Actress and singer Jennifer Hudson is a spokeswoman for Weight Watchers. (Mike Segar/Reuters)

In the British study, 740 overweight/obese adults were enrolled for 12 weeks in one of the following programs: Weight Watchers, two other commercial, group-based programs, three weight-loss programs offered through the National Health Service (including a group-based one, one overseen by a primary care physician’s office and one overseen by a pharmacy). Some of the participants were allowed to choose which program to follow, and a comparison group was given minimal supervision and vouchers to use at an exercise facility.

After 12 weeks, those following Weight Watchers had lost about three times the weight than those in the physician-supervised group (about 9 pounds versus about 3 pounds). Across the board, people lost more weight than those in the NHS programs. After a year, those in Weight Watchers had lost the most, an average of about 5 pounds more than the comparison group. There were no differences in weight loss among those assigned to programs and those allowed to choose.

The study further found that the National Health Service programs were more expensive than the commercial programs.

The findings are similar to those of another British study published in September. Both could steer British public health policy toward easing access to commercial weight-loss programs, perhaps through government subsidy of membership fees. Or, as the new study suggests, public health programs could be patterned after Weight Watchers or other commercial models, with regular weigh-ins, guidance from a trained counselor and information about healthful eating and physical activity.