 This systematic review investigates the clustering and predictors of risk behaviors such as smoking, physical inactivity, unhealthy diet, alcohol misuse and sexual risk behavior among adults and young adults in the UK. The results show that there is strong evidence of clustering between certain risk behaviors with the most commonly identified cluster being alcohol misuse and smoking among general adult populations. Young adults showed consistent evidence of clustering between sexual risk behavior and substance misuse. Socioeconomic status was found to be the strongest predictor of engaging in multiple risk behaviors. The findings suggest potential for interventions targeting multiple risk behaviors, either sequentially or concurrently, particularly where there is evidence of clustering. Additionally, there is potential for intervening at the social or environmental level due to the strong association with socioeconomic status. This article was authored by Nick Meadar, Kristel King, Theraman Moe Byrne and others. We are article.tv, links in the description below.