title: How can GPS technology help us better understand exposure to the food environment? A systematic review.
abstract: OBJECTIVE
  Global Positioning Systems (GPS) are increasingly being used to objectively assess movement patterns of people related to health behaviours. However research detailing their application to the food environment is scarce. This systematic review examines the application of GPS in studies of exposure to food environments and their potential influences on health.
  
  
  METHODS
  Based on an initial scoping exercise, published articles to be included in the systematic review were identified from four electronic databases and reference lists and were appraised and analysed, the final cut-off date for inclusion being January 2015. Included studies used GPS to identify location of individuals in relation to food outlets and link that to health or diet outcomes. They were appraised against a set of quality criteria.
  
  
  RESULTS
  Six studies met the inclusion criteria, which were appraised to be of moderate quality. Newer studies had a higher quality score. Associations between observed mobility patterns in the food environment and diet related outcomes were equivocal. Findings agreed that traditional food exposure measures overestimate the importance of the home food environment.
  
  
  CONCLUSIONS
  The use of GPS to measure exposure to the food environment is still in its infancy yet holds much potential. There are considerable variations and challenges in developing and standardising the methods used to assess exposure.
authors.affiliation: School of Environmental Sciences, University of East Anglia, Norwich, Norfolk NR4 7TJ, UK; Centre for Diet and Physical Activity Research, Box 296, Institute of Public Health, Forvie Site, Robinson Way, Cambridge CB2 0SR, UK; School of Public Health, Imperial College London, St Mary׳s Campus, Medical School Building, Office G39, Norfolk Place, W2 1PG London, UK.
authors.forename: Andreea
authors.initials: A
authors.lastname: Cetateanu
authors.affiliation: Norwich Medical School, University of East Anglia, Norwich, Norfolk NR4 7TJ, UK; Centre for Diet and Physical Activity Research, Box 296, Institute of Public Health, Forvie Site, Robinson Way, Cambridge CB2 0SR, UK.
authors.forename: Andy
authors.initials: A
authors.lastname: Jones
keywords: Food environments; Food exposure; Geographic information system; Global positioning systems; Systematic review