I remember arriving at Los Angeles Airport after my first trip to europe from the u.s. in 1988. I was 46, late in getting to make such a trip. I remember blinking at the large numbers of chubby people in the then waiting area at LAX. I had been away a month to a country where there were some differences from us, and so was startled.
First of all, blaming is not my interest. I can see and agree with genetic and physiologic and metabolic reasons for obesity, some starting from birth with the number of fat cells and biochemistry already going strong. I understand the usual easy does it 'calories in exercise out' mode does not always work. I can see 'fat baby is healthy' cultural stuff. I can see the change in children's play, from when I was a kid, that happened for several reasons including fear of predators (media promoted or not), and women as a group getting jobs even, gasp, while being mothers. I was taught a woman could only be a doctor if she was single, and the mcat books in '62 reflected that as well sheer dominance bias. Things started to change just after that.) TV got ever more interesting and then came video games. TV as baby sitter. Families moving, so no easy care with relatives. I can see food companies supplying the wants of the multitudes, salty grease and sugar in revolving desires. I can strongly see need for inexpensive food.
This is all a culture, and we in the u.s. and some other places have been spreading it. Meantime we have another mode, making fun of France (etc), which we could learn from, or could have.