In response, last month FreshDirect introduced a line of dinner kits that demand some cooking: chicken breasts premarinated in yogurt, but not cooked, delivered along with pattypan squash and zucchini already cut and peeled, ready for the oven.

Ordering a kit isn’t as thrifty as cooking from scratch; the meals cost $7 to about $17.50 a serving, more than it would cost to buy the raw ingredients at FreshDirect or Whole Foods. But a precooked version of a similar dish from Schwan’s would also cost about $6 a serving; from Boston Market, about $8.50.

The companies say the kits can save money by reducing food waste, since all ingredients are used up; there is no need, say, to buy a jar of curry powder when only half a teaspoon is called for. And, they say, given the quality of the ingredients and inventiveness of the recipes, the proper price comparison to make is with a restaurant meal — at the kind of restaurant that their target audience prefers: sophisticated, with a global, seasonal or local spin.

The dinner-kit business model — online ordering, overnight shipping, premium ingredients and weekly recipes — has already proved successful abroad. The first service, Middagsfrid, started in Sweden in 2007, and the concept was quickly replicated elsewhere in Europe.

So far, it has been a niche enterprise for young urbanites, but that niche is clearly growing, with copycats around the globe. HelloFresh, owned by the German e-commerce giant Rocket Internet, delivers more than 10,000 boxes a week in Germany, the Netherlands, the United Kingdom and Australia, and has expanded its reach in the United States from Maine to Florida. (Dinner kits are now available mainly along the East Coast; HelloFresh distributes as far west as Wisconsin, and the company has plans to go national.)

In this country, there have been few new models for e-commerce in fresh food since online grocery shopping became popular. Perishable ingredients, unlike boots and best sellers, remain bound to brick-and-mortar markets. “Food is one of the last pieces of daily life that is still analog,” said Mr. Hix, of Plated. “We want to bring it into the digital space.”