title: Mediating effects of dietary intake on associations of TV viewing, body mass index and metabolic syndrome in adolescents.
abstract: Evidence suggests that TV viewing is associated with body mass index (BMI) and metabolic syndrome (MetS) in adolescents. However, it is unclear whether dietary intake mediates these relationships.
  
  
  
  A cross-sectional analysis was conducted in adolescents (12-19 years) participating in the 2003-2006 United States National Health and Nutrition Examination Survey. BMIzscores (zBMI) (n= 3,161) and MetS (n= 1,379) were calculated using age- and sex-specific criteria for adolescents. TV viewing (h/day) was measured via a self-reported questionnaire, and dietary intake was assessed using two 24-h recalls. Using the MacKinnon method, a series of mediation analyses were conducted examining five dietary mediators (total energy intake, fruit and vegetable intake, discretionary snacks, sugar-sweetened beverages and diet quality) of the relationships between TV viewing and zBMI and MetS.
  
  
  
  Small positive relationships were observed between TV viewing and zBMI (β = 0.99,p< 0.001) and TV viewing and MetS (OR = 1.18,p= 0.046). No dietary element appeared to mediate the relationship between TV viewing and zBMI. However, sugar-sweetened beverage consumption and fruit and vegetable intake partially mediated the relationship between TV viewing and MetS, explaining 8.7% and 4.1% of the relationship, respectively.
  
  
  
  These findings highlight the complexity of the relationships between TV viewing, dietary intake and cardiometabolic health outcomes, and that TV viewing should remain a target for interventions.
authors.affiliation: Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences Deakin University Geelong Australia.
authors.forename: E A
authors.initials: EA
authors.lastname: Fletcher
authors.affiliation: Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences Deakin University Geelong Australia.
authors.forename: S A
authors.initials: SA
authors.lastname: McNaughton
authors.affiliation: Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences Deakin University Geelong Australia.
authors.forename: K E
authors.initials: KE
authors.lastname: Lacy
authors.affiliation: Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences Deakin University Geelong Australia; Baker IDI Heart and Diabetes Institute Melbourne Victoria Australia; School of Public Health and Preventive Medicine Monash University Melbourne Australia; School of Public Health The University of Queensland Brisbane Australia; Department of Medicine Monash University Melbourne Australia; School of Sport Science, Exercise and Health The University of Western Australia Perth Australia; Mary MacKillop Institute for Health Research Australian Catholic University Melbourne Australia.
authors.forename: D W
authors.initials: DW
authors.lastname: Dunstan
authors.affiliation: Faculty of Physical Education and Recreation University of Alberta Edmonton Alberta Canada.
authors.forename: V
authors.initials: V
authors.lastname: Carson
authors.affiliation: Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences Deakin University Geelong Australia.
authors.forename: J
authors.initials: J
authors.lastname: Salmon
keywords: BMI; dietary intake; metabolic syndrome; television