I'll admit I'm only saying anecdotes, but I've met very, very few obese people who said they ate when "bored or sad". The friends I had who did gain weight, did during the fat-free craze of the late 80s and early 90s, when "guilt-free" candybars shot onto the market labelled as diet foods. It even has a name: the "SnackWell Effect".

ref: https://en.wikipedia.org/wiki/Snackwell_effect