Has your primary care doctor or spine physician suggested you lose weight to help reduce the severity of your lower back pain? Maybe you have back pain, but haven’t considered extra body weight to be a potential cause. Even an added 10 pounds can contribute to increased back pain.

The results of a large cross-sectional population-based study confirmed the link between obesity and lower back pain. The study involved 6,796 adults, and researchers found the risk for low back pain increases as body mass index (BMI) does. The risk of low back pain among adults who are extremely obese is four times greater than among normal-weight adults.

BMI and What It Means
BMI is a number based on your weight and height. In general, the higher the number, the more body fat a person has. There are four categories of BMI:

• Normal weight—BMI less than 25
• Overweight—BMI of 25 to 30
• Obese—BMI of 31 to 35
• Extremely obese—BMI of 36 or higher

For example, a person who is 5’10” tall and weighs 174 pounds has a BMI of 25, while a person who is 5’10” and weighs 251 pounds has a BMI of 36.

Obesity and risk for low back pain by the numbers

• 2.9% for people of normal weight
• 5.2% for overweight adults
• 7.7% for obese adults
• 11.6% for extremely obese adults

The study did not address why obesity increases the risk of low back pain. However, extra body weight can contribute to how the spine functions—its mechanical well-being.

Small Changes
Small changes in the level of activity can substantially reduce the risk for low back pain. People with extreme obesity (BMI 36+) who increase their time in moderate activities 17 minutes per day may reduce their risk for low back pain by 32%. Moderate activities may include briskly walking, performing water aerobics, riding a bike, ballroom dancing, and gardening.