Next time you read 'obesity causes x' try to read 'chronic stress causes x' and see if it'll still make sense.
My guess is that it will make more sense. A body shape doesn't cause a lot of issues, but chronic stress might. Keep in mind that in the current culture, everybody with an obese body type is subjected to stigma and prejedice, from strangers, family members, (potential) employers, landlords, doctors, etc. Often also from themselves as well.

