Healthy Weight and Survivorship

Article contributed by Mayo Clinic staff, Jackie See, Registered Dietician.

After a diagnosis of cancer, many people wonder what they can do to prevent recurrence or the growth of cancer.  You may or may not be aware that being overweight or obese increases the risk of developing 13 types of cancers.  Some of the most common cancers are postmenopausal breast, endometrium, colon, kidney and others.  Indeed, being overweight or obese is one of the leading causes of cancer and is also believed to affect survival.  If you are overweight, losing some weight may be one of the best things you can do to prevent recurrence or the growth of cancer.

Understanding weight and cancer risk

What is obesity and how does it lead to cancer?  When a person is overweight or obese, it means that they have too much body fat in relation to lean body tissue or muscle.  Weight is often measured with body mass index (BMI).  BMI is the ratio of a person's weight and height.  A healthy BMI is usually between 18.5 and 24.9. A BMI between 25 and 29.5 is considered overweight, while of BMI of 30 or higher is obese.  The higher your BMI the more likely you are to get certain types of cancer.

Too much body fat can increase cancer growth or outcome in several ways:

• Fat cells produce estrogen, and high levels of estrogen can promote the growth of some cancers such as breast and endometrial.
• Fat tissue produces proteins that cause inflammation, which can also promote cancerous changes in cells and tissues.
• Overweight or obese people often have higher blood levels of insulin and insulin growth factors that can encourage the growth of cancerous cells.

Research suggests that fat in your abdomen is even more active in producing these cancer growth stimulants.  So, people who carry their excess weight in the abdomen are at greater risk.

It's not too late

Maybe you are wondering if it does any good to lose weight at this point.  Lifestyle’s impact on survivorship is a fast growing area of study.  Research suggests that maintaining a healthy weight is associated with lower risk of cancer returning or dying as a result of cancer.

Perhaps you are discouraged after trying to lose weight for many years before being diagnosed with cancer.  Losing weight is challenging.  You may feel you have failed after so many attempts to lose weight but maybe you just have not found what works for you yet.  Talk with your doctor or ask for a referral to a registered dietitian. Many people find it easier to lose weight if they have a structured program and support.

Even if you do not reach an ideal weight, a weight loss of 5-10% of your body weight (i.e. 10-20 pounds in a person that weighs 200 pounds) is sufficient to reduce inflammation and lower levels of estrogen, insulin and other factors that promote cancer growth.

What you can do now 

The first step is to talk with your healthcare team about your weight.  They can help you determine if you are at a healthy weight and what impact your weight may have on your health.

Reducing the calories you eat and drink and increasing physical activity are the main ways to manage or lose weight.  The following lifestyle changes can help:

• Fill your plate with a variety of vegetables and other plant-based foods that can help you stay full while reducing calories.
• Avoid sugary drinks, including fruit juice.
• Limit foods high in fat and sugar, such as desserts, fried foods, candy and chips. These foods contain a lot of calories in a small portion.
• Be physically active for at least 30 minutes a day.

As cancer survivors are living longer after diagnosis, these recommendations also reduce the risk of developing other chronic illnesses such as diabetes and heart disease.  That is important because many long-term cancer survivors are at increased risk of heart disease.