Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)


Health and Nutritional Sciences

First Advisor

Kendra Kattelmann


accelerometers, childhood obesity, physical activity, sedentary time, youth


To assess accelerometer-derived physical activity and sedentary time from 0 to 24- months in youth in the iCook 4-H program. The iCook 4-H Program was a 5-state, randomized, control-treatment, family-based childhood obesity prevention intervention promoting cooking, eating and playing together. Youth, 9-10 years old, and their main adult meal preparer, participated in the 12-week program followed by monthly newsletters and bi-yearly booster sessions until 24-months. Physical activity and sedentary time were determined for youth who wore an Actigraph GT3X+ accelerometer for 7 days at 0, 4, 12, and 24-months and met defined accelerometer compliance standards. Mean daily minutes of sedentary time and light, moderate, vigorous, and moderate-to-vigorous physical activity were evaluated during waking hours. Group differences were analyzed from 0 to 24-months using liner mixed models and likelihood ratio tests (p ≤ 0.05) with R data analysis software (R, 3.2.3, Vienna, Austria, 2015). There were no differences in physical activity or sedentary time between treatment and control groups at any time-point. Physical activity at all intensity levels decreased and sedentary time increased within treatment and control groups from 0 to 24-months (p≤0.001). The percent of youth meeting the physical activity guidelines, defined as an average of ≥60 minutes of MVPA per day, decreased from 0-months (30.7% treatment, 41.7% control) to 24-months (8.0% treatment, 0.0% control). Youth responses on the program evaluation survey indicated a trend in differences by group for the amount of time their family spent playing actively together (p=0.08) and how often their heart pumped hard when they were being physically active (p=0.07). The iCook 4-H Program was a multicomponent program following 9-10 year old youth for 24-months that focused on cooking skills, mealtime behavior and conversation, and enhancing physical activity through daily activities. Greater emphasis on developing physical activity skills, improving environmental factors, and increasing physical activity both in school and after school may be needed to prevent the decrease in activity that occurs as children age into adolescence. Interventions may also need to focus on overcoming facilitators for sedentary time and barriers to physical activity. Furthermore, children in the current study demonstrated a more positive outlook on “playing” versus being physically active, which may indicate that future interventions should focus on increasing physical activity through play.

Library of Congress Subject Headings

Exercise for children.

Obesity in children -- Prevention.

Physical fitness for children.

Sedentary behavior.



Includes bibliographical references (pages 53-58)



Number of Pages



South Dakota State University


Copyright © 2016 Emily Jo Hofer