​Unhealthy lifestyle and dietary habits, such as cigarette smoking, alcohol intake, physical inactivity, and consumption of diets high in red and processed meats and low in fruits, vegetables, fiber, and calcium, may increase an individual's risk of developing cancer.

This study examined how lifestyle and dietary choices affect cancer risk. A team of researchers from the American Cancer Society reviewed data obtained from the Center for Disease Control and Prevention (CDC) and the National Cancer Institute on the number of cancer cases and deaths that occurred in the United States in 2014.

The team of investigators discovered that unhealthy lifestyle and dietary habits, such as cigarette smoking, high exposure to second hand smoke, alcohol consumption, high dietary ingestion of red and processed meats, low intake of fruits, vegetables, fiber, and dietary calcium, physical inactivity, excess body weight, ultra-violet radiation, and cancer-associated infections, were associated with 42% of all incident cancer cases (with the exception of non-melanoma skin cancer) and 45.1% of all cancer deaths recorded in the United States in 2014. According to this study, cigarette smoking was responsible for the highest number of cancer cases and cancer-related deaths, followed by excess body weight. Lung and colorectal cancer were the most common cancers in the United States in 2014. The findings of this study suggest adoption of healthy lifestyle and dietary habits may help reduce the incidence of cancer in the general population.