![\"reddit_before_after\"](\"http:\/\/www.decisionsciencenews.com\/wp-content\/uploads\/2014\/11\/reddit_before_after.png\")
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Click to enlarge\n<\/p>\n
How many pounds do you need to lose in order to reduce your waistline by one inch? How many kilos do you need to lose to reduce your waistline by one centimeter?<\/p>\n
We wanted to find out. We were having trouble finding published data (though we are expecting some soon), so we turned to Reddit<\/a>, where the progresspics<\/a> subreddit contains people’s before-and-after weight change stories. Most posts contain only pictures, but if you do some web scraping, you can find cases in which people post their before-and-after waist measurements.<\/p>\n We found 46 such cases, typed them up, ran them through R<\/a>, tidyr<\/a>, dplyr<\/a>, and ggplot<\/a> and made the picture above.<\/p>\n Multiple regression tells us that on average, for every 8.5 pounds lost, people dropped an inch off their waist. (And for every 1.5 kilograms lost, people dropped a centimeter off their waist.)<\/p>\n Every 10 pounds lost was accompanied by 1.18 inches of waistline reduction. (Every 5 kg lost was accompanied by 3.33 cm of waistline reduction.) Want to see the data split out by gender? Voila:<\/p>\n \n Want to make this graph yourself? OK.<\/p>\n
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\nThe picture is a bit rosier if you are losing under 55 pounds (25kg): You only have to lose 6.1 pounds to lose an inch (or 1.1 kg to lose a centimeter).<\/strong><\/p>\n<\/a>
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Click to enlarge\n<\/p>\n