Objective: To investigate the extent to which changes in physical activity predict changes in abdominal fat in women over an 18-month period, while statistically controlling the effects of possible confounders, such as age, total body fat percent, and energy intake. Design: A prospective cohort design over 18 months. There was no intervention or treatment. Changes in objectively-measured physical activity were used to predict changes in abdominal fat over the study period. Subjects: 110 healthy, middle-aged women (mean: 41.3±3.3 yrs), primarily Caucasian, educated, and married. Measurements: An objective measure of physical activity (ACT) using CSA accelerometers, worn continuously for 7 consecutive days at baseline and again at follow-up. Total body fat and abdominal fat percent were assessed by dual energy x-ray absorptiometry (DEXA). Energy intake was estimated using 7-day, weighed food records for the days in which subjects wore accelerometers. Results: No significant change between baseline and follow-up means for abdominal fat, physical activity, or energy intake over the study period. Moreover, change in physical activity was not a significant predictor of change in abdominal fat, with or without statistical control of confounders. Change in energy intake was a predictor of abdominal fat (P=0.0688), and this association was strengthened after adjusting for age, baseline total body fat, and changes in physical activity. Conclusions: Apparently, when measured using accelerometers, changes in physical activity are not predictive of changes in abdominal fat over an 18-month period. However, changes in energy intake seem to predict changes in abdominal fat. Evidently, increases and decreases in abdominal fat are more a function of energy intake than physical activity in middle-aged women.
","abstract_html":"<p>Objective: To investigate the extent to which changes in physical activity predict changes in abdominal fat in women over an 18-month period, while statistically controlling the effects of possible confounders, such as age, total body fat percent, and energy intake. Design: A prospective cohort design over 18 months. There was no intervention or treatment. Changes in objectively-measured physical activity were used to predict changes in abdominal fat over the study period. Subjects: 110 healthy, middle-aged women (mean: 41.3±3.3 yrs), primarily Caucasian, educated, and married. Measurements: An objective measure of physical activity (ACT) using CSA accelerometers, worn continuously for 7 consecutive days at baseline and again at follow-up. Total body fat and abdominal fat percent were assessed by dual energy x-ray absorptiometry (DEXA). Energy intake was estimated using 7-day, weighed food records for the days in which subjects wore accelerometers. Results: No significant change between baseline and follow-up means for abdominal fat, physical activity, or energy intake over the study period. Moreover, change in physical activity was not a significant predictor of change in abdominal fat, with or without statistical control of confounders. Change in energy intake was a predictor of abdominal fat (P=0.0688), and this association was strengthened after adjusting for age, baseline total body fat, and changes in physical activity. Conclusions: Apparently, when measured using accelerometers, changes in physical activity are not predictive of changes in abdominal fat over an 18-month period. However, changes in energy intake seem to predict changes in abdominal fat. Evidently, increases and decreases in abdominal fat are more a function of energy intake than physical activity in middle-aged women.</p>","abstract_has_math":false,"creators":["Davidson, Lance Eric"],"institution":"Brigham Young University - Provo","degree_name":"MS","degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":null,"date_issued":"","date_published":null,"updated_at":"2026-07-24T01:28:54Z","subjects":["abdominal fat","physical activity","energy intake","DEXA","CSA accelerometer","Exercise Science"],"languages":["English"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://scholarsarchive.byu.edu/etd/1140","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Davidson, Lance Eric"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2003-03-12T08:00:00Z"]},{"key":"dc:publisher","label":"Institution","values":["Brigham Young University - Provo"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["MS"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["abdominal fat","physical activity","energy intake","DEXA","CSA accelerometer","Exercise Science"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["English"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://scholarsarchive.byu.edu/etd/1140","https://scholarsarchive.byu.edu/context/etd/article/2139/viewcontent/ETD_CISOPTR_21.pdf"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Life Sciences; Exercise Sciences","0;Physical Education
