Telephone interventions for physical activity and dietary behavior change

"Phoning it in" works when it comes to losing weight and getting fit, according to a new systematic review.

“There's an important use for the telephone in delivering support for making changes to physical activity and diet,” said Elizabeth Eakin, Ph.D., lead study author, at the University of Queensland in Australia.

The review appears in the May issue of the American Journal of Preventive Medicine.

Eakin and her colleagues in the School of Population Health reviewed 26 studies published between 1965 and early 2006. Twenty took place in the United States; the rest were conducted in Australia and New Zealand. All of the studies were randomized controlled trials.

The studies used either live telephone counselors, such as nurses, health educators or trained researchers, or automated phone systems. Researchers separated studies into three categories: those that assessed changes in physical activity levels, those that assessed changes in dietary behaviors and those that examined both physical activity and diet.

The telephone proved to be an effective delivery mechanism for health behavior change, the reviewers said. Overall, 77 percent of the studies found that people receiving phone counseling made positive dietary and physical activity behaviors.

“It shows that support for physical activity and dietary change can come from a variety of mechanisms. This is great news for people who don't want to join a more structured group program or who don't have access,” Eakin said

Sixty-nine percent of the studies that evaluated physical activity, 83 percent of the studies that evaluated dietary behaviors and 75 percent of the studies that addressed both diet and exercise reported positive improvements after the phone counseling intervention.

Although telephone counseling was the primary method of delivering information about exercise and nutrition for all of the studies, most interventions also offered participants nutrition and exercise information via an initial face-to-face meeting and printed materials.

One reviewed study aimed to increase walking. It began by offering participants detailed feedback on whether their initial level of walking was consistent with recommended levels. Counselors also provided information on ways participants could walk more each day. Throughout the study, telephone counselors helped participants set achievable goals and come up with solutions when they had difficulty meeting their goals. At the end of the intervention, researchers evaluated whether participants increased the total time spent walking from the start of the study.

Longer interventions appeared to be especially effective in helping people change their ways. Of the 13 studies that lasted between six to 12 months and included 12 or more calls, 77 percent reported positive changes in dietary behaviors and physical activity levels. In comparison, only 50 percent of the interventions lasting less than six months reported positive outcomes.

“Physical activity and diet are complex behaviors to change, so providing support over a longer period of time is more effective than short-term interventions,” Eakin said.

Despite the review's overall positive findings, few studies evaluated whether the positive outcomes of phone counseling lasted after the counseling sessions ended.

“Our big challenge as a field is to learn how to help people maintain those positive changes,” Eakin said.

Only two studies evaluated costs; both concluded that phone interventions did offer cost benefits.

Melissa Napolitano, Ph.D., an associate professor at the Center for Obesity Research and Education at Temple University in Philadelphia, said telephone counseling is not only convenient and cost-effective but it may also “be useful as it provides the accountability and social support that are important components for behavior change.”

The telephone also allows for a real-time interaction, so a telephone counselor can help people problem-solve their trouble spots, reevaluate their goals and set new goals if they're successful, said Napolitano, who was not involved in the review.

The study authors and Napolitano agreed that the phone may prove especially helpful for people with limited access to medical care or those who live in remote areas.

Eakin EG, et al. Telephone interventions for physical activity and dietary behavior change: A systematic review. Am J Prev Med 32(5), 2007.

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