title: Role of Melatonin in Body Weight: A Systematic Review and Meta-Analysis.
abstract: Some trials on animals and human claim that melatonin can influence body weight. So we conducted a systematic review of controlled trials of melatonin effects on weight of human subjects.
  
  
  
  First we performed a systematic and comprehensive search in June 2015 on MEDLINE/PubMed, Scopus, Google scholar, hand searching in key journals, the list of references of selected articles and gray literature.
  
  
  
  We included 7 clinical trials with a total of 244 patients. All studies were parallel clinical trials conducted at the clinic. Evaluating standardized mean difference (SMD) using Cohen's method shows that none of the included studies have found a strong and significant effect of melatonin on body weight. However, some have reported decreasing or increasing effect of melatonin on body weight. We pooled SMDs using random effects (DerSimonian and Laird). Pooled SMD was still not significant SMD (95% CI) = 0.09(-0.17-0.34), with lack of heterogeneity I2=0.0%, p=0.66.
  
  
  
  We concluded that once the standard treatment had increasing effect on body weight, melatonin could be able to slightly diminish this effect and vice versa. Subgroup analysis showed that melatonin was more effective in child and adolescents. According to the results hypothesis of the buffering role of melatonin on body weight fluctuations can be proposed.
authors.affiliation: Psychiatry & Psychology Research Center, Roozbeh Hospital, Tehran University of Medical Sciences, Tehran. Iran.
authors.forename: Seyed-Ali
authors.initials: SA
authors.lastname: Mostafavi
authors.affiliation: Psychiatry & Psychology Research Center, Roozbeh Hospital, Tehran University of Medical Sciences, Tehran. Iran.
authors.forename: Shahin
authors.initials: S
authors.lastname: Akhondzadeh
authors.affiliation: Psychiatry & Psychology Research Center, Roozbeh Hospital, Tehran University of Medical Sciences, Tehran. Iran.
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Mohammadi
authors.affiliation: Department of Health Sciences Education Development, School of Public Health, Tehran University of Medical Sciences, Tehran. Iran.
authors.forename: Abbas-Ali
authors.initials: AA
authors.lastname: Keshtkar
authors.affiliation: Department of Clinical Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran. Iran.
authors.forename: Saeed
authors.initials: S
authors.lastname: Hosseini
authors.affiliation: Department of Biostatistics and Epidemiology, School of Public health, Tehran University of Medical Sciences, Tehran. Iran.
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Eshraghian
authors.affiliation: Department of Nutrition, School of Public Health, Iran University of Medical Sciences, Tehran. Iran.
authors.forename: Taranom Ahmadi
authors.initials: TA
authors.lastname: Motlagh
authors.affiliation: Department of Nutrition, School of Public Health, Iran University of Medical Sciences, Tehran. Iran.
authors.forename: Rooya
authors.initials: R
authors.lastname: Alipour
authors.affiliation: Head of Clinical Nutrition Department, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran. Iran.
authors.forename: Seyed Ali
authors.initials: SA
authors.lastname: Keshavarz
mesh_terms: D001835:Body Weight / Q000187:drug effects* / Q000502:physiology*; D006801:Humans; D008550:Melatonin / Q000494:pharmacology* / Q000502:physiology*; D016032:Randomized Controlled Trials as Topic / Q000379:methods
chemical_list: D008550:Melatonin
keywords: Body weight; hypothesis; melatonin; meta-analysis; metabolic homeostasis; parallel clinical trials