For Millennials, convenience tops the grocery list

Members of the millennial generation, born between 1981 and 1996, are less likely to go to the grocery store than Baby Boomers or Gen X-ers and spend less per person when they do go to the store, write two USDA economists. "Millennials are demanding healthier and fresher food — including fruits and vegetables — when making food-at-home purchases, and they place a higher preference on convenience than to other generations."

Who buys groceries online? Nine percent of adults in a month.

When Amazon announced its deal to buy Whole Foods, the instant analysis was that groceries would be the next big thing in online shopping. If so, there is a lot of room for growth since a sliver of Americans – 9 percent, according to Gallup – say they order groceries by Internet at least once a month. The number of regular shoppers is smaller still: 4 percent of adults order groceries online once a week or more often. By comparison, 83 percent said someone in the family goes to the store at least once a week, according to a Gallup survey conducted by phone in early July.