Pretty sure it is a joke in response to bullshit articles like this from 2014 or this from 2012.  More recently, the joke was made because of a post on PoF, which states   I think it would be a good idea to put 'a few extra pounds' when their BMI is hitting between 30-35ish, depending on how the individual feels and looks. It's best to not be misleading though. Then BBW for 35+ bmi