Dietitian Telephone Counseling Effective for Weight Loss

High-frequency telephone contact with a dietitian can be an effective method for supporting lifestyle modification in obese patients trying to lose weight, according to the results of a randomized, six-month, open-label study.

Physicians frequently prescribe medications for weight loss but offer minimal lifestyle counseling despite the additional benefits of combining both interventions,” write Andres G. Digenio, MD, PhD, from Pfizer in South Lyme, Connecticut, and colleagues. “Possible reasons for omitting lifestyle counseling may be little or no training in behavioral counseling; inability to dedicate time for ongoing counseling; lack of multidisciplinary staff; inadequate infrastructure; and costs associated with more frequent visits, which are seldom covered by medical insurance.”

The goal of this study was to compare five methods of delivering a lifestyle modification program to obese patients being treated with sibutramine at 12 independent research clinics with experience running obesity trials. With use of a computer-generated schedule of randomly permuted blocks (block length was 5), 376 obese participants (body mass index ≥ 30 kg/m2 and < 40 kg/m2) were assigned to intervention groups.

During the study, all participants were treated with sibutramine, 10 mg/day; a lifestyle manual; and access to a weight-loss website. The five interventions were high-frequency face-to-face lifestyle modification counseling (n = 74), low-frequency face-to-face counseling (n = 76), high-frequency telephone counseling (n = 76), high-frequency email counseling (n = 74), or no dietitian contact (self-help; n = 76).

The main endpoint of the study was percentage change in body weight at six months. Secondary outcomes were changes in waist circumference; lipid, glucose, and insulin levels; blood pressure; weight-related symptoms; and quality of life at six months.

The high-frequency face-to-face and high-frequency telephone groups had similar mean weight loss from baseline to six months (8.9%; 95% confidence interval [CI], 8.0% – 9.8%; and 7.7% [95% CI, 6.8% – 8.7%]), which was significantly greater vs the other groups (low-frequency face-to-face, 6.4% [CI, 5.4% – 7.3%]; high-frequency email, 5.9% [CI, 5.0% – 6.8%]; and no dietitian contact, 5.2% [CI, 4.3% – 6.1%]).

Significant improvements in waist circumference, high-density lipoprotein cholesterol and triglyceride levels, and measures of quality of life and weight-related symptoms occurred in all groups. No serious adverse events were reported, and there were no significant differences in minor adverse events among groups.

“High-frequency telephone contact with a dietitian was similar to HF-F2F [high-frequency face-to-face] contact for supporting lifestyle modification in obese patients trying to lose weight,” the study authors write. “The findings might be used by providers and health systems to promote healthy lifestyle changes for their patients.”

Limitations of this study were most participants being white women, limiting generalizability of the findings, and a high attrition rate of 30%.

“The type and frequency of lifestyle counseling support have a profound effect on weight loss,” the study authors conclude. “Participants lost the greatest amount of weight when exposed to frequent face-to-face contact with a dietitian and lost the least amount of weight when they had no dietitian support. Dietitian counseling over the telephone emerged as an effective alternative to face-to-face counseling in combination with pharmacologic treatment.”

Ann Intern Med. Feb. 17, 2009; 150:255-262.