Does running with or without diet changes reduce fat mass in novice runners? A 1-year prospective study

J Sports Med Phys Fitness. 2016 Jan-Feb;56(1-2):105-13. Epub 2015 Mar 13.


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.

Publication types

  • Observational Study

MeSH terms

  • Adiposity / physiology*
  • Adult
  • Body Weight
  • Diet* / psychology
  • Electric Impedance
  • Feeding Behavior / physiology*
  • Feeding Behavior / psychology
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Motivation
  • Physical Exertion / physiology*
  • Prospective Studies
  • Running / physiology*
  • Running / psychology
  • Surveys and Questionnaires