This Illustration Shows Why BMI Can Be A Poor Indicator Of Health

This Illustration Shows Why BMI Can Be A Poor Indicator Of Health
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BMI is a commonly used metric that’s supposed to tell you if you’re at a healthy weight or not. As this illustration created from scans of real people shows, however, BMI can be very misleading.

The six people in the illustration are all 5 feet 9 inches (175cm) tall and weigh 172 pounds (78kg), which means they have the same BMI or body mass index (calculated by dividing your weight by your height). Technically each would be considered overweight based on their BMI of 25.4, but some obviously appear more fit than the ones with more abdominal fat, which has been linked to increased risk of health problems.

As we’ve mentioned before, BMI can be misleading. The New York Times explains that since BMI only factors in height and weight, it doesn’t account for muscle or bone density and where a person carries weight.

BMI can be a useful measurement if it goes above 30, the threshhold for obesity, but overall, body fat percentage and body composition are more important health indicators than weight alone.

Same B.M.I., Very Different Beach Body [The New York Times]


  • Every single one of those 3D scanned individuals has enough body fat to make visible love handles (approx 15% or higher). This is hardly a wide range of body types. “Let’s start with the guy who is just over the threshold of a fit body and get everyone fatter than that for our scans.”
    The truth is BMI is a great indicator of health to the 95% percentile human, which is exactly why doctors use it (apart from it being easy to calculate without tedious functions and tape measurements). Just because some people gain significant amounts of muscle tissue which is not factored into the BMI calc doesn’t mean that BMI is a bad tool. It means that those individuals have placed themselves outside of the population BMI is considered useful for.

    TL:DR: If you haven’t gone to the gym regularly for at least 12 months and done a serious lifting program AT THE VERY LEAST. BMI is a tool you should be using.

    • Unfortunately the BMI fetish leads medical practitioners to completely disregard what’s in front of their eyes. When I’ve had checkups I’ve had ridiculous conversations with doctors who want to treat my BMI rather than my body.

      I haven’t done any weight lifting as exercise in more than a decade, but I am love-handle-free 30+ BMI, in part by being quite big-boned.

      Recently I volunteered to be a “patient” for a cohort of students who took a series of measurements for a mid-year exam. It was slightly hilarious having them calculate my BMI and see it conflict with what they saw when they used a measuring tape and 60% of them try to parrot responses based on BMI ranges. The examiner said to me later that it was good for them to see how reality diverges from such simple numbers.

        • The problem is with what you mean by ‘big boned’. I have quite wide shoulders and chest compared to most people. I’m not saying my bones are ‘bigger’, but they are demonstrable longer than someone with narrow shoulders/chest. Add in the extra muscle and connective tissue and it will make a difference – I’m not sure how much, but a difference nonetheless.

          According to the BMI, my ideal body weight starts at 60kg. When I was a starving uni student many years ago, I actually got down to 62kg – I looked like a concentration camp inmate (I was actually told that). If my weight goes below 80kg, I start to look gaunt.

          Also, I see no need that your reply should be so rude to the OP. You may think that he/she is a “fat activist” and “batshit insane”, but you sir, are a dick.

        • You read like a troll. I have not yet known a single troll who wasn’t batshit insane.

    • It seems a fairly diverse range of body shapes given that they’re all the same weight and height.

    • I think your statement is a little bit too literal.

      there are other forms of exercise outside of the gym and especially outside of weights, most people don’t realise the amount of exercise they do from having an active job or cleaning a lot.

      Heavy/serious lifting programs are not the only way to build muscle they never have and they never will be, every ones body is different and reacts in different ways.

      BMI is seriously generalised it may be a good “indicator” for issues but it should be used according to it’s ability as opposed to cancelling out more thorough techniques.

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