I was reading an article on the pdi this morning about how a certain a-list actress got her abs back without going to the gym. The article was an advertorial for a popular canned food company here in the Philippines so the premise of a gym-less program was expected. I have nothing against that, in fact I always say in my talks that a healthy and active lifestyle does not require a gym membership, as long as you stay active. The only problem I had was a statement about “normal” weight, made by the author: “the actress admitted that she was at her heaviest at 116 lbs. For a female who stands 5’5″ that’s normal weight.”
I knew for a fact that for a female, standing 5’5″, 116 pounds is too light. Even when you factor in frame size, it still is below the range for that height. I have no idea what led the author to write the statement but it got me thinking about ideal weight and the Body mass index, which is a guide to know your ideal weight compared to your height. The way to compute for BMI is by getting the square of your height in meters and then dividing your weight in kilograms with that number.
In my case, I weigh 80kg and my height is 5’9″. 5’9″ is 175.26 centimetres or 1.75 meters. So to get my BMI:
80 kg / (1.75 x 1.75) = 80 kg / 3.1 = 25.8
What exactly does that mean? Well the normal range for BMI is from 18.5-25 so technically this puts me in the overweight category. I don’t mind cause with me in that category is Lebron James (6’8″ 225lbs), Gerald Butler (6’2″ 190lbs) and if you’re into Crossfit, Rich Froning (5’9″ 195lbs).
The point is, even if these guys are technically overweight, these are individuals who are arguably at the top of their fields and are awesome performers. Sure they’re overweight in the standards of BMI but I wouldn’t call them unhealthy or unfit.
Therein lies the problem of BMI as a scale: it doesn’t consider your body fat percentage, something that is much more important and is a greater risk factor than body weight. In my example, even though I have a BMI that is considered overweight, my 11.5% body fat says that I’m fine. The same could be said for the other people I mentioned. Even with overweight or obese level BMI’s, with low body fats and high levels of muscle, it negates the BMI rating. Weight training does that. So if you do a lot of weight training, you can expect your muscle weight to go up which means your body weight will also increase. Don’t worry. As long as you keep your body fat low, you should be fine.
Nowadays, I only use BMI when I’m dealing with overweight or obese-level clients who also have high levels of body fat. I will also, always consider the body frame which can be easily measured by getting the circumference of your wrist. And I always use it along with body fat. I also use it for people who for one reason or another, will not or can not weight train. Since I promote weight training (because it’s good for you, really you should try it, especially you, ladies), I almost always never use it anymore. Hospitals will keep on using BMI though so on your next check up, make sure to inform your physician if you weight train (but more likely, he will notice it when he sees you). Instead, I use the body fat scale that you can see below and I aim for fat loss, rather than weight loss.
This chart takes into account age and sex since your body fat will increase with age and females tend to have more body fat for biological purposes. I suggest you use this instead of worrying about your BMI.