Pounds Off Digitally (POD) Study: Using podcasting to promote weight loss Brie Turner-McGrievy, MS, RD Doctoral Candidate, Nutrition Gillings School of Global Public Health University of North Carolina at Chapel Hill
Talk Outline 1. Background 2. POD Study Methods 3. POD Study Results 4. Conclusions and Future Directions
Background 66.3% of U.S. adults are overweight or obese. Higher risk of developing many chronic diseases. Technology-enhanced approaches to weight loss have begun to emerge. Ogden CL, et. al. JAMA. Apr 2006;295(13):1549-1555. Jee SH, et. al. Yonsei Med J. Aug 31 2005;46(4):449-455. Berkel LA, et. al. J Am Diet Assoc. May 2005;105(5 Suppl 1):S35-43.
Comes from the terms broadcast and ipod. Podcasts are audio files that may be downloaded and listened to on a computer or any portable audio player (MP3 player). What is podcasting?
Who s podcasting? Percentage of internet users who have downloaded a podcast increased from 7% in 2006 to 19% in 2008. Who listens to podcasts by age? 18-29 years old: 27% 30-49 years old: 20% 50+ years old: 23% Madden M. Pew Internet and American Life Report: Podcast Downloading 2008. http://www.pewinternet.org/pdfs/pip_podcast_2008_memo.pdf.
Research Aim To determine whether podcasting weight loss information is an effective way to promote weight loss through a 12-week intervention with adults comparing an existing weight loss podcast to an enhanced, theory-based podcast.
Theories used in the design of enhanced podcast Social Cognitive Theory (SCT) People learn through their own experiences and observations. User Control Theory Control over environment leads to more effective learning. Cognitive Load Theory Decreasing cognitive load leads to better learning. The Elaboration Likelihood Model (ELM) Greater elaboration leads to greater changes in attitudes and behaviors. Eveland WPJ, et. al. Comm Res 2001;28:48-78. Brunken R, et. al. Educ Psych 2003;38:53-61. Paas F, et. al. Educ Psych 2003;38:63-71. Bandura A. Health Educ Behav 2004;31:143-64.
Enhanced, theorybased podcast: introduction audio diary nutrition and exercise information continuing soap opera goals Methods: Groups Randomly assigned to: Control podcast: Best available weight loss podcast Focused on cognitive restructuring: "Think Fit. Be Fit." Example topics included: Goal setting tips Types of exercise
Methods: Participant criteria Overweight men and women (body mass index, 25 40 kg/m 2 ) 12-week intervention, 24 episodes Exclusion criteria unstable medical status, history of an eating disorder, pregnancy, alcohol or drug abuse, tobacco use, mental illness, diabetes mellitus, or an uncontrolled thyroid condition Inclusion criteria: own digital music player (MP3 player) and had access to a body weight scale
Methods: Conceptual Model
Methods: Intervention components and how each targets the theory constructs SCT Construct Intervention Component Expectancies Expectations Self-efficacy Behavioral Capability The Nutrition and Exercise Information of each Podcast emphasized the importance of achieving a healthy weight to increase the value participants place on weight loss. The Audio Diary allowed for a first-hand experience of weight loss and informed participants about what to expect from trying to lose weight. The end of the Podcast included a Goal to Achieve. Participants were encouraged to track their weight, calories, and exercise. The aim of goal achievement was to increase confidence. Knowledge about how to lose weight, exercise, make dietary changes, etc. was presented during the Nutrition and Exercise Information and Soap Opera sections of the podcast.
