If you want to lose weight, you may consider engaging in regular physical exercise as well as a structured weight loss program, such as Jenny Craig or Weight Watchers.
Two new studies demonstrate that when used in conjunction with one another, these kinds of interventions do work for adults who are overweight or obese. Prior to the publication of these studies, there has been a lack of scientific evidence for the vast majority of commercial weight loss programs.
In the first study, Bret H. Goodpaster, Ph.D., from the University of Pittsburgh School of Medicine and colleagues, randomized a group of 130 severely obese adult individuals without diabetes in two groups to assess weight loss for a period of one year.
One group was randomized to diet and physical activity for the entire 12 months, while the other group had the identical dietary intervention, but with physical activity delayed for six months. The study was conducted from February 2007 with follow-up through April 2010.
To help subjects stick to their diets and improve the chances of weight loss, the researchers provided pre-packaged meals to the group at no charge throughout the study. In the first three months, this included all but one meal per day. During the next three months, it included only one pre-packaged meal per day.
Physical activity consisted of brisk walking up to 60 minutes, five days a week. Participants were provided with a pedometer and encouraged to walk at least 10,000 steps a day.
Small financial incentives for adherence to the behavioral goals of the intervention were also provided. The participants received a combination of group, individual and telephone contacts as part of the lifestyle intervention.
The group that started with the diet and physical activity lost more weight in the first six months than the delayed-activity group (about 24 pounds as compared to 18 pounds).
However, the authors report that weight loss at 12 months was about the same in the two groups (almost 27 pounds versus about 22 pounds).
“Waist circumference, visceral abdominal fat, hepatic (liver) fat content, blood pressure and insulin resistance were all reduced in both groups,” according to the authors.
“It is also clear that physical activity should be incorporated early in any dietary restriction approach to induce weight loss and to reduce hepatic steatosis [fatty liver] and abdominal fat,” the authors wrote.
In the second study, Cheryl L. Rock, Ph.D., R.D., from Moores UCSD Cancer Center and colleagues, conducted a randomized controlled trial of weight loss and weight maintenance in 442 overweight or obese women (BMI, 25 – 40), ages 18 to 69. The women were followed over a two year period with follow-up between November 2007 and April 2010.
The women were randomized into three intervention groups. The first group consisted of in-person, center-based (167 women) weekly one-to-one weight loss counseling, including free-of-charge prepackaged prepared foods (from Jenny Craig, Inc.). They were also asked to engage in physical activity for 30 minutes a day, five days a week.
The second group was the same as the first group, except instead of in-person counseling sessions, the sessions were telephone based (164 women).
The third group was the usual care group (111 women) who received two individualized weight loss counseling sessions with a dietetics professional, as well as once-a-month contact.
The average weight loss for the women participating in the center-based group was about 16 pounds or 7.9 percent of their initial weight, about 14 pounds or 6.8 percent for the telephone-based group, and about 4.5 pounds for the usual care control group.
“By study end, more than half in either intervention group had a weight loss of at least 5 percent compared with 29 percent of usual care participants,” the authors report.
“Findings from this study suggest that this incentivized structured weight loss program with free prepared meals can effectively promote weight loss compared with usual care group,” the authors comment.
“Importantly, weight loss was largely maintained at two-year follow-up.” They note that even small percentage weight changes can result in a reduction of risk for cardiovascular disease and diabetes.
However, today most commercially-available weight loss programs are not covered by health insurance in the U.S.
“Currently, insurance companies will often cover the cost of bariatric surgery for obesity (estimated at $19,000 – $29,000 per patient from insurance reimbursement data) but do not cover the cost of commercial weight loss programs (such as that evaluated in this study, with estimated costs of approximately $1,600 for 12 weeks of the program and for food.),” notes Rena R. Wing, Ph.D., from the Warren Alpert Medical School, Brown University.
“Providing commercial weight loss programs free to charge to participants might be a worthwhile health care investment.”
Obesity is among the most significant public health problems of the 21st century and the prevalence of obesity has been rapidly rising for the past three decades, especially among African American women. National statistics indicate that the prevalence for overweight and obesity combined (having a body mass index of 25 or greater) is 68 percent of the population.
People who are overweight or obese are at increased risk for a number of medical problems, including diabetes and high blood pressure.
The articles appear in the October 27 print issue of JAMA.