Weight Loss & Cancer: When Dieting Could Threaten Your Life

Tuesday, October 3, 2006 - 2:00pm

By Erin Dummert RD, CD

The first side effect of cancer is often weight loss. Even before being diagnosed, people with many types of cancer lose a significant amount of weight. Many people do not consider this side effect undesirable. In a country where 44% of adults are currently on a diet, many are simply happy to lose weight easily for the first time in their lives. However, weight loss during cancer treatment is risky and can compromise the effectiveness of treatment.

Being overweight increases cancer risk

Considerable scientific evidence shows that being overweight increases the risk for many diseases including all types of cancers. Reaching and maintaining a healthy body weight can dramatically decrease cancer and other disease risk. However, once a person is diagnosed with cancer, the benefits of weight loss diminish. Cancer treatment is a time for healing and building new healthy cells. Often the body needs extra calories and protein to accomplish this goal. Therefore, weight loss during this time can be detrimental to treatment.

Avoid weight loss during cancer treatment

Cancer patients are often told that weight loss is a normal part of cancer treatment, which may mislead them to think that it is acceptable. However, the negative effects of weight loss during cancer treatment are well documented, and minimizing this result should be a primary goal.

Some people experience a reduced appetite during cancer treatment and assume that they do not need to eat. However, people with many types of cancers, including lung, esophageal, gastric, colon, and others often require up to 1000 extra calories a day just to maintain their weight. Unfortunately, their appetite does not reflect this extra need and fools them into thinking their stomach has shrunk. In reality, it is more important than ever to eat enough to meet these needs.

But I want to be thin

Despite the known risks of weight loss, the concept of maintaining weight is difficult for many people to accept. People are so enamored with being thin that they often lose sight of the big picture. Losing weight and building new tissue are two opposing concepts. If the body is in a state of loss, it is extremely difficult for it to heal. If you have breast cancer, for example, it is hard for the body to lose weight and still build new healthy tissue in the breast. Even if a patient starts out weighing 500 pounds, it is recommended that they stay as close to that weight as possible during their treatment.

There is a time for healthy weight loss, but it is not during cancer treatment. Once all cancer treatment has been completed and your oncologist feels it is safe to start losing weight, you can embark on a healthy weight loss program knowing that you have done everything you could to help your body heal during your treatment.

Wait to lose weight

Although weight loss is a common side effect of cancer and cancer treatment, you should make every attempt to keep it to a minimum. Cancer treatment is not a time for dieting with the intent to lose weight. By eating enough calories to maintain your weight you will support your immune system, assist in the healing process, and be more likely to receive planned treatments, increasing your chances of finishing treatment on time.