title: The Association between Weight Gain/Restoration and Bone Mineral Density in Adolescents with Anorexia Nervosa: A Systematic Review.
abstract: BACKGROUND
  Reduced bone mineral density (BMD) is one of the most frequent medical complications of anorexia nervosa (AN). The purpose of this paper was to conduct a systematic review of the association between weight gain/restoration and BMD in adolescents with AN.
  
  
  METHODS
  Literature searches, study selection, method, and quality appraisal were performed independently by two authors, and data were collated using a narrative approach.
  
  
  RESULTS
  Of the 1156 articles retrieved, 19 studies met the inclusion criteria, and their analysis revealed four main findings. First, six studies reported that weight gain and restoration are associated with BMD stabilization after one year of follow-up from baseline. Second, seven studies with longer follow-up periods (≈16 months) reported significant improvements in BMD measures. Third, one study showed that normalization of BMD can be achieved after ≈30-month follow-up of normal-weight maintenance. Fourth, another study showed that male adolescents with AN who achieve weight gain but remain underweight may experience further BMD loss, unlike their weight-restored counterparts (BMI ≥ 19 kg/m²), who show a significant increase in BMD and bone mineral accrual rates that double those of healthy male adolescents. The first two findings can be considered robust, as they are supported by strong evidence. The third and fourth findings, however, derive from single studies and therefore require further confirmation.
  
  
  CONCLUSIONS
  The literature supports weight gain as an effective strategy for promoting BMD increase in adolescents with AN. However, this process is slow, and improvements do not become detectable until ≈16-month follow-up.
authors.affiliation: Department of Eating and Weight Disorders, Villa Garda Hospital, Garda 37016, Italy. marwan1979@hotmail.com.
authors.forename: Marwan
authors.initials: M
authors.lastname: El Ghoch
authors.affiliation: Rheumatology Unit, Department of Medicine, University of Verona, Verona 37124, Italy. davide.gatti@univr.it.
authors.forename: Davide
authors.initials: D
authors.lastname: Gatti
authors.affiliation: Department of Eating and Weight Disorders, Villa Garda Hospital, Garda 37016, Italy. si.calugi@gmail.com.
authors.forename: Simona
authors.initials: S
authors.lastname: Calugi
authors.affiliation: Rheumatology Unit, Department of Medicine, University of Verona, Verona 37124, Italy. ombretta.viapiana@univr.it.
authors.forename: Ombretta
authors.initials: O
authors.lastname: Viapiana
authors.affiliation: Department of Radiology, Villa Garda Hospital, Garda 37016, Italy. paola.baz58@gmail.com.
authors.forename: Paola Vittoria
authors.initials: PV
authors.lastname: Bazzani
authors.affiliation: Department of Eating and Weight Disorders, Villa Garda Hospital, Garda 37016, Italy. rdalleg@gmail.com.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Dalle Grave
mesh_terms: D000293:Adolescent; D000856:Anorexia Nervosa / Q000628:therapy*; D015519:Bone Density; D006801:Humans; D013851:Thinness; D015430:Weight Gain
keywords: and bone mineral density; anorexia nervosa; body composition; osteopenia; osteoporosis; weight restoration