Why now would sitting in school contribute to obesity in children?

More complicated: Kids have been sitting in school for centuries. Pediatric obesity is a much more recent phenomenon. From an activity standpoint, kids are sitting more in general: in front of tv, computers, video games. Less physical activity including less pe in school. Of greater devastation is our diet in this country which has become higher in calories overall, mostly contributed to by bad fats & refined carb.

Many reasons: one reason I can think of is less gym time, Some schools offer other classes in place of what was gym time Another reason can be poor food choices in the cafeteria. Many schools offer hamburgers, franks, pizza with fries as healthy lunches. It is more convenient for the school but less healthy for the children- Including chicken nuggets that are deep fried.

Kids are active.: At least they used to be. After school, kids used to get home, have a snack, do their homework then play outside for hours, burning calories and counterbalancing the sedentary school day. Nowadays, they come home, have a snack, do homework, text, FaceTime, play video games, watch TV, eat eat eat. THAT contributes to childhood obesity.