someone at risk for the disease.

The behavioral e-counseling group also had significantly greater decreases in percentage of initial body weight (4.8% versus 2.2%), body mass index (1.6 versus 0.8) and waist circumference (7.2 centimeters (cm) versus 4.4 cm).

The e-counseling participants also exercised more than the basic Internet group during the first three months of the study and reduced their consumption of fat calories to a greater extent. In both groups, those who logged in to the Web site more often lost more weight.

How Does This Affect You?

Both of these studies suggest that behavioral therapy can effectively produce sustained weight loss, which can often reduce the risk of type 2 diabetes.

The first study found enrollment in the Weight Watchers program led to greater weight loss success than self-help. However, Weight Watchers was the only commercial weight loss program analyzed in this study, so the results of the study do not necessarily apply to other commercial weight loss programs. It is important to note that this study was supported by a grant from Weight Watchers International.

The second study revealed the importance of the therapist in an Internet weight loss program, suggesting that the weekly contact, support, and recommendations a qualified therapist provides contributes a great deal to weight loss success.

Internet weight loss programs, by reducing or eliminating the need for fact-to-face contact, can be more convenient than traditional weight loss programs. This might make them a good option for the many individuals who do not have the time, inclination, or resources for traditional weight loss counseling.

When enrolling in a weight loss program, keep in mind that while the program can provide helpful guidance and support, you should be prepared to do the actual work of losing the weight.