An article published in the March 12 issue of JAMA reports that monthly personal contact with a weight loss counselor helped weight-loss program participants sustain their weight loss. Often just a brief 10-15 minute phone conversation, this personal contact intervention proved more effective than a Web-based intervention or a self-directed program.
To motivate the study, the authors mention that about two-thirds of adults in the United States are overweight or obese. “Together overweight and obesity are the second leading cause of preventable death, primarily through effects on cardiovascular disease (CVD) risk factors (hypertension, dyslipidemia [abnormal amounts of lipids and lipoproteins in the blood], and type 2 diabetes). Weight loss improves these risk factors, and evidence suggests that benefits persist as long as weight loss is maintained.”
It is common for adults to regain weight even after a four to six month behavioral intervention that leads to significant weight loss. The authors note: “Given the vast scope of the overweight and obesity epidemic, there is a critical need for practical, affordable, and scalable intervention strategies that effectively maintain weight loss.” Although there are clear benefits to maintaining weight loss, “there is little evidence, particularly from clinical trials, on how to accomplish this objective.”
The study was conducted by Laura P. Svetkey, M.D. (Duke University Medical Center, Durham, N.C.) and colleagues, and is called the Weight Loss Maintenance (WLM) trial. The researchers’ aim was to test various strategies for maintaining weight loss over a period of 30 months after a large, diverse, adult population lost weight. There were two phases in the trial. First 1,032 overweight or obese adults at risk for CVD with hypertension and/or dyslipidemia (elevated lipids in the blood) lost weight during a 6-month weight loss program. Those who lost at least 8.8 lbs. during the program were randomized to a weight-loss intervention for phase two. The sample consisted of 38% African American and 63% women.
The researchers compared three interventions:
- Monthly personal contact – participants had telephone contact with an interventionist for 5 to 15 minutes each month and 45- to 60-minutes face-to-face contact every 4th month
- Unlimited access to an interactive technology – access to a Web site designed to support weight loss maintenance, interactive features that help set personal goals and action plans for the next week, and graphs of personal data over time
- A self-directed control – participants received minimal intervention
The participants averaged 213 lbs. at the beginning of the study and lost and average of 18.7 lbs. during the first 6-month program. Although all groups regained some weight after randomization, those in the self-directed control gained an average of 12.1 lbs. those in the technology intervention gained about 11.5 lbs., and those in the personal contact group gained an average of 8.8 lbs. After 30 months, the average weight in each group was lower than the average weight at the beginning of the study.
Thirty months after assignment to one of the programs, those in the personal-contact group regained an average of 3.3 lbs. less weight than those in the self-directed group. Participants in the Web-based intervention regained only 0.7 lbs. less than those in the self-directed group. Comparing the personal-contact group to the technology-based group, the former regained an average of 2.6 lbs. less than the latter.
Of all study participants, 41.8% were able to maintain at least 8.8 lbs. of weight loss compared with entry weight, and there were no significant differences between intervention groups. Almost 71% remained at or below their entry weight.
“Although weight regain with the personal-contact intervention was statistically less than weight regain in the self-directed control group, the [average] effect was a modest 1.5 kg [3.3 lbs.] at the end of the study. However, even modest weight loss can improve cardiovascular risk factors. Each kilogram [2.2 lbs.] of weight loss is associated with an average decrease in systolic blood pressure of 1.0 to 2.4 mm Hg and a reduction in incident diabetes of 16 percent,” note the researchers. “At the end of the study, more than 45 percent of those in the personal-contact intervention were still maintaining at least [8.8 lbs.] of weight loss, an amount with clear clinical benefits.”
They conclude: “Future research should focus on longer intervention and follow-up, understanding predictors of successful maintenance and further refinement of both personal-contact and interactive technology-based interventions.”
JAMA. (2008). 299(10):1139-1148.
Written by: Peter M Crosta