title: Dietary sodium intake and overweight and obesity in children and adults: a protocol for a systematic review and meta-analysis.
abstract: BACKGROUND
  Overweight and obesity in children and adults is a major public health concern. Emerging evidence suggests dietary sodium intake may be associated with obesity. This systematic review and meta-analysis will aim to (i) assess the relation between dietary sodium intake and measures of adiposity in children and adults and (ii) examine the relation between sodium intake and sugar-sweetened beverage (SSB) consumption, which is a known risk factor for obesity.
  
  
  METHODS
  An electronic search will be conducted using Medline Complete, CINAHL, Scopus, Embase and Cochrane central register of controlled trials (CENTRAL). The search strategy will identify published peer-reviewed articles that report on dietary sodium and either a marker of adiposity or SSB consumption. Only human studies (ages >1 year) in English will be included, and no limits will be placed on publication date. No restrictions will be placed on the method of sodium intake assessment. Cross-sectional, prospective studies, and randomised controlled trials with a duration of ≥ 3 months will be included. Studies with participants with renal disease, cancer, type 1 diabetes or heart failure or who are pregnant will be excluded. To assess the quality of studies, the Cochrane's Collaboration tool for assessing risk of bias in randomised trials will be used for randomised controlled trials (RCTs), and the modified Newcastle-Ottawa Scale will be used for cross-sectional and prospective studies. Meta-analysis will be used to assess the relation of sodium intake with two primary outcomes: (i) BMI and body weight in adults and BMI z-score in children and (ii) weight category (i.e. healthy weight vs. overweight/obese). For any outcomes in which meta-analysis is not possible, we will present data as a systematic review. Findings will be grouped and reported separately for children and adolescents (ages 1-17 years) and adults (ages >18 years).
  
  
  CONCLUSIONS
  This review and meta-analysis will provide insight into the relation between dietary sodium intake and overweight and obesity. This information can be used to inform public health policies which target population sodium consumption.
  
  
  BACKGROUND
  Prospero CRD42015016440.
authors.affiliation: Centre for Physical Activity and Nutrition Research, School of Exercise and Nutrition Sciences, Deakin University, 221 Burwood Highway, Burwood, Victoria, 3125, Australia. carley.grimes@deakin.edu.au.
authors.forename: Carley A
authors.initials: CA
authors.lastname: Grimes
authors.affiliation: Centre for Advanced Sensory Science, School of Exercise and Nutrition Sciences, Deakin University, 221 Burwood Highway, Burwood, Victoria, 3125, Australia. d.bolhuis@deakin.edu.au.
authors.forename: Dieuwerke P
authors.initials: DP
authors.lastname: Bolhuis
authors.affiliation: Centre for Environmental and Preventative Medicine, Wolfson Institute of Preventative Medicine, Queen Mary University of London, Charterhouse Square, London, EC1M 6BQ, UK. f.he@qmul.ac.uk.
authors.forename: Feng J
authors.initials: FJ
authors.lastname: He
authors.affiliation: Centre for Physical Activity and Nutrition Research, School of Exercise and Nutrition Sciences, Deakin University, 75 Pigdons Road, Waurn Ponds Campus, Geelong, Victoria, 3216, Australia. caryl.nowson@deakin.edu.au.
authors.forename: Caryl A
authors.initials: CA
authors.lastname: Nowson
mesh_terms: D000328:Adult; D002648:Child; D006801:Humans; D009765:Obesity / Q000453:epidemiology; D050177:Overweight / Q000453:epidemiology*; D012982:Sodium, Dietary / Q000008:administration & dosage*; D000078202:Systematic Reviews as Topic; D015201:Meta-Analysis as Topic
chemical_list: D012982:Sodium, Dietary