A 2003 study in the New England Journal of Medicine estimates that being overweight or obese may contribute to up to 20 percent of all cancer-related deaths. Being overweight or obese (a BMI of 25 or greater) is strongly associated with specific types of cancer, including breast (postmenopausal), colon and rectum, kidney, esophagus, pancreas and gallbladder. It's also likely associated with cancer of the liver, cervix, ovary, prostate, non-Hodgkin lymphoma and multiple myeloma. The reason for the association may be related to negative effects on the immune system and inflammation, including hormones that stimulate cell growth. Many of the recommendations by the AICR for cancer prevention also help with achieving and maintaining an ideal body weight, such as increasing physical activity, limiting foods dense in calories like fast food, fried food and sweets and increasing fresh produce in the diet.

Read more: 28 Eating Secrets to Help You Lose Weight