8 Surprising Ways Belly Fat Can Cause Back Pain

Belly fat is a multi-pronged threat to your back and spine health.

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Do you find it hard to zip your jeans these days? Welcome to the bulging belly club, which has (ahem) grown a bit since the start of the COVID-19 pandemic. Around 37% of Americans say they’ve gained weight since it started, according to a global Ipsos survey released in 2021.

Illustration showing belly fat effect on back pain and spineBelly fat is a multi-pronged threat to your back and spine health.

If you live with back pain and have a lot of excess weight around your middle (abdominal obesity), your problems won’t just be fashion related. Too much belly fat is linked to back pain in a number of ways.

1. Belly Fat Can Affect Your Posture

When the natural curves of your spine are normal, you have a stable, well supported core. Excessive weight, including a large abdomen, pulls these curves out of alignment – a contributing factor in back pain.

Several studies have linked excessive abdominal fat with lordosis, an excessive inward curve of the spine – specifically toward the lower back. (Think swayback.) A study published in Obesity Surgery found that severely obese people had both pain and significant changes in posture, especially in the spine, knees and feet.

2. “Front-loading” Is Only Part of the Story

The back pain you may feel from a big belly isn’t just due to a shift in body mechanics. One reason we know this is by looking at another type of front-loading: breast implants.

Studies show these don’t have a similarly negative impact on back pain or posture. Marco Mazzocchi, PhD, an assistant professor in the Department of Plastic Surgery at the University of Perugia in Italy, writes that in many cases, implants improve both self-confidence and posture “regardless of the changes in body mass due to implants.” The weight of breast implants is typically less and is also carried by the thoracic spine which can explain the difference as well.

3. Extra Weight Can Overload Your Discs

In addition to postural changes, obesity can damage shock of absorbers of the spine.  It can lead to increased disc pressure, annular tears and herniation, as well as neurologic impingment by compressing the disc space and pinching the exiting nerves.  The spare tire in your belly can shorten the height of your intervertebral discs like a flat tire in an overloaded car.

4. Fat Can Release Harmful Chemicals

Your spare tire isn’t just a blob of inert tissue. Fat can secrete chemicals that contribute to painful inflammation. Over time, these chemicals can wear down components of your skeleton.

Belly fat may have a more important role in this chemical release than fat deposits elsewhere. Consider the study in PLOS ONE that examined potential links between obesity and degenerative disc disease. Researchers found a connection in obese men, but not in obese women. They suspect this is because men tend to store fat in their bellies, whereas women tend to store it in their buttocks and thighs. Weight carried in the abdomen can accentuate lordosis while weight carried in the legs tends to do so less.

Mechanical stress – in this case, the extra force placed on the spine by a large abdomen – is a factor in disc degeneration. But the authors also say metabolically active fat tissue has an important role in disc degeneration as well.

5. Belly Fat Can Damage Your Bones

Your bones constantly renew themselves, but body fat can interfere with the process – potentially leading to osteoporosis over time. Visceral fat, which is fat deep inside the abdomen (as opposed to subcutaneous fat, which is the pinchable stuff just below your skin), could have a significant role.

Illustration of types of fatBelly fat aka visceral fat is usually considered the most detrimental to your health, but don't forget subcutaneous fat either.

Several studies associate visceral fat with lower bone mineral density, as well as increased risk of some types of fractures. However, it’s worth noting that not all scientists agree that visceral fat is the problem. Some say the damage occurs with high body mass and excess weight, not just high levels of visceral fat.

6. “Pinchable” Fat Is a Problem, Too

When medical experts talk about the dangers of belly fat, they’re often talking about visceral fat. It’s linked with a host of health issues, including heart disease. But subcutaneous belly fat, also known as outer abdominal fat (OAF), may also pose problems for your body and back.

In one study, researchers looked at CT scans of more than 600 people to learn more about OAF as we age. They found that facet joint arthritis (in the lower back) is associated with an increase in OAF. For obese people with this type of arthritis, weight loss and pain relief may well go hand in hand.

7. Belly Fat Interferes With Ankylosing Spondylitis Treatment

If you have ankylosing spondylitis (AS), you’re no stranger to chronic back pain. The inflammatory disease can cause vertebrae to fuse over time. Your back might be super stiff, or you might have a permanently hunched posture.

Disease-modifying medications can improve symptoms and slow the disease process. However, being overweight can reduce the drugs’ effectiveness. Belly fat in particular has been singled out as a problem for drug absorption.

For a study in Clinical and Investigative Medicine, scientists set out to discover if visceral fat – not BMI – independently predicted diminished response to the disease-modifying drug infliximab. They found that it did. In fact, they found a significant correlation between visceral fat tissue and disease activity in people with AS who received this treatment.

8. Obesity Is Linked to a Rare Spinal Condition

Being obese doesn’t necessarily mean you have a lot of belly fat – though many obese people do. If you’re obese and have a high BMI, be aware that you may be at increased risk of a rare condition called spinal epidural lipomatosis (SEL), an overgrowth of body fat in the spinal canal. SEL can cause several types of back pain, so it’s always a good idea to have a doctor evaluate your aches instead of ignoring them or exclusively self-treating your pain.

While being overweight has its own medical problems, it is also a serious risk factor for both mechanical and chemical causes of back pain, as well as long-term implications in spine health.

Updated on: 04/20/21
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Obesity and Degenerative Disc Disease
Jason M. Highsmith, MD
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