Consumers seem to have a smorgasbord of weight-loss companies to choose from, but a recent study involving a UC Davis nutritionist indicates women who devise their own weight-reducing plans may be more successful at keeping weight off than those who follow a structured program. The study, which followed 700 women who were 20 percent overweight, found that 80 percent of the women who devised their own weight-reduction plan had not put back any pounds two years later. Of the women who lost weight through structured diet programs, up to 60 percent of them had regained weight. Common features of women who succeeded at keeping their weight off were supportive family members and friends, stronger problem-solving skills and a more frequent tendency to exercise. Judith Stern, a professor of nutrition at UC Davis and a co-investigator in the study, says that women who want to lose weight should ask their doctors to help them devise a personal weight-loss plan.