title: Does running with or without diet changes reduce fat mass in novice runners? A 1-year prospective study.
abstract: BACKGROUND
  The aim of this study was to explore how average weekly running distance, combined with changes in diet habits and reasons to take up running, influence fat mass.
  
  
  METHODS
  Fat mass was assessed by bioelectrical impedance at baseline and after 12 months in 538 novice runners included in a 1-year observational prospective follow-up study. During follow-up, running distance for each participant was continuously measured by GPS while reasons to take up running and diet changes were assessed trough web-based questionnaires. Loss of fat mass was compared between runners covering an average of 5 km or more per week and those running shorter distances.
  
  
  RESULTS
  Runners who took up running to lose weight and ran over 5 km per week in average over a one-year period combined with a diet change reduced fat mass by -5.58 kg (95% CI: -8.69; -2.46; P<0.001). Compared with subjects also running over 5 km per week but without diet changes, the mean difference in fat mass between groups was 3.81 kg (95% CI: -5.96; -1.66; P<0.001). A difference of -3.55 kg (95% CI: -5.69; -1.41; P<0.001) was found when comparing with those running less than 5 km per week and making changes to their own diet.
  
  
  CONCLUSIONS
  An average running distance of more than 5 km per week in runners who took up running to lose weight combined with a targeted diet change seems effective in reducing fat mass over a one-year period among novice runners. Still, randomized controlled trials are needed to better document the effects of self-selected diet changes.
authors.affiliation: Section of Sport Science, Department of Public Health, Aarhus University, Aarhus, Denmark - roen@sport.au.dk.
authors.forename: Rasmus O
authors.initials: RO
authors.lastname: Nielsen
authors.forename: Solvej
authors.initials: S
authors.lastname: Videbaek
authors.forename: Mette
authors.initials: M
authors.lastname: Hansen
authors.forename: Erik T
authors.initials: ET
authors.lastname: Parner
authors.forename: Sten
authors.initials: S
authors.lastname: Rasmussen
authors.forename: Henning
authors.initials: H
authors.lastname: Langberg
mesh_terms: D050154:Adiposity / Q000502:physiology*; D000328:Adult; D001835:Body Weight; D004032:Diet / Q000523:psychology; D017097:Electric Impedance; D005247:Feeding Behavior / Q000502:physiology* / Q000523:psychology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009042:Motivation; D005082:Physical Exertion / Q000502:physiology*; D011446:Prospective Studies; D012420:Running / Q000502:physiology* / Q000523:psychology; D011795:Surveys and Questionnaires