Today, virtually all food products in (US) grocery stores have UPC codes. You can use apps like MyFitnessPal and others to lookup the UPC code and get information (some of it from USDA, others crowd sourced).
This seems like the perfect place for a QR code on packaging, that contains all the nutrition information, ingredients, dietary/allergen compliance status (gluten, vegan, etc).
Where would a push for this kind of thing happen - from the food producers, or from a vendor or reseller of some kind? It makes tons of sense, but it seems to be a chicken/egg scenario.
http://www.fda.gov/Food/IngredientsPackagingLabeling/Labelin...
I think any requirement for this would have to come from them. Of course there's probably a grocery industry group that would also have the power to get something like this set up if it were somehow desired or otherwise profitable.