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. Panoply survey We want you to tell us about the podcasts you enjoy and how often you listen to them. So we created a survey that takes just a couple of minutes to complete. If you fill it out, you'll help Panoply to make great podcasts about the things you love—and things you didn't even know you loved. To fill out the survey, just go to megaphone.fm/survey. Today's sponsors: Get quality shaving products delivered right to your door with Harry's. Sign up for a shave plan at Harrys.com and use promo code gist at checkout to claim your Free Trial Set and post-shave balm. iBooks is the place to find the books that people are talking about right now, including Born to Run, Bruce Springsteen's memoir. It's a mix of beautiful nostalgia and straight talk about family, fame, and music. Get it on apple.co/brucespringsteen, where you'll find all his music too. Join Slate Plus! Members get bonus segments, exclusive member-only podcasts, and more. Sign up for a free trial today at slate.com/gistplus.  Learn more about your ad choices. Visit podcastchoices.com/adchoices