On The Gist, dig into body mass index with our resident bulls—t debunker Maria Konnikova. Does a healthy BMI actually mean anything? The question came up after Donald Trump’s recent appearance on The Dr. Oz Show, in which his weight and height were revealed—if his numbers are to be believed, his BMI is 30.3, which qualifies as obese. But does BMI actually tell us anything meaningful about health? Or is it an arcane measurement that needs to be phased out?

Also, more on Tuesday’s testy vice presidential debate.

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