Growing Concern: The Links Between Cancer and Obesity

Dr. Christopher McGowan
December 10, 2020

Weight gain is not typically something that sneaks up on you overnight. It takes time to build up excess body weight. Cancer, on the other hand, can seemingly come at you out of the blue. What might seem like an innocuous health issue can suddenly stop you in your tracks when your doctor says, “You’ve got cancer.”

If you thought you were putting yourself at higher risk of a cancer diagnosis, you would probably make some lifestyle changes. Staying out of the sun or putting on sunscreen is a great way to avoid skin cancer. Lowering your intake of red meat has been suggested to have an effect on your rates of colon cancer. But what about being overweight? Could obesity put you at greater risk of cancer? It turns out that while there is no clear answer yet as to why, the numbers suggest you are in much greater danger of many types of cancer if you are overweight. 

Understanding the Link Between Weight Gain and Cancer Risk

To be clear at the outset, there is still little in the way of direct evidence for specific links between obesity and cancer, but large cohort studies and meta-analyses referenced by organizations such as the National Institutes of Health (NIH) and National Cancer Institute show worrying increases in the rates of many cancers among overweight individuals. Though the chances of some forms of cancer only show slight increases for people who are overweight, others are remarkably more likely. In some cases, your chances of getting certain kinds of cancer can more than double or be even four times higher if you have a body mass index (or BMI) that is greater than 30.

Unlike the clear link between high blood pressure and excess body weight, there is still more research needed to understand exactly how obesity and cancer are linked. How your risk for certain cancers are linked to excess body fat depends on many factors. Many processes in the body, including the regulation of hormones, can be affected by excess body weight. Research is still ongoing into the exact manner in which this increases your cancer risk, but some clues are emerging as research continues. What is clear is your chances are greater for getting certain cancers if you are overweight. 

The picture of obesity and cancer risk is further complicated because men and women are affected differently. It could even matter when during your life you gain weight. For example, obesity is linked to increased risk of breast cancer in postmenopausal women, but excess weight seems to have no significant impact on breast cancer rates in premenopausal women. Gaining and losing weight multiple times during your life may also have an effect.

Some cancers show stronger correlations to excess body weight than others. For example, esophageal and upper gastrointestinal cancers are more than twice as common among people who are overweight than their more trim counterparts. Chances for colorectal cancer, however, only increase by 30% and for multiple myeloma the chances are only 10%-20% greater.

How Does Body Weight Affect Cancer Risk?

The exact mechanism of how weight gain and cancer are linked is very complex. While other health concerns, such as sleep apnea, can be directly attributed to obesity, the link between cancer and being overweight is less clear. While data consistently shows that cancer occurs in higher rates among those suffering from obesity, understanding exactly why this is the case is difficult. 

One such indirect link is the decreased rates of physical activity among those who are overweight. Though lower levels of physical activity are not directly linked to cancer, they are strongly correlated to obesity. Excess body weight is linked to insulin resistance, and people who are overweight tend to have higher levels of insulin and blood sugar than people who maintain a healthy weight. Higher levels of insulin and insulin-like growth factor-1 (IGF-1) have been linked to increased rates of kidney, prostate, colon, and endometrial cancers. 

The very presence of fat cells in your body affects many different hormone levels, some of which can influence or inhibit cell growth. Excess adiposity (or the presence of fat cells) can change levels of leptin and other hormones that help regulate cell growth and proliferation. For example, people who are overweight tend to have lower levels of adiponectin, which may help limit the proliferation of cells. 

Types of Cancer Linked with Increased Weight

Weight gain is linked to increased incidence of many kinds of cancer. Though excess body weight is not often listed as the primary cause of many cancer cases, the higher numbers of cancer diagnoses among people struggling with obesity paints a clear picture of the increased risk of being overweight. 

The American Cancer Society identifies the following lists of cancers known to have been linked to obesity:

  • endometrial cancer (cancer of the lining of the uterus)
  • postmenopausal breast cancer 
  • kidney cancer
  • colorectal cancer
  • thyroid cancer
  • esophagus cancer
  • gallbladder cancer
  • stomach cancer
  • liver cancer
  • ovarian cancer
  • pancreatic cancer
  • multiple myeloma
  • meningioma (tumors in the lining of the spinal cord and brain)

While the cancers listed above show some of the strongest links, this is not the full list of potential cancer risks that increase if you are obese. Being overweight or obese might also raise the risk of other cancers, such as:

  • cancers of the larynx, throat, and mouth
  • non-Hodgkin lymphoma
  • breast cancer in men
  • aggressive forms of prostate cancer

Measuring Weight Gain

Historically, measuring obesity has been done by the rudimentary assessment of the body mass index. Since your BMI is only a measurement of your overall weight and its relationship to your height, it can only tell you so much about your body. Doctors and scientists have recently begun comparing the measurements around your hips and waist as a way to help understand how body fat is distributed. 

