This chapter focuses on modifiable risk factors to health, including smoking, alcohol consumption, illicit drug use, unhealthy nutrition, lack of physical activity and obesity. Despite progress in reducing smoking rates over the last decades, about one‑fifth of adults still smoke every day and tobacco consumption remains the largest behavioural risk factor to health, accounting for about 700 000 deaths per year across EU countries. Alcohol consumption is responsible for another 255 000 to 290 000 deaths per year across EU countries. While alcohol control policies have achieved progress in reducing overall alcohol consumption, heavy alcohol consumption remains an issue among a sizeable share of adolescents and adults: more than one in five adolescents aged 15 report having been drunk more than once in their life and one‑third of adults report regular heavy drinking. The use of illicit drugs is another important public health issue in Europe: about 15% of young people aged 15 to 34 report having used cannabis in the last year. Weight problems are widespread in most EU countries, with nearly one in five adolescents overweight or obese on average across EU countries in 2018 and more than one in six adults obese. Overweight and obesity is driven by unhealthy nutrition habits and lack of physical activity. Only one in seven 15‑year-olds on average across EU countries report doing at least moderate physical activity at least one hour daily, and less than half report eating at least one fruit or vegetable per day. Large socio-economic inequalities exist for most risk factors to health. For example, overweight and obesity rates among children and adolescents are 50% greater among those living in the least affluent families than those living in the most affluent.