Methods: Measures Baseline only Height Demographics Baseline and 12 weeks Weight (digital scale accurate to 0.1 kg) Knowledge of weight loss topics (such as how to reduce calorie intake and increase exercise) SCT constructs 12 weeks only Elaboration (the ELM questionnaire slightly modified for this study) User control Cognitive load
Methods: Protocol Introductory meeting Weight, height, questionnaires Book with calorie and fat gram amounts of popular foods Learned how to download podcasts and use the study Web site E-mail reminders for each new podcast Participants who failed to record in their weekly online journal were contacted by e- mail and phone and encouraged to listen to the latest podcasts. Follow-up meeting Weight and questionnaires Learned about other podcast
Demographics Control Group Enhanced Group n Age (years) (mean ± SD) Sex [ N (% )] Male Female Race, ethnicity [ N (% )] Black White Other 37 39.6 (± 12.2) 7 (19) 29 (81) 6 (17) 28 (78) 2 (5) 41 37.7 (± 11.8) 13 (32) 28 (68) 5 (13) 35 (85) 1 (2) *No significant differences between groups at baseline
Results: Changes in weight and BMI 3.5 3-2.9 ± 3.5 kg 2.5 2 1.5 1 0.5 0-0.3 ± 2.1 kg -0.1 ± 0.7 kg/m 2-1.0 ± 1.2 kg/m 2 Control Enhanced P <0.001 for both Weight loss Change in BMI
Results: Knowledge 40 35 30 25 2.4 ± 5.2 5.4 ± 6.5 20 15 10 5 Baseline 12 weeks P <0.05 between groups 0 Control Enhanced 6 questions, 7-point Likert scale, possible score range 6-42
Results: SCT Constructs Self-efficacy 12- weeks Expectancies Baseline 12- weeks Outcome expectations Baseline 12- weeks Control group (n = 36) Baseline 4.36 ± 1.53 4.76 ± 1.59 4.03 ± 1.66-0.33 ± 1.69 6.39 ± 0.87 6.31 ± 1.00-0.08 ± 0.97 5.17 ± 1.80 4.97 ± 2.06-0.19 ± 2.04 Enhanced group (n = 41) 4.80 ± 1.69 0.05 ±1.90 6.27 ± 0.95 6.39 ± 0.89 0.12 ± 0.75 5.20 ± 1.50 5.51 ± 1.63 0.32 ± 1.60 P-value for Between Groups 0.362 0.298 0.226
Results: Elaboration, User Control, Cognitive Load, and Intervention Perception at 12-weeks Elaboration score (possible range 9-63) User Control score (possible score range 10-70) Cognitive Load score (possible score range 2-14 ) Intervention Perception score (possible score range 3-21) Number of podcasts participants reported they listened to during the study (out of 24) Control group (n = 37) 24.7 ± 15.4 40.6 ± 16.0 6.5 ± 4.1 11.2 ± 7.1 16.6 ± 7.5 Enhanced group (n = 41) 41.3 ± 12.3 53.6 ± 12.9 10.6 ± 3.1 17.4 ± 5.1 17.5 ± 8.1 P-value for Between Groups <0.001 <0.001 <0.001 <0.001 0.67
Conclusions Podcasting may be an effective way to deliver health interventions and produce behavior change. Podcasts should be: Theory-based Carefully designed to promote cognitive processing and elaboration of information Future Research Produce long-lasting effects Combine podcasts with other features of an Internet intervention (monitoring, feedback, and support) Other populations?
Acknowledgements Co-Authors at the University of North Carolina at Chapel Hill Marci K. Campbell, PhD, RD Department of Nutrition Deborah F. Tate, PhD Departments of Nutrition and Health Behavior and Health Education Kimberly P. Truesdale, PhD Department of Nutrition J. Michael Bowling, PhD Department of Health Behavior and Health Education Lelia Crosby, BA Lineberger Comprehensive Cancer Center Funding UNC Lineberger Cancer Control Education Program Pre-doctoral Fellowship
Thank you! Brie Turner-McGrievy, MS, RD brie@unc.edu University of North Carolina at Chapel Hill
Additional slides add as needed
Measures Baseline only Height Demographics Baseline and 12 weeks Weight (digital scale accurate to 0.1 kg) Food intake (PrimeScreen Questionnaire) Physical activity (short IPAQ) Knowledge of weight loss topics (such as how to reduce calorie intake and increase exercise) Social cognitive theory constructs (self-efficacy, expectancies, and outcome expectations) 12 weeks only Elaboration (the Elaboration Likelihood Model or ELM questionnaire slightly modified for this study) User control Cognitive load
Results: PrimeScreen Food Categories Vegetables consumption category Baseline 12-weeks Fruit consumption category Baseline 12-weeks High fat foods consumption category Baseline 12-weeks Control group (n = 36) 2.4 ± 0.6 2.6 ± 0.7 0.01 ± 0.4 2.9 ± 0.8 2.7 ± 0.6-0.2 ± 0.7 2.1 ± 0.5 1.9 ± 0.5-0.2 ± 0.4 Enhanced group (n = 41) 2.3 ± 0.7 2.6 ± 0.7 0.4 ± 0.7 2.5 ± 1.0 2.7 ± 0.7 0.2 ± 0.9 2.1 ± 0.5 1.8 ± 0.5-0.3 ± 0.4 P-value for Between Groups <0.05 <0.05 0.14
Results: IPAQ Physical Activity Vigorous activity (days/week) Baseline 12-weeks Moderate activity (days/week) Walking (days/week) Sitting (hours spent/day) Control group (n = 36) 1.8 ± 1.8 1.4 ± 1.6-0.4 ± 1.4 0.3 ± 2.2 0.2 ± 2.2-0.3 ± 8.7 Enhanced group (n = 41) 1.2 ± 1.4 2.1 ± 1.9 0.8 ± 0.9 0.9 ± 2.0 0.7 ± 2.0-0.8 ± 4.8 P-value for Between Groups <0.01 0.22 0.29 0.73
Participant flow chart