"]},{"key":"dc:description.abstract","label":"Abstract","values":["Objective: To investigate the extent to which changes in physical activity predict changes in abdominal fat in women over an 18-month period, while statistically controlling the effects of possible confounders, such as age, total body fat percent, and energy intake. Design: A prospective cohort design over 18 months. There was no intervention or treatment. Changes in objectively-measured physical activity were used to predict changes in abdominal fat over the study period. Subjects: 110 healthy, middle-aged women (mean: 41.3±3.3 yrs), primarily Caucasian, educated, and married. Measurements: An objective measure of physical activity (ACT) using CSA accelerometers, worn continuously for 7 consecutive days at baseline and again at follow-up. Total body fat and abdominal fat percent were assessed by dual energy x-ray absorptiometry (DEXA). Energy intake was estimated using 7-day, weighed food records for the days in which subjects wore accelerometers. Results: No significant change between baseline and follow-up means for abdominal fat, physical activity, or energy intake over the study period. Moreover, change in physical activity was not a significant predictor of change in abdominal fat, with or without statistical control of confounders. Change in energy intake was a predictor of abdominal fat (P=0.0688), and this association was strengthened after adjusting for age, baseline total body fat, and changes in physical activity. Conclusions: Apparently, when measured using accelerometers, changes in physical activity are not predictive of changes in abdominal fat over an 18-month period. However, changes in energy intake seem to predict changes in abdominal fat. Evidently, increases and decreases in abdominal fat are more a function of energy intake than physical activity in middle-aged women.
"]},{"key":"dc:format","label":"Dc Format","values":["application:pdf"]},{"key":"dc:source","label":"Dc Source","values":["Brigham Young University - Provo"]},{"key":"dc:title","label":"Title","values":["Physical Activity and Changes in Abdominal Fat Over 18 Months: A Prospective Study of Middle-Aged Women"]}]}],"canonical_facts":{"dc:creator":["Davidson, Lance Eric"],"dc:date":["2003-03-12T08:00:00Z"],"dc:description":["Life Sciences; Exercise Sciences","0;Physical Education
"],"dc:description.abstract":["Objective: To investigate the extent to which changes in physical activity predict changes in abdominal fat in women over an 18-month period, while statistically controlling the effects of possible confounders, such as age, total body fat percent, and energy intake. Design: A prospective cohort design over 18 months. There was no intervention or treatment. Changes in objectively-measured physical activity were used to predict changes in abdominal fat over the study period. Subjects: 110 healthy, middle-aged women (mean: 41.3±3.3 yrs), primarily Caucasian, educated, and married. Measurements: An objective measure of physical activity (ACT) using CSA accelerometers, worn continuously for 7 consecutive days at baseline and again at follow-up. Total body fat and abdominal fat percent were assessed by dual energy x-ray absorptiometry (DEXA). Energy intake was estimated using 7-day, weighed food records for the days in which subjects wore accelerometers. Results: No significant change between baseline and follow-up means for abdominal fat, physical activity, or energy intake over the study period. Moreover, change in physical activity was not a significant predictor of change in abdominal fat, with or without statistical control of confounders. Change in energy intake was a predictor of abdominal fat (P=0.0688), and this association was strengthened after adjusting for age, baseline total body fat, and changes in physical activity. Conclusions: Apparently, when measured using accelerometers, changes in physical activity are not predictive of changes in abdominal fat over an 18-month period. However, changes in energy intake seem to predict changes in abdominal fat. Evidently, increases and decreases in abdominal fat are more a function of energy intake than physical activity in middle-aged women.
"],"dc:format":["application:pdf"],"dc:identifier":["https://scholarsarchive.byu.edu/etd/1140","https://scholarsarchive.byu.edu/context/etd/article/2139/viewcontent/ETD_CISOPTR_21.pdf"],"dc:language":["English"],"dc:publisher":["Brigham Young University - Provo"],"dc:source":["Brigham Young University - Provo"],"dc:subject":["abdominal fat","physical activity","energy intake","DEXA","CSA accelerometer","Exercise Science"],"dc:title":["Physical Activity and Changes in Abdominal Fat Over 18 Months: A Prospective Study of Middle-Aged Women"],"dc:type":["Thesis"],"thesis:degree_name":["MS"]},"updated_at":"2026-07-24T01:28:54Z"}