According to a new report, which was published the American Cancer Society, four in 10 cancer cases and nearly half of cancer deaths in Americans over 30 are linked to smoking cigarettes, being overweight, using alcohol, being inactive, eating a poor diet and getting too much sun.  

Other factors, like secondhand smoke exposure, eating red meat, having unprotected sex, leading to HPV or HIV infection and a diet low in calcium, were also identified as the cause for a number of cancer cases, but caused a fraction of the cases compared to the top six categories. HALF of all cancers are caused by six lifestyle factors, study finds - how many are YOU guilty of? | Daily Mail Online