Cancer - Its Connection to Being Obese and Overweight

Michael Burg, MD

It is possible to eat yourself into disease, even cancer. Not just one form of cancer, but MANY, 13 at last count.

Many know about the connection between obesity and diabetes, high blood pressure, and so-called “high cholesterol.” Also, you may be aware of links between obesity and heart disease, heart attacks, stroke, and many other conditions.

Much less known, but every bit as real and life-threatening is the connection between obesity and malignancy, the general medical term for cancer.

“Obesity” is not a term of shame or blame

Before I go on though, let me share a little information about the term “obesity.” It sounds pejorative, blaming/shaming, as though doctors are pointing fingers and calling people names. “You’re obese,” or “You’re morbidly obese” we seem to be shouting.

But, these are NOT terms of blame or shame. Rather, they are simply medical definitions that doctors actually must use in their charts to describe certain characteristics of some patients.

BMI or Body Mass Index

Many are familiar with the term BMI or Body Mass Index. This is simply a ratio of height to weight.

BMI is not the only measure of ideal body weight. For example, some muscular people have high BMIs but are actually lean, fit, and healthy with a low percentage of body fat. They are not obese.

Generally, though, a BMI of 18.5 to 24.9 is considered normal weight. A BMI of 25 to 29.9 puts you in the overweight category. Obesity is defined as a BMI of 30 or greater. Morbid obesity occurs when BMI is 40+.

Find your BMI on this table.

Again, BMI alone does not define perfect health. Nor is it the one and only measure to determine the risk of various health problems.

However, the connection between obesity and cancer is compelling and alarming.

The obesity-cancer connection

From the National Cancer Institute, this is the current list of cancers associated with being overweight and/or obese.

  • Endometrial cancer (cancer of the lining of the uterus)
  • Esophageal adenocarcinoma
  • Gastric cardia cancer (cancer of the stomach’s upper region)
  • Liver cancer
  • Kidney cancer
  • Multiple myeloma
  • Meningioma (cancer of the brain’s covering membrane)
  • Pancreatic cancer
  • Colorectal cancer
  • Gallbladder cancer
  • Breast cancer
  • Ovarian cancer
  • Thyroid cancer

Realize that no one has proven that obesity causes cancer, only that an association between obesity and cancer exists. This is like the discovery early on that smoking and lung cancer are related. In other words, smokers are more likely than non-smokers to develop lung cancer (and as it turns out many other diseases and conditions). Proof that smoking CAUSED lung cancer came later. That may be the case too for obesity and cancer. The “jury is still out” on this issue at the moment.

Right now though medical scientists have these ideas about why obesity increases cancer risk.

Chronic inflammation

The chronic low-level inflammation seen in obese individuals may cause DNA damage leading to cancer.

Excess estrogen

Fat cells (adipocytes) produce excess estrogen which is associated with an increased risk of developing certain cancers.

Increased insulin and insulin-like growth factor-1

As levels of these substances rise in the human body so too does the risk of certain cancers.

Other hormones and substances

Obesity may affect the number and type of cells the body produces, which may in turn lead to cancer. Cancer at its simplest level is unregulated or “dysregulated” cell growth, cell growth not under normal control.

Scope of the problem

As of 2012 experts estimated that 100,000 Americans per year develop overweight-related or obesity-related cancers.

What can you do?

Present medical evidence suggests that minimizing weight gain during adulthood lowers cancer risk. Weight loss — if you’re obese — may do the same, but the evidence here is less clear.

Reality check

I am well aware that weight gain is not always under one’s personal control. A wide variety of medical conditions predispose people to weight gain and the development of obesity.

However, a substantial percentage of obese Americans are obese because of dietary overindulgence and lack of physical activity.

So, do what you can do on your own to lose weight. Talk to your doctor or other healthcare professionals about weight loss programs and options that work. Diet generally don’t, in spite of their promises. Lifestyle changes and other measures do.

My situation

I’m not a skinny person. I was a skinny kid, but during my teen years and early adulthood I could properly have been described as “husky,” a kind term for overweight. I’ve never met the BMI definition of obese.

As of this writing, my BMI hovers between 26 and 27, not bad, but not ideal. I’m working on it. I have noticed that since becoming a vegetarian weight loss is easier to achieve (I won’t go into it here but I challenge you to watch two videos, “Forks Over Knives” and “Earthlings.” If you’re not a vegetarian after viewing those I’d be stunned.)

Also, I lose weight when I travel. Guess what, less easy access to excess food — particularly the standard American diet — coupled with more physical activity and, like magic, I lose weight. In 2003–2004 I lived in Amsterdam without a car. Like the Dutch, I either rode my bike everywhere or walked and took public transportation. I arrived there weighing 210 pounds and dropped to 190 in short order and stayed there. My height didn’t change, 74 inches. More recently, in March of 2020 as a 65-year-old, I worked on a farm in New Zealand. I’m still 6'2" and I arrived in NZ at 210 and dropped to 200 within 2 weeks.

Best of luck on your journey to better health and hopefully less risk of developing cancer and other maladies. I can be reached at if you’d like to chat.

Resources I relied on while preparing this article.

Comments / 0

Published by

Medical | Medical Humanities | Advice | Life | Self Help | Writing | Humor | Satire | Society | More

San Luis Obispo, CA

More from Michael Burg, MD

Comments / 0