Yea, here in the U.S we have a big problem with obesity. You can blame it on a lot of things but it is a combination of diet and lack of exercise.
This country has this deal with working 40+ hours a week so people are too tired to exercise and all. They also, well, not all but a lot of them eat like shit. Eating breakfast, lunch AND dinner at Mcdonald's everyday will get you in trouble.
I am 5'8 and weigh about 170. I have a thin build but I do have to watch what I eat. I mean, I do not eat "out" often, maybe once a month I will score up a big ol' double cheeseburger, tater tots and a soda. I do not eat a lot of ice cream or chips so, I TRY to eat healthy.
The girl in the video? That's definitely some sort of health disorder. Maybe a glandular problem?
Oh yea, just to add, my ex had gastric bypass years ago. Crazy ass operation. Not for the timid. She was heavy most of her life and just, well, could not take it anymore. She had a lot of complications but she lost weight rapidly.