i didn't first eat doritoes b/c of advertising - i first ate them b/c i was at a party, and they were in a bowl, and they were tasty - later, when i was of age, and had cash, i would make that hard choice between nacho and ranch flavor, again not b/c of ads, but b/c i was hungry/bored/in 7-11/or simply b/c they were by the damn cash register when i was also buying a 50 cent pack of camels
your "obesity crisis" is a beast w/ many legs, only 1 of which would be ads. at any rate, this crisis is far less menacing then the true food shortage crises that once killed peasants by the thousands in endless cycles. it's hard to feel sympathy for folks who fucking eat themselves to death.
i like shakespeare's take on being portly, a line from merry old jack falstaff to his drinking buddy, young prince henry, who is afraid will neglect him when he becomes king:
". . .If sack (a drink made of wine and sugar) and sugar be a fault,
God help the wicked! if to be old and merry be a
sin, then many an old host that I know is damned: if
to be fat be to be hated, then Pharaoh's lean kine
are to be loved. No, my good lord; banish Peto,
banish Bardolph, banish Poins: but for sweet Jack
Falstaff, kind Jack Falstaff, true Jack Falstaff,
valiant Jack Falstaff, and therefore more valiant,
being, as he is, old Jack Falstaff, banish not him
thy Harry's company, banish not him thy Harry's
company: banish plump Jack, and banish all the world."
let plump jack be fat in peace, eh?