Obesity and Lower Back Pain

While it may seem reasonable to suggest that obesity places undue stress on the pelvis, back, and spine—triggering the development of chronic back pain—the association has long been a point of contention among researchers.

On the one hand, there are those who believe the cause-and-effect is clearly established: that excess weight pushes the pelvis forward and thereby strains the lower back.

On the other, there are those who believe that body mechanics alone is far too simple an explanation for a condition that can differ significantly from one person to the next and even those of similar age, body type, and experience.

Research Supporting Obesity as a Cause

From a statistical point of view, there appears to be a strong and almost incontestable association between weight and lower back pain.

A 2010 review published in the American Journal of Epidemiology assessed data from 95 high-quality studies and concluded that the risk of lower back pain was directly related to increases in body mass index (BMI).

The figures were largely unsurprising. According to the research, people of normal weight were at lowest risk, overweight people had a moderate risk, while those who were obese had the highest risk overall. The study also found that overweight and obese people were more likely to seek medical care to treat their pain.

A 2017 study from the University of Tokyo Hospital in Japan came to a similar conclusion. In reviewing the medical history of 1,152 men from 1986 to 2009, the researchers found that a person's BMI, combined the body fat percentage, directly corresponded to both the risk and rate of back problems.

Research Questioning Obesity as a Cause

However, others insist that the relationship is not so cut-and-dry. In 2017, a collaborative research effort coordinated by Cornell University aimed to evaluate which types of back or spine problems were related to obesity.

Using data from the 2014 Medical Expenditure Panel Study (a large-scale national survey of health providers, employers, and individuals), the researchers specifically looked at four common disorders:

• Lower back pain
• Spondylosis (spine degeneration)
• Internal disc disruption (IDD)
• Neck problems unrelated to spondylosis or IDD

What the researchers found was that obesity (as measured by a person's BMI, body fat, and hip-to-waist ratio) was a strong predictor of lower back pain and IDD but not the other two conditions.

What this suggests is that, while a connection clearly exists, there are likely other factors beyond body mechanics that contribute. If not, they would have likely seen the same increase in the rates of spondylosis as they did IDD.

It is possible, say the researchers, that increases in adipose (fat) tissue may trigger metabolic changes that play as much a part of back troubles as the weight itself.

It is equally possible that weight is not so much the cause of a back problem as it is a complicating factor. A 2015 study published in the Medical Archives Obesity came to this conclusion after reviewing the medical history of 101 men employed in similar job types.

What they determined was that obesity did not exert a direct influence on back pain but rather hastened or worsened underlying disorders (including herniated disc, ligament hardening, and spinal arthritis).

Insofar as biomechanics were concerned, obesity was seen to cause the abnormal redistribution of body weight that simply added to the wear-and-tear that already existed.

Common Back Problems Affected by Obesity

Whether obesity is the cause or contributor to lower back pain, it is clear that the excess weight can do the back little good. As a structure that helps support the body and influence movement, the back has a normal spinal curve that is most effective in a neutral position.

When a person is obese, any added weight in the midsection shifts the pelvis forward and causes the spine to curve excessively inward. We call this hyperlordosis or swayback. It is a condition that exerts abnormal pressure on back muscles that are forced to bear the weight.

Exercises designed to strengthen the lower abdominal muscles may help counteract this effect and bring the pelvis back into a neutral position. But, more importantly, the loss of weight is key to relieving the strain on the back and spine.

Obesity can also exacerbate other common back conditions. Among them:

• A herniated disc is one of the more common spine injuries for which people seek care. If you are overweight or obese, your body mechanics may play a role in both the onset and duration of the condition. Symptoms include sciatica and/or lumbar radicular pain (a shooting pain associated with a pinched lumbar nerve). People who are obese are also more likely to have slightly worse results after surgery to repair a herniation compared to those of normal weight.
• Spine osteoarthritis is known to be aggravated and accelerated by obesity. While excess weight can lead to joint misalignment, it is strongly believed that adipose tissue in the trunk can affect degenerative changes in the spine by creating a persistent, localized inflammation in and around the areas of damage.

A Word From Verywell

If you are overweight or obese, it is entirely possible that the extra weight you are carrying is placing undue pressure on your back and spine. But it doesn't mean that it's the only cause. If you are experiencing back pain or disability of any sort, have it checked out to determine the underlying cause, contributing factors, and appropriate course of treatment.

Beyond that, losing even 10 percent of your body weight will likely do you a world of good and may even reverse many of your back symptoms. Start there, and ask your healthcare provider for referrals to a qualified nutritionist and fitness expert who can help.