Cancer seems to strike at random, but a new study suggests that it’s not nearly as random as you might think. The study, published in the journal CA: A Cancer Journal for Clinicians, suggests that more than four in 10 cancers in the United States are a result of poor lifestyle choices, like eating unhealthy or cigarette smoking.

Scientists found that smoking was the biggest factor, followed by being overweight, excessive alcohol consumption, second-hand smoke exposure, eating red and processed meats in excess, and not getting enough vegetables and fruits in your diet. Not enough calcium, dietary fiber, exercise, and too much ultraviolet light were also risk factors, as were sexually transmitted diseases.

Specifically, out of 1.57 million cancer cases reported in 2014, scientists believe 42 percent were due to those risk factors, and 45 percent of deaths are caused by them. Smoking was tied to 19 percent of cancers and 29 percent of deaths.

“Contemporary information on the fraction of cancers that potentially could be prevented is useful for priority setting in cancer prevention and control,” the abstract states. “Herein, the authors estimate the proportion and number of invasive cancer cases and deaths, overall (excluding nonmelanoma skin cancers) and for 26 cancer types, in adults aged 30 years and older in the United States in 2014, that were attributable to major, potentially modifiable exposures (cigarette smoking; secondhand smoke; excess body weight; alcohol intake; consumption of red and processed meat; low consumption of fruits/vegetables, dietary fiber, and dietary calcium; physical inactivity; ultraviolet radiation; and 6 cancer-associated infections).”