Research suggests the relationship of these two measurements may have greater utility in predicting how likely you are to be at increased risk for obesity related cancers. Though correlations can be identified between waist and hip circumference and some cancers, the hormonal and physical stresses excess adipose tissue places on organs is still being researched.

Does Losing Weight Reduce Cancer Risk?

Losing excess body weight has far reaching effects for your overall health, and this extends to cancer. Lower blood pressure, decreased inflammation, lowered insulin levels, increased physical activity, and better renal and liver function are all waiting for you as you shed excess fat.

Where this really hits home is for people who have been diagnosed with or already survived cancer. Quality of life, cancer progression, and survivorship rates are broadly better for people who weigh a healthy amount compared to those who are obese. The chances of side effects such as incontinence for prostate cancer survivors or lymphedema in women treated for breast cancer are higher when obesity is part of the picture. Cancer survivors who maintain excess body weight are at significantly higher risk of recurrences of cancer later in life than those who maintained a healthy weight.

Weight Loss, Cancer Prevention, and Long-term Health

When it comes to taking care of yourself, there are few better ways to improve your overall health than losing excess weight. Weight loss is one of the best paths to a lower risk of cancer, heart disease, type 2 diabetes, and many other health concerns. 

Lifestyle changes are not easy, and some people find that even after many attempts at diet and exercise, they still can’t shed those excess pounds. In these cases, turning to bariatric surgery or other weight loss procedures may be a solution. Health care professionals are usually reluctant to perform any abdominal surgery or procedure unless it is necessary, but the dire consequences to your health of being overweight often make weight loss procedures a compelling alternative to the increased risks to your health. 

In the United States, a lot of the focus on cancer prevention is focused on research into developing faster diagnoses and better treatments. While we wait for these new developments in oncology, there are steps you can take today to lower your risk of many kinds of cancer. Changing your lifestyle to help you work toward a more healthy weight is near the top of the list. If you have a BMI that classifies you as obese, have not been able to lose weight by simply changing your diet and exercise routine, and have other risk factors for cancer, type 2 diabetes or heart disease, it may be time see whether a weight loss procedure could be the answer you are looking for. 

True You Weight Loss exists to help people make informed decisions and take control of their weight loss goals. The medical importance of losing weight if you are obese is too great to ignore, and too complex to solve with one kind of solution. While gastric bypass surgery may have been the standard for years when it came to surgical weight loss, recent advancements have provided better alternatives that can provide you the results you need without the risks associated with traditional bariatric surgery. 

Not everyone is a candidate for weight loss surgery, or even for weight loss procedures such as an endoscopic sleeve gastroplasty. This does not mean you are out of options, though. Other solutions like the ORBERA® Managed Weight Loss System can help you lose weight without the risks of a full surgery. Our medical nutrition therapy program is another alternative for people who simply need someone to work with them as they move toward the freedom of finding and maintaining a healthy weight. 

If you are concerned about your current body weight because of the higher risk of cancer, or the many other diseases and conditions associated with excess body weight, request a consultation with us at True You today.

Dr. Christopher McGowan
Dr. Christopher McGowan

Dr. Christopher McGowan, MD, a leader in endobariatrics, specializes in non-surgical obesity treatments and is triple-board-certified in Internal Medicine, Gastroenterology, and Obesity Medicine. Renowned for pioneering endoscopic sleeve gastroplasty (ESG) with over 2,000 procedures, his global influence and research contributions define him as a top expert.

Get Monthly Updates About Nutrition and Advancements in Weight Loss

You might also be interested in:

Learn more about our non-surgical weight loss solutions with a quick consultation.

0% interest financing available.
Discover which solution is right for you.
Go over pricing & payment options.

Fill out the short form to learn more!

Request a Free Consultation

Subscribe to our newsletter for exclusive insights, success stories, and expert tips on non-surgical weight loss. Join our community and stay informed on the latest advancements in endobariatric procedures.
 True You Weight Loss | All rights reserved