I consistently have patients tell me that they need to lose weight because their BMI is too high. When I hear this, I want to know a lot more about the individual before I determine their individual nutrition needs!
BMI is defined as a person’s weight in kilograms divided by the square of height in meters. Sounds pretty simple right 🙂 This number is then used to categorize the individual into one of many categories including underweight, normal weight, overweight and obese. Medical professionals and insurance companies often use this number to determine if an individual is at increased risk for certain health conditions and chronic diseases. According to the CDC, BMI can be used as a screening tool to assesss health but several other assessments need to be performed to determine actual health status.
As a registered dietitian, BMI is only a very small portion of what I look at when assessing a patient or client. The reason I do not put a lot of value on this ONE number is that it does not take into account muscle mass or bone mass. Someone with a lot of muscle will naturaly weigh more than someone with very little muscle and therefore have a higher BMI. It also does not consider important lifestyle factors that drastically affect someone’s health. For example, someone can have a BMI in the healthy range, smoke three packs of cigarettes per day, not get any physical activity and skip several meals throughout the week. When only looking at BMI, this person would be considered more “healthy” than someone with a BMI slightly in the “overweight” category that does not smoke, eats healthy meals and snacks and gets regular physical activity that increases muscle mass. See how this doesn’t really add up??
So, it is important to remember that weight and BMI are not the only things to consider when evaluating your health. In my opinion, BMI is one of the last things to look at when evaluating health status (if you look at it at all!!). Think about your lifestyle choices and how you feel overall. Also get routine labs done to ensure that things in your body are working properly. If you have concerns about your weight and/or health it is important to talk to a dietitian or medical provider to determine ways that you can improve your health.