There's one topic that NPD Group's food and beverage industry analyst Darren Seifer has been getting more calls about than any other: meal kit delivery services such as Blue Apron and HelloFresh.

"It's the biggest thing I get asked about from reporters these days," Seifer told IntraFish.

Still, even with all the buzz, the services -- which provide all the necessary ingredients to prepare a meal, as well as detailed instructions on how to prepare the food -- the niche sector has been slow to grow so far.