title: [DO WEIGHT LOSS INCREASE LIFE EXPECTANCY?: SYSTEMATIC REVIEW].
abstract: BACKGROUND
  prospective trials that assess the effect of weight loss on all-cause mortality have shown controversial results. We conducted a systematic review of prospective studies, with a follow up ≥10y, assessing the association of weight loss and weight cycling with all cause- mortality.
  
  
  METHODS
  we searched Pubmed of prospective studies with a follow up of ≥10y, published from January 1st 2004 to December 31th 2014.
  
  
  RESULTS
  nine studies met the inclusion criteria. Five studies assessed the association between weight loss and mortality, two of the studies examined weight cycling and mortality, and two other weight loss and weight cycling with mortality. Weight loss increased all-cause mortality in those that assessed weight loss and mortality. In the two studies evaluating the association between weight cycling and mortality, weight cycling made no difference on mortality. In the two studies assessing weight loss and weight cycling, results showed weight cycling increased mortality in both of them, and weight loss increased mortality in one study.
  
  
  CONCLUSIONS
  six out of seven (≥10 y of follow up) prospective studies showed that weight loss was associated with increased mortality; the results from studies assessing weight cycling were inconsistent. None of the studies found evidence showing that weight loss improved life expectancy.
authors.affiliation: Universidad Autónoma de Baja California. Facultad de Medicina y Psicología, Mexico.. dra.karenlizarraga@gmail.com.
authors.forename: Karen
authors.initials: K
authors.lastname: Lizárraga Hernández
authors.affiliation: Universidad Autónoma de Baja California. Facultad de Medicina y Psicología, Mexico.. montserrat.bacardi@uabc.edu.mx.
authors.forename: Montserrat
authors.initials: M
authors.lastname: Bacardí Gascón
authors.affiliation: Universidad Autónoma de Baja California. Facultad de Medicina y Psicología, Mexico.. arturojimenezc@yahoo.com.
authors.forename: Arturo
authors.initials: A
authors.lastname: Jiménez Cruz
mesh_terms: D006801:Humans; D008017:Life Expectancy; D009026:Mortality; D009765:Obesity / Q000401:mortality; D015431:Weight Loss / Q000502:physiology*