Body Weight and Cancer Risk

Being overweight has been linked to having a higher risk of 13 different cancers. These include cancers of the: 

• Breast (after menopause).
• Colon & rectum.
• Esophagus.
• Stomach.
• Liver.
• Gall bladder. 
• Pancreas.
• Endometrium.
• Ovary. 
• Kidney. 
• Prostate.
• Thyroid. 
• Multiple myeloma. 

Too much body fat raises your risk of cancer in a few ways: 

• Extra body fat makes higher levels of some hormones and proteins that may cause cancer cells to grow. These include insulin, leptin, and estrogen, among others. 
• Fat cells make substances that cause chronic inflammation, which is linked to increased cancer risk. 
• Research has also shown that people with extra fat around the waist (the “apple shape”), may be at higher risk because this fat causes even more cell growth, increasing the risk of cancer.

Bodyweight is measured using body mass index or BMI. BMI is a measure of body fat, based on your height and weight. The BMI chart classifies your body as underweight, healthy, overweight, or obese. This is a good place to start to figure out your body weight and see where you fall on the chart.

A healthy diet, mixed with regular physical activity and keeping a healthy weight has been shown to reduce cancer risk. These three things are the second most important step (after not smoking) in preventing cancer. A few studies have found that losing weight can help decrease the risk of weight-related cancers. The most evidence for losing weight to lower cancer risk comes from studies of people who have had bariatric (weight loss) surgery. In a sample of these patients, cancer death rates were 38% lower than people who were obese and did not have surgery. 

Losing weight is not easy. It takes a lot of effort to make big lifestyle changes. Seek support from friends, family, your healthcare providers, and weight loss programs. Look into websites or applications (apps) to track progress and motivate you. Get started by learning more at the American Cancer Society.

Resources to learn more about how diet, physical activity, and weight are related to cancer:

• American Institute for Cancer Research.
• Take Control of Your Weight at the American Cancer Society website.
• Eat Healthy and Get Active at the American Cancer Society website.
• Dietary Guidelines for Americans, 2020-2025 from the USDA.
• The US Department of Health & Human Services Physical Activity Guidelines for Americans, 2nd edition (2018).
• NIH AARP Diet & Health Study: a study developed at the National Cancer Institute of the National Institutes of Health to improve our understanding of the relationship between diet and health.
• The European Prospective Investigation into Cancer & Nutrition (EPIC): A large study by the International Agency for Research on Cancer investigating the relationships between diet, nutritional status, lifestyle and environmental factors and the incidence of cancer and other chronic diseases.