You might be surprised who the government considers too fat, too skinny, and just right.
When Furious 7 set box-office records on its opening weekend, there was one story lurking in the shadows of the celebrity-industrial complex that no one wanted to talk about: The star, Vin Diesel, is overweight.
And costar Dwayne Johnson? Dude’s obese. Johnson has a body-mass index, or BMI, of 34.3. Which means, according to U.S. government standards, the Rock is obese. And Diesel, at 27.1, is overweight.*
If Johnson and Diesel aren’t the first guys you think of when you ponder America’s obesity problem, you begin to understand the problem with using BMI, a ratio of weight to height, as a tool to judge an individual’s fitness or health risks.
And yet, BMI appears in the news with disturbing regularity. The French National Assembly recently passed a ban on hiring models with a BMI below 18. (A model who’s 5-foot-8 would fall just below the cutoff at 118 pounds, but she’d be catwalk-legal at 119.)
And in Belton, Missouri, a parent cried foul when her 7-year-old daughter came home from school with a note saying the child was overweight, based on her BMI.
Every article you’ve read about the obesity epidemic relies on BMI to tell us who’s too fat, and who’s just right.
BMI is indeed a terrible way to assess whether you’re lean or fat. But not for the reason you think.
What we now call body-mass index dates back to 1832, when a Belgian mathematician named Adolphe Quetelet observed that human weight “increases as a square of the height,” except during infancy and the adolescent growth spurt.
The focus on obesity and its complications for human health began with the insurance industry in the early 20th century. Specifically, it started with the company we now know as MetLife, sponsor of those Peanuts specials many of us watched as kids.
They published their first set of weight-for-height tables in 1942, and then updated it in 1959. The U.S. government started using BMI in 1980 to establish cutoffs for what was variously described as “ideal,” “desirable,” “suggested,” or “acceptable” weight.
Originally, both the insurance industry and the government recognized something we all understand by virtue of basic biology and common sense: Humans come in two genders, several body types, and countless ethnicities. Each has a slightly different distribution of height and weight.
If you happen to reach middle age, you also understand that weight naturally increases over the years. It takes a lot of effort just to keep the gain to a minimum, and few of us have the time, energy, or genes to maintain the same weight through life. Read more…