Low back pain (LBP) can have many causes such as genetics, acquired abuses, body type (especially obesity—body mass index or BMI >30), gender, as well as cultural aspects that predispose one to acquire low back trouble. So, the question remains, "What can I do to reduce my risk for developing low back pain?"
The answer, like the cause is—you guessed it—multifactorial. Since we can’t change our genetics, we’ll have to accept that one. But, we can change our BMI by keeping our weight to a reasonable amount. In an April 2010 study, 60,000 Norwegian men and women provided BMI information and 20.9% of the men and 26.3% of the women indicated they had chronic low back pain. The authors found a direct relationship between a high BMI and an increased prevalence of LBP. Similar results attributing obesity to LBP were also reported in a meta-analysis published in January 2010 in the American Journal of Epidemiology (2010; 171(2):135-154).
So, what is, "…a reasonable amount of weight?" A BMI of 18.5 to 25 is considered "normal," while 25-30 is described as overweight, and >30 represents obesity. We should also mention anything LESS than 18.5 is considered underweight and that’s not good either as many of the body's nutritional needs may be unmet and too little weight can negatively affect bone health leading to osteoporosis and a myriad of other problematic health issues.
You may be wondering what a body mass index or BMI is, as its quite important and is quickly gaining respect in the medical world. In fact, it has been suggested that clinicians record BMI along with the other "vital signs" like blood pressure (BP), pulse, breathing rate, height, weight, and temperature. The BMI is a formula of height and weight and it’s a rough calculation of our total body fat, which can be associated to our risk of disease and premature death. However, according to the National Heart, Lung and Blood Institute (NHLBI), it’s a little more complicated than that as people with greater muscle mass (such as a body builder) will have a higher BMI that suggests they are overweight. At the other end of the spectrum, older individuals who have lost muscle mass may be still be overweight but their BMI will not reflect that.
The NHLBI reports three factors of importance when defining obesity and its many negative health effects, including the increased prevalence of LBP. These factors are: 1) BMI; 2) the waist measurement; 3) the presence of other negative health factors including high BP, high LDL-cholesterol, low HDL-cholesterol, high triglycerides, high blood sugar, a family history of heart disease, physical inactivity, and smoking cigarettes. If you have a waist size >35" (~89 cm) for woman, >40" (~102 cm) for men, AND two or more of the previously listed risk factors, simply put, you MUST lose weight! Even a small weight loss of 10% (such as 30 lbs if you’re 300 lbs), will help lower your risk of developing diseases associated with obesity such as heart disease, stroke, certain types of cancers, and type 2 diabetes.