The resumption of menses (ROM) is an important outcome in anorexia nervosa treatment and is considered as a sign of recovery. Identification of relevant factors in its prediction is important in clinical practice. Therefore we aimed to conduct a systematic review and exploratory meta-analysis of the association between total body fat percentage (%BF) and ROM after weight restoration in adolescents and young adults with anorexia nervosa. The study was conducted by adhering to Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. Data were collated using meta-analysis and a narrative approach. Of the 604 articles retrieved, only seven studies comprising a total of 366 adolescent and young adult females with anorexia nervosa met the inclusion criteria and were reviewed, and preliminary results revealed three main findings. Firstly, patients who resumed their menstrual cycle had a significantly higher mean %BF when compared to those who did not, an overall effect confirmed by the meta-analysis (SMD: 3.74, 95% CI: 2.26-5.22). Secondly, %BF was found to be an independent predictor of the ROM in this population and an increase of only one unit of %BF can increase the odds of menstruation by ≈15-20%. Thirdly, despite the paucity of data, a cut-off point of %BF≈21was suggested as the minimum needed for ROM. In conclusion, a higher %BF seems to be associated with the ROM in weight-restored adolescent and young adult females with anorexia nervosa. Its assessment is important in a clinical setting, especially after complete weight restoration. The PROSPERO Registry - A systematic review and meta-analysis of the factors associated with the resumption of the menstrual cycle in females with anorexia nervosa after weight restoration (CRD42019111841).