Background: Overviews of systematic reviews (SR) are increasingly being used to signpost clinicians, guideline developers and policy makers to the best-available evidence. However, the role of overviews in identifying areas where research effort can be reduced or where further research is unnecessary has not been fully explored. Objectives: To identify areas of research waste and evidence gaps using data from a recent overview, which synthesised population-level interventions aimed at improving the health, happiness and wellbeing of adolescents transitioning into adulthood. Methods: A rapid overview. We systematically searched 11 electronic databases for SR published in English between Jan 2005 - March 2016. Two reviewers independently applied inclusion criteria and assessed methodological quality using the ROBIS tool. Data relating to review aim, participants, study design, interventions, setting and outcomes were extracted from SR judged to have low or unclear risk of bias (ROB). Interventions were mapped using the US National Prevention Strategy framework. Reviews synthesising the same or similar evidence were identified and overlap between SR addressing similar interventions was explored. Interventions where there were no reviews were identified. Results: 35310 titles screened; 566 full papers considered; 256 reviews included. 150/256 reviews were judged as low or unclear ROB. Reviews were allocated to 9 themes including mental health and wellbeing; tobacco-free living; preventing drug abuse and excessive drinking; sexual and reproductive health; violence and abuse-free living; active living; healthy eating; obesity and general health. Multiple reviews, addressing the same research question, were identified particularly in topics with a physical health focus (e.g. obesity and active living). No reviews addressed the original research question. Other relevant evidence gaps included eating disorders, employment, gang violence and resilience. Conclusions: Multiple overlapping reviews are wasteful. Overviews have an emerging role in identifying and quantifying research volume, highlighting research waste and areas where further research is (or is not) required.