This is a long long trend, and the lines have already crossed, as early as December 2014. Note that some of these measures also include bars, and the trend is partly driven by people buying groceries at alternative retail locations (drug stores, convenience stores, etc.).

What's really interesting to me is that the Great Recession didn't have much of a long-term impact on this trend. Instead, the driving trend is that people, especially younger people, are living life like they're European urbanites, eating every meal at a cafe and cooking at home only for a special treat. (For some reason this makes Americans get fatter, but not Europeans. Maybe it's the difference between a Big Mac and a baguette.)