I would encourage you to revise your summary. We don't know what the third-order drivers of obesity are, but we absolutely know that caloric surplus is the prim

I would encourage you to revise your summary. We don't know what the third-order drivers of obesity are, but we absolutely know that caloric surplus is the primary driver, and that surplus is driven by both lower energy expenditure (sedentary lifestyle) and increased caloric intake (junk food). There are other causes for individuals, but not at a population level. The question is much more: why did people start moving less & eating more? Each have complex factors (less physical jobs, increased wealth, food addictiveness, cultural shifts, etc.), and on THOSE, there's lots of debate. But we absolutely know what causes obesity at a population level.