There are many possible causes of back pain, and just as many potential contributing factors. Excess weight, in particular, can place added pressure on the spine and its supporting joints and muscles. According to the Centers for Disease Control and Prevention (CDC), more than 30 percent of Americans may be considered obese, defined as having a BMI (body mass index) of 30 or above. Consequently, it's an increasingly common contributing factor for many people who are living with some type of back pain.
Increased Discomfort from Disc Damage
Excess weight may place enough extra pressure on the spine to affect the spongy discs that cushion the spine. Over time, these discs may become damaged to the point where inner disc material presses outward and through the disc's exterior shell. It becomes a problem when material from the disc presses on nerve roots. Spinal joints may also become damaged enough to cause one disc to slip in front of an adjacent one, referred to as spondylolisthesis.
Obesity and Sciatic Nerve Irritation
Nerve irritation may also result in radiating nerve pain that affects the sciatic nerve, the longest nerve in the body that travels from the lower back through the legs. A study in China on weight and back pain noted that subjects with a higher BMI had more instances of degenerative disc disease, a wear-and-tear condition that may also damage discs enough to irritate nearby nerves. Added weight around the lower back sometimes increases pressure on the piriformis muscle in the buttock that helps with hip movements. Inflammation of this muscle may affect the nearby sciatic nerve.
Inflammation, Obesity, and Back Pain
People who are obese may suffer from chronic inflammation related to the way fat cells interact with other tissues. Persistent swelling of tissues can increase the risk of developing arthritis, a condition that can affect the bones and joints of the spine (facet joints). Arthritis of the spine may be further affected by lifestyle choices often linked to obesity, including:
- Lack of regular exercise
- Dietary choices that may contribute to inflammation (processed meats, sugary snacks, whole-fat dairy products, refined grains)
- Decreased muscle strength from a sedentary lifestyle
No single cause of back pain due to obesity has been proven. Yet people who are obese are also at an increased risk of developing conditions such as high blood pressure (hypertension) that may affect how nutrients are delivered to the spine and other underlying health issues can also impact the spine. There is also more than enough evidence to suggest that managing your weight can have numerous health benefits, with better overall spine health being one of them.