The prevalence of metabolically healthy obesity: a systematic review and critical evaluation of the definitions used

We performed a systematic review of the prevalence of metabolically healthy obesity (MHO). Medline, Web of Science and EMBASE were searched for original articles from inception to November 2013. Only prospective and cross-sectional studies were included. After screening 478 titles, we selected 55 publications, of which 27 were population-based studies and were used in the narrative synthesis. From the 27 studies, we identified 30 definitions of metabolic health, mainly based on four criteria: blood pressure, high-density lipoprotein cholesterol, triglycerides and plasma glucose. Body mass index ≥30 kg m(-2) was the main indicator used to define obesity (74% of the studies). Overall, MHO prevalence ranged between 6% and 75%. In the studies that stratified the analysis by sex, prevalence was higher in women (seven out of nine studies) and in younger ages (all four studies). One-third of the studies (n = 9) reported the response rate. Of these, four reported a response rate of ≥70% and they showed MHO prevalence estimates between 10% and 51%. The heterogeneity of MHO prevalence estimates described in this paper strengthens calls for the urgent need for a commonly established metabolic health definition.