Should our goal be to achieve a normal Body Mass Index (BMI)?
What is BMI?
Body Mass Index or BMI is a scale that was first used by Pediatric Doctors to inform parents if their babies body weight is low, normal, or overweight. They start using this scale from the age of 2 through the age of 20 when your child gets transferred over to an adult clinic. They calculate it by taking your body weight (kg)/your height (m)^2. Based on what other children weigh and how tall they are around the world is the information a panel of Doctors used to decide what scores should be considered low, normal, overweight, and obese.
This scoring system seems skeptical and subjective when think about it. Until your child starts maturing and putting on muscle mass these charts are probably a good indication of your child's health. However 20 years old should not be the age when Doctors stop using this graph.
When our children get to the maturation phase of puberty they have the ability to put on muscle mass at a more accelerated rate than adults can. This is going to greatly increase their weight in a functional, aesthetic, and healthy way irrelevant of their height. This is going to skew the scores that Doctors are comparing your child to. Boys and girls can be early bloomers, meaning they start this phase between 11 and 13 years of age or they may be late bloomers and start this between 15 and 17 years of age. In my opinion they should stop using this scale to assess whether a child is healthy once they are in maturation.
You might be thinking, but they have adult BMI scales and we could just switch those maturing kids over to that one. Yes there are adult BMI scales, which are calculated the same way, but the difference is that the low, normal, overweight, and obese scores were decided not based on other adults around the world but for what scores a panel of Doctors decided is healthy and which ones are not. There are so many tests in the medical community that there is published research to support to help guide us to better health. The BMI score is a test that is insulting and is a horrible predictor of our health.
I have my BMI Score, Now What...
After your BMI score is calculated, you normally are told to exercise more or less and eat differently. Whether or not your blood work and blood pressure are in healthy ranges, Doctors typically just give you a list of foods to eat more of and which ones to avoid. Then they wish you luck and you're out of there.
I can tell you personally that my blood work is fantastic and I've studied lots of research and books that go beyond my masters degree in kinesiology to help guide me how to dramatically impact my blood panels. However I can tell you that I've never had a normal BMI in my lifetime. I recently had my BMI calculated and was awarded a score of 27.86.
To barely scrape into the "Normal" category I'd have to get my weight down to 152lbs. I currently weight 188lbs. I then went and calculated my body fat % using skin fold calipers which I've been doing on hundreds of people for over 10 years. My body fat % is 12.14. This means I have 22lbs of fat dispersed across my body. Even if I lost all of my essential and non-essential body fat I could not achieve a weight of 152lbs. If I start losing bone and muscle mass on top of all my fat maybe I can get there.
What should our goal be instead of BMI?
Your initial goal should be to get your blood work in healthy ranges:
- Have a 1:1 between your triglycerides and HDL cholesterol
- Score above 40 on a vitamin D test
- Have healthy thyroid levels
- Have an 80-90 on fasting blood sugar
- Have a 5.5 on your Hba1c
Have healthy physical qualities:
- Have a blood pressure of 120/80
- Have a resting heart rate <60
- Have a body fat % between 10-20% if you're a man
- Have a body fat % between 15-25% if you're a woman
I could keep going and add nutritional and exercise adaptation lists to this, but these guidelines should keep the majority of people objectively busy and actually healthy if you can achieve all of these.
Please comment on this blog or reach out to me directly if you have questions or would like help becoming a healthier person. Please stop focusing on achieving a normal BMI because that will not make you healthier.