Study Finds Link Between Belly Fat and Chronic Pain, but Which Causes Which?

By Crystal Lindell

A new study shows a link between abdominal fat and chronic musculoskeletal pain, but even the authors admit that it’s unclear which one causes which. 

The study, published in the American Society for Regional Anesthesia & Pain Medicine, found that abdominal adipose tissue (fat) is associated with chronic pain in multiple sites and widespread chronic pain. It also found that women were at higher risk for this association than men. 

“Reducing abdominal adiposity may be considered a target for chronic pain management, particularly in those with pain in multiple sites and widespread pain," wrote lead author Feng Pan, PhD, Senior Research Fellow at the Menzies Institute for Medical Research in Australia. “The identified stronger effects in women than men may reflect sex differences in fat distribution and hormones.”

In layman's terms, they’re suggesting that chronic pain patients be told to lose weight. Especially if they are women.

However, further down in the study, while discussing its limitations, they admit that the research does not “address the issue of potential bidirectional causality.” In other words, they cannot say whether excess abdominal fat causes chronic pain, or whether chronic pain causes excess abdominal fat. 

The researchers looked at health data from 32,409 people taking part in the UK Biobank study, a large research study with half a million UK participants.

The study used MRI images to measure visceral adipose tissue (VAT), which is fat that surrounds the organs in the abdominal cavity, such as the liver, stomach and intestines. They also measured subcutaneous adipose tissue (SAT), the layer of fat that sits between the skin and muscles in the body. 

Participants were asked if they had pain in a specific area of their body or all over their body for more than three months. 

Two years later, all the assessments were carried out again in 638 people in the group.

The results showed that the more fat people carried around their abdomens, the higher their chance of reporting chronic musculoskeletal pain.

To weed out contributing factors, the researchers adjusted for many things, such as age, height, ethnicity, household income, education, alcohol frequency, smoking, physical activity, comorbid conditions, sleep duration, psychological problems and follow-up time.

While a specific link between abdominal fat and chronic pain may be new, the idea that fat could contribute to chronic pain by making people more sedentary and less likely to exercise has a long history.

However, as a patient who gained weight after developing chronic pain and being put on a number of medications that had weight gain listed as a side effect, I’m always extremely skeptical about which causes which. 

Especially because I gained and lost weight multiple times over the 11 years that I’ve been in pain, and have never noticed either one impacting my pain levels. 

In my experience, many doctors are quick to dismiss symptoms when they can blame a patient’s weight as the cause. Even when the excess weight was literally caused by medications they prescribed. 

Doctors use studies like these to blame pain patients for their problems, while absolving themselves of any responsibility to help. Patients are told their pain is their fault, and if they’d just lose weight, they’d feel better. 

Then, when losing weight proves predictably difficult, the doctor can throw up their hands at the whole situation and proclaim that the patient must not want to get better. In other words, doctors set an impossible standard for patients and then blame the patient when they fail to meet it. 

As new weight loss GLP-1 medications like Ozempic and related drugs become more popular, it will be interesting to see how they impact conversations about weight loss and chronic pain. If the medications are as good as they claim to be at helping people lose weight, we might finally get some large-scale research into how losing weight actually impacts pain levels. 

And if more patients are able to lose weight when their doctors tell them too, physicians may find that they have to do more than just tell their patients to “lose weight” when it comes to treating pain.