This. I think it must actually take dedication to eating like this everyday to actually do it. They've just been doing it for so long that they have stretched their stomachs out until it feels like normal to them.  I overindulged on some fajitas a few weeks ago (absolutely no cheese and I didn't even go over my calories for the day but I usually go a little under) and felt terrible for about a day and a half. I don't want to imagine how sick I would have been had I eaten a bunch of cheese too so I know you must be truly miserable. Well, that cured my craving for Mexican food for quite a while.