As online weight loss programs (e.g., eDiets, weightwatchers.com) continue to grow in number and popularity, researchers are already moving on to the next technology - podcasting. Podcasting, or audio files for a portable music player or computer, have been around for about five years. Podcasts differ from the internet in that they are very portable and don't require users to be literate or able to process/understand written information.
To test whether weight loss podcasts can produce significant weight loss, researchers at The University of North Carolina at Chapel Hill randomized 78 overweight study participants to receive 24 episodes (15 to 20 minutes each) of a currently available weight-loss podcast or a weight-loss podcast based on constructs from the social cognitive theory of behavior change including expectations (for weight loss), building self-confidence (for changing weight-related behaviors), and increasing knowledge (about how to lose weight and change behaviors).1
At three months the "enhanced" (social cognitive) podcast listeners lost an average of 6.4 pounds whereas the "control" (currently available) podcast listeners only lost an average of 0.7 pounds. Participants in the enhanced group also reported greater increases in fruits and vegetables and a greater increase in the number of days engaged in vigorous physical activity compared to the control group.
What was interesting is that the majority of participants in the study reported listening to the podcasts at home (while sitting) most often, followed by in their office and at work (while sitting at their desk). Only 13% reported listening while walking or exercising. Thus, future interventions may need to do more to encourage participants to take advantage of the portability of podcasts.
All in all, weight loss podcasts can produce weight loss, but ones that are based on behavior change theory seem to be more effective. Thus, if you are considering enrolling in a weight loss program with podcasts ask if it addresses things like the importance of achieving a healthy weight; what to expect from trying to lose weight; goal setting and tracking weight, calorie, and physical activity behaviors to increase confidence; and basic knowledge about how to lose weight, exercise, and make lasting dietary changes.
1Turner-McGrievy, G.M. (2009). Pounds off digitally study: a randomized podcasting weight-loss intervention. American Journal of Preventive Medicine, 37(4), 263-269.