# Over one third of Americans are obese. Just how overweight are we, collectively?

Short answer: Americans are about 5.7 billion lbs overweight. This is more than the combined mass of every Nimitz-class aircraft carrier ever built.

Long answer: Obese and overweight mean two different things, but they’re both determined using the “Body Mass Index” – better known as the BMI. The BMI is a number calculated using a person’s height and weight and is used to classify that person into a category of underweight, normal weight, overweight, and obese. A normal BMI is 18.5-25, and overweight BMIs are 25-30. Anything above 30 is considered obese.

You can calculate yours by dividing your mass in kilograms by your height in meters squared, or you can just find where you live on this pretty plot:

Many people are critical of the BMI because the categories are arbitrary, and it doesn’t account for individual variation. For example, two people could both be 6 feet tall and weigh 225 lbs, but one could be a professional athlete while the other could be an amateur Doritos/Mountain Dew taste tester. Because they have the same height and weight, both of these people will have a BMI of 30.5, which is just over the threshold for obesity, but I think we all know which of the two is healthier. Despite these limitations, the BMI is a popular tool for tracking populations because it’s easy to use.

According to the CDC, more than two thirds of American adults [1] – and nearly a third of children [2] – are overweight or obese.

If two thirds of adults are overweight then, statistically speaking, does this mean a normal weight makes an adult a minority? Image from AHealthBlog.

But how overweight are we, collectively? Let’s calculate how overweight the average American is, and scale things up from there. The CDC tells me that average American man is 5′ 9″ and 196 lbs, while the average American woman is 5’4″ and 166 lbs [3], having respective BMIs of 28.6 and 28.7. The upper limit for a healthy weight for a 5’9″ person is 169 lbs, and it’s 146 lbs for a 5’4″ person. Therefore, our average man needs to lose 27 lbs to get down to a normal BMI of 25, while our average woman needs to lose 20 lbs. With a population of about 320 million, but excluding people under 18, we find an adult population of about 245 million, where 50.8% are women [4]. All together, I calculate that America is collectively 5.7 billion lbs overweight [5].

As is tradition, we need to put big numbers in perspective. A Nimitz-class aircraft carrier, fully loaded, weighs almost exactly 100,000 tonnes. If America was a guy, his excess mass would outweigh all ten of the U.S. Navy’s largest warships combined.

If we attempted to lose these 5.7 billion lbs, we would have to burn 20 trillion calories of fat-stored energy. This is enough energy to fuel Michael Phelps, at peak Olympic training needs, for nearly 7 million years. Or perhaps more relatably, this is also enough energy to power the entire US for a year. If congress wants a green energy policy, I’d recommend investing in over-sized hamster wheel manufacturing.

“The House will now hear Bill 15-085, ‘A Modest Proposal to Power Our Aircraft Carriers with Fat Guys on Giant Hamster Wheels.’ Congressman, you have the floor.”

Honestly, this policy would kill two birds with one stone, reducing both energy and healthcare costs. Estimates put the cost of obesity related healthcare near \$150 billion each year [6], and it’s only going to go up with the rate of obesity. Compare that to the \$4.5 billion price-tag on an aircraft carrier –  if we could lose this extra weight then with the money saved on healthcare we could afford to quadruple the number aircraft carriers in service… not that we’d want to though.

Have a question? Send it to matt@quarksandcoffee.com