When it comes to issues like obesity, with its myriad contextual factors underpinning the causes, it is very useful to look at trustworthy numbers that tell us how much a population-wide intervention is going to cost, how well it’s going to work, and whether or not we’ll end up “in front” so to speak.
This table, from one of a series of Lancet articles on obesity and its cost to society, spells it out quite clearly.
Professor Adam G. Dunn 