Effectiveness of Cellular Phone-Based Interventions for Weight Loss in Overweight and Obese Adults: A Systematic Review

Background: In response to the rapid increase in obesity and its association with chronic diseases, World Health Organization has declared an immediate need for effective and widely-accessible interventions for weight management. Cellular phones are portable, convenient, and popular among people of varying economic status and geographic regions; hence, they offer a viable medium for delivering weight loss interventions. Objective: To determine whether cellular phones are an effective medium for delivering weight loss interventions in adults who are overweight or obese. Methods: A literature search was conducted to retrieve articles published prior to February 2012. Studies were included if they: 1) included adults with a body mass index (BMI) of 25 or higher and with no known chronic condition, 2) delivered a weight loss intervention using a cellular phone, 3) measured weight, BMI, waist circumference, body fat or any other proxy for weight loss, 4) had a comparison group, and 5) were published in English. At least two reviewers independently screened all titles and abstracts and reviewed the included articles. Results: 193 unique citations were screened; of those, six studies met inclusion criteria. Mobile interventions varied from phone calls and short message service (SMS) messaging to emails, websites and podcasts. Among studies of one-way interactive interventions (i.e., the researcher could contact the participants, but the participants could not respond), one high quality randomized controlled trial (RCT) showed a small but statistically significant effect in weight reduction, favoring the intervention, and one low quality study reported no significant difference compared to printed material. Of the four studies on two-way interactive interventions (i.e., there was open communication between researchers and participants), two RCTs demonstrated statistically significant difference for weight and waist circumference, while one showed no significant difference. When compared to a clinic-based intervention, one low quality study showed that an internet/SMS weight loss intervention was inferior to regular clinic visits. Conclusion: Due to the small number of high quality studies, modest evidence was found for the effectiveness of cellular phones in the delivery of weight loss interventions for people who were overweight or obese.