title: Longitudinal associations between body mass index, physical activity, and healthy dietary behaviors in adults: A parallel latent growth curve modeling approach.
abstract: BACKGROUND
  Physical activity (PA) and healthy dietary behaviors (HDB) are two well-documented lifestyle factors influencing body mass index (BMI). This study examined 7-year longitudinal associations between changes in PA, HDB, and BMI among adults using a parallel latent growth curve modeling (LGCM).
  
  
  METHODS
  We used prospective cohort data collected by a private company (SimplyWell LLC, Omaha, NE, USA) implementing a workplace health screening program. Data from a total of 2,579 adults who provided valid BMI, PA, and HDB information for at least 5 out of 7 follow-up years from the time they entered the program were analyzed. PA and HDB were subjectively measured during an annual online health survey. Height and weight measured during an annual onsite health screening were used to calculate BMI (kg·m2). The parallel LGCMs stratified by gender and baseline weight status (normal: BMI<25, overweight BMI 25-29.9, and obese: BMI>30) were fitted to examine the longitudinal associations of changes in PA and HDB with change in BMI over years.
  
  
  RESULTS
  On average, BMI gradually increased over years, at rates ranging from 0.06 to 0.20 kg·m2·year, with larger increases observed among those of normal baseline weight status across genders. The increases in PA and HDB were independently associated with a smaller increase in BMI for obese males (b = -1.70 and -1.98, respectively), and overweight females (b = -1.85 and -2.46, respectively) and obese females (b = -2.78 and -3.08, respectively). However, no significant associations of baseline PA and HDB with changes in BMI were observed.
  
  
  CONCLUSIONS
  Our study suggests that gradual increases in PA and HDB are independently associated with smaller increases in BMI in overweight and obese adults, but not in normal weight individuals. Further study is warranted to address factors that check increases in BMI in normal weight adults.
authors.affiliation: Department of Kinesiology and Sport Management, Texas Tech University, Lubbock, Texas, United States of America.
authors.forename: Youngdeok
authors.initials: Y
authors.lastname: Kim
authors.affiliation: School of Health, Physical Education and Recreation, University of Nebraska Omaha, Omaha, Nebraska, United States of America.
authors.forename: Jung-Min
authors.initials: JM
authors.lastname: Lee
authors.affiliation: College of Public Health, University of Nebraska Medical Center, Omaha, Nebraska, United States of America.
authors.forename: Jungyoon
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Kinesiology and Sport Management, Texas Tech University, Lubbock, Texas, United States of America.
authors.forename: Emily
authors.initials: E
authors.lastname: Dhurandhar
authors.affiliation: Department of Environmental, Occupational and Geospatial Health Sciences, City University of New York, New York, New York, United States of America.
authors.forename: Ghada
authors.initials: G
authors.lastname: Soliman
authors.affiliation: College of Public Health, University of Nebraska Medical Center, Omaha, Nebraska, United States of America.
authors.forename: Nizar K
authors.initials: NK
authors.lastname: Wehbi
authors.affiliation: Nebraska Medicine, Omaha, Nebraska, United States of America.
authors.forename: James
authors.initials: J
authors.lastname: Canedy
mesh_terms: D000328:Adult; D015992:Body Mass Index; D004032:Diet; D015444:Exercise; D006293:Health Promotion; D006801:Humans; D008137:Longitudinal Studies; D008875:Middle Aged; D008962:Models, Theoretical; D011446:Prospective Studies