In the US, overweight and obesity contribute to 14%-20% of all cancer-related deaths …observational studies show that obesity increases the risk for cancers of the pancreas, gallbladder, thyroid, ovary, and cervix, and for multiple myeloma, Hodgkin lymphoma, and aggressive prostate cancer. The link between body weight and cancer risk is believed to stem from multiple effects on fat and sugar metabolism, immune function, level of hormones (including insulin and estradiol), and cell growth.

Lessen your risk by following these healthy steps:
Maintain a healthy weight throughout life.
• Balance caloric intake with physical activity.
• Avoid excessive weight gain throughout life cycle.
• Achieve and maintain a healthy weight if currently overweight or obese.

Adopt a physically active lifestyle.
• Adults: Engage in at least 30 minutes of moderate to vigorous physical activity, above usual activities, on 5 or more days of the week; 45 to 60 preferable.
• Children and adolescents: Engage in at least 60 minutes per day of moderate to vigorous physical activity at least 5 days per week.

Consume a healthy diet, with an emphasis on plant sources.
• Choose foods and beverages in amounts that help achieve and maintain a healthy weight.
• Eat 5 or more servings of a variety of vegetables and fruits each day.
• Choose whole grains in preference to processed (refined) grains.
• Limit consumption of processed and red meats.
If you drink alcoholic beverages, limit consumption.
• Drink no more than 1 drink per day for women or 2 per day for men.

From:  American Cancer Society. Cancer Prevention & Early Detection Facts & Figures 2011. Atlanta: American Cancer Society; 2011