What does your BMI really tell you and the sneaky things it doesn't. I want you to think back to when you were at the doctors and they weighed you, took your height and then looked at the chart to see where you fell with your BMI? First off what is a BMI chart? BMI, an estimate of a person’s body fat, is used to predict a person’s risk for chronic disease. BMI is calculated by measuring a person’s weight relative to their height, and is highly regarded by medical professionals as a good indicator of a person’s likelihood of developing diabetes, metabolic syndrome, and cardiovascular disease.
Using a BMI chart is a bit inconclusive of what is really going on with your body so why do health care practitioners use this as a guide to assess your health? It is a simple and noninvasive way to collect information about overall health. However, it is not always telling you the whole truth of what is going on. BMI becomes less useful when it comes to assessing the risk of an individual.Here are some of the limitations BMI has when looking at individuals.
1- Muscle to fat ratio based on weight can be very misleading. BMI is using your weight overall and doesn't measure fat to muscle ratio. Yes muscle does weigh more than fat and on a smaller individual, this can appear that you are "overweight" or "obese" on the BMI chart because it doesn’t take into account a lot of factors, such as body composition, age, and sex. BMI also doesn’t take into account weight differences among the body’s tissues such as muscle, bone, organs, stored water and fat. People who strength train consistently tend to have a greater amount of lean muscle mass than people who don’t strength train. Yet, with BMI all weight from fat mass and lean mass is created equal. Of course, higher amounts of physical activity and lean muscle mass are protective for health and longevity, so take this into consideration when assessing your BMI value.
2- Being thin, doesn't always mean you are healthy and the flip side is that being slightly heavier doesn't mean you are unhealthy. Thin individuals who lack of muscle mass and carry excess body fat are at just as much risk for chronic disease complications as their obese counterparts, especially when the excess fat is carried in and around the organs.Yet, by BMI standards these individuals would not be considered at risk for chronic disease.
3- Get a more accurate measure of body fat by getting body composition testing done. This can be in the form of skin fold caliper testing, DEXA scan, BodPod, or hydrostatic weighing. All of these tests will help provide you with a more accurate representation of your body composition in relation to muscle and fat tissue. Recommended body fat percentages for women for overall health are between 21 and 32 percent, and between 10 and 22 percent for men.A waist circumference greater than 35 inches for women and greater than 40 inches for men is considered as an independent risk factor for cardiovascular disease, cancer, and all-cause mortality.
Here is the truth, what you weigh is only a small spinet of your health overall. Most of the time excess weight is accompanied by other negative health behaviors such as poor diet, smoking, being sedentary, and high stress. By including regular strength training and a healthy diet, you can reduce excess body fat and overall risk for disease, regardless of what happens to BMI.