Browsing by Subject "Behavior Change"

Now showing 1 - 3 of 3
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    Characterizing Behavior Change Interventions to Improve Pediatric Obesity Prevention Research
    (2016-09) JaKa, Meghan
    Behavior change interventions to prevent pediatric obesity are critical. The efficacy of these interventions has been modest and reasons for the less-than-desired results are unclear. This dissertation includes three manuscripts aimed at characterizing and identifying effective components within the ‘black box’ of pediatric obesity prevention interventions. The first manuscript assesses the reliability of a standardized method for coding characteristics of an intervention delivered to parents of 5- to 10-year-old children at risk for becoming overweight or obese. The second manuscript evaluates if parents, when given choice in a pediatric obesity prevention intervention, spend time discussing the weight-related behaviors most relevant to their child’s obesity risk. The purpose of the third manuscript is to identify relationships between specific intervention characteristics and study outcomes (i.e., change in child weight-related behaviors and BMI percentile). By using reliable, standardized methods to identify effective intervention characteristics, this dissertation paves the way for future researchers to design more focused interventions, ultimately leading to successful prevention of pediatric obesity.
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    Examining Physical Activity Intensity and Continuation in Weight Loss Seeking and Non-Weight Loss Seeking Adult Samples
    (2017-08) Gavin, Kara
    This dissertation consists of three investigations covering topics on physical activity achievement and continuation and its relationship with body weight in two intervention samples. The data for the first two papers come from the Tracking Study weight loss intervention trial, while data for the third paper come from the Stand & Move at Work group-randomized worksite LPA intervention trial. Manuscript 1 examined the relationship between the occurrence of life events, MVPA achievement and weight loss maintenance success following a lifestyle weight loss intervention using a 4-way mediation and moderation decomposition analysis. Findings suggested that the effects of life events and MVPA on weight loss maintenance should be considered as separate effects when considering weight loss maintenance and designing interventions to prevent weight re-gain. Manuscript 2 utilized behavior-tracking logs during a weight loss intervention to identify individuals who may show signs of behavioral disengagement and increased weight. General Estimating Equation (GEE) modeling was used to examine the association between physical activity self-monitoring characteristics and reported MVPA participation and weight measured at 12-month and 24-month follow-up. Results showed various self-monitoring characteristics were associated with MVPA participation and weight at 12- and 24-month time points, suggesting that behavior-tracking characteristics should be used to monitor intervention engagement. Manuscript 3 explored differences in LPA participation by BMI category. Hierarchical models examined the association of BMI category with baseline work time LPA participation, total daily LPA participation, and work time LPA participation over time from baseline to 3 months. At baseline there were no statistical differences in work time LPA participation across BMI categories. At three months, participants with BMI in normal and overweight categories participated in work time LPA longer than participants with BMI in the obese category. The findings of this dissertation inform future intervention design and measurement implications for behavioral science and epidemiology.
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    What sustains behavioral changes? A dynamical systems approach to improving theories of change in physical exercise
    (2019-08) Lenne, Richard
    Health behaviors, such as physical exercise, are associated with chronic diseases that top the list of all-cause mortality. Yet, the most healthful lifestyle changes people can (and often want to) make, also tend to be the most challenging to sustain. This dissertation explores how modeling behavior as a dynamical system could improve understanding of psychological processes that sustain behavioral changes. I focus on two classes of processes—motivational and habitual—that may be most pertinent to sustaining changes in physical exercise. A model based on prior theorizing is constructed and simulated (Study 1), and observational data are analyzed (Study 2). Intensive longitudinal data are collected from healthy US-based Fitbit users who recently initiated an increase in exercise. Participants are prospectively observed for two months during which measures of motivation and habit are assessed three days per week, and exercise-as-usual is passively tracked via Fitbit. I find that within-person increases in the automaticity with which exercise is performed in a given week is associated with increases in time spent exercising. Furthermore, differences in the trajectory of automaticity and satisfaction with exercise over time may differentiate those who successfully maintain increases in exercise and those who do not. Results are placed in the context of contemporary theories of behavior change maintenance and suggestions for improvement are forwarded.