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Adherence to the Physical Activity Goal among Adults with Overweight or Obesity in a mHealth Weight Loss Trial

Bizhanova, Zhadyra (2022) Adherence to the Physical Activity Goal among Adults with Overweight or Obesity in a mHealth Weight Loss Trial. Doctoral Dissertation, University of Pittsburgh. (Unpublished)

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Background: The use of wearable activity trackers can improve engagement in physical activity (PA). There is limited evidence on the long-term use of wearable activity trackers for promoting PA guidelines in adults with overweight or obesity.
Objectives: This dissertation aimed to 1) identify baseline and short-term response predictors of adherence to the study-defined PA goal, 2) determine distinct trajectories of adherence to weekly PA goals and examine their association with baseline and first week response predictors and percent weight change at 12 months, and 3) explore associations between the percent of adherence to the PA goal and changes in percent body fat and sex-specific waist circumference (WC) in adults who are overweight or obese and participated in a mobile health (mHealth) weight loss intervention for 12 months.
Methods: A secondary analysis was conducted of PA data collected using Fitbit Charge 2™ trackers from the SMARTER weight loss trial examining the efficacy of two interventions: self-monitoring of diet, PA and weight with daily tailored feedback (n=251) or self-monitoring alone (n=251).
Results: The sample (N=502) was mostly female (80%), White (83%) with a mean age of 45±14.4 years and body mass index of 33.7±4.0 kg/m2. Machine learning methods identified higher PA goal adherence for the first week, greater PA intervention engagement, greater weight loss by the first month, older age, being male, and being not married/partnered as predictors of higher PA goal adherence over 52 weeks. Group-based trajectory modeling revealed 5 distinct trajectories of percent of adherence to weekly PA goals: extremely low adherence with linear decline (n=119, 23.7%), stable low adherence (n=161, 31.5%), initially adherent with cubic decline (n=114, 23%), adherent with cubic increase (n=79, 15.9%) and highly adherent with quadratic increase (n=29, 5.8%). Higher trajectories of adherence to weekly PA goals were associated with greater weight loss at 12 months. Lastly, greater PA goal adherence was associated with decreases in percent body fat and male WC.
Conclusion: These findings have significant implications for public health given the high prevalence of obesity and sedentary behavior, and the comorbidities associated with these conditions that lead to rising healthcare costs and premature mortality.


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Item Type: University of Pittsburgh ETD
Status: Unpublished
CreatorsEmailPitt UsernameORCID
Bizhanova, Zhadyrazhb10@pitt.eduZHB100000-0003-0820-019X
ETD Committee:
TitleMemberEmail AddressPitt UsernameORCID
Committee ChairBurke, Loralbu100@pitt.edulbu100
Committee CoChairSereika, Susanssereika@pitt.edussereika
Committee MemberBrooks, Mariambrooks@pitt.edumbrooks
Committee MemberRockette-Wagner, Bonnybjr26@pitt.edubjr26
Committee MemberKariuki, Jacobkigok@pitt.edukigok
Date: 30 August 2022
Date Type: Publication
Defense Date: 27 July 2022
Approval Date: 30 August 2022
Access Restriction: 2 year -- Restrict access to University of Pittsburgh for a period of 2 years.
Number of Pages: 126
Institution: University of Pittsburgh
Schools and Programs: School of Public Health > Epidemiology
Degree: PhD - Doctor of Philosophy
Thesis Type: Doctoral Dissertation
Refereed: Yes
Uncontrolled Keywords: Physical Activity; Weight Loss; Mobile Health; Fitbit Trackers; Obesity;
Date Deposited: 30 Aug 2022 13:33
Last Modified: 30 Aug 2022 13:33


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