I saw this proposal on what I think is the campaign website for the Green Party candidate for Mayor of Paris. To read about it, you'll need to either know French or else trust the whims of Google's automatic translator, but the basic idea, as seen on the card, is to create a generous program along the lines of food stamps here in the U.S. but specifically targeted at the purchase of fresh produce.
In the developed world we're (fortunately) past the point where inability to afford an adequate quantity of calories is a series problem, but instead we've got a serious problem of people getting too fat while simultaneously not getting enough nutrition. This sort of targeted program could help, though so would altering our absurd health- and environment-destroying agricultural subsidies policies. We could even keep subsidizing agriculture to a ridiculous extent but just try to shift to subsidizing healthy stuff instead of corn, beet sugar, corn-bases sugar substitutes, etc.
I like these Paris transportation ideas too.