In September, Mark Bittman, the well-known food writer, authored his last column for the the New York Times. After five years covering food issues as a columnist for the paper, he was leaving to embark on a new and undisclosed adventure. "I see it as putting philosophy into action," he wrote, sharing only that he was joining a start-up that encourages people to eat more plants, and that more information would follow.

Now the details have emerged.

On Monday, Purple Carrot, a vegan meal kit delivery service, which ships pre-measured ingredients and recipes, announced that Bittman has joined full-time as partner and chief innovation officer. The company's mission —  centered around the value of a plant-based diet — is closely related to what Bittman has advocated for for years.

"There was never a grand plan to be a cookbook writer, and then a food writer, and then a columnist, and then an entrepreneur," Bittman said in an interview. "But this really allows me to do things in a different way, to advocate for what I have been writing about in a new way."

"This is about getting more plant-based foods into the hands of people," he added.

Bittman's role will include creating the recipes Purple Carrot offers each week — thus far, he said, he has spent a lot of time in the kitchen, developing menus and working with other cooks. It will also entail writing for the company's new Web site, which he helped develop, and other less-well-defined responsibilities, such as advocating for plant-based eating and pushing the food industry toward more sustainable packaging and sourcing.

"I think we'll pretty quickly figure out where my strengths lie," Bittman said. "Presumably, though, this will all at least mean better food."

Bittman is not a vegetarian or a vegan, but he has been a longtime advocate of plant-based diets, which he argues are better for both the health of people and of the world. His 2013 book Eat Vegan Before 6 makes the case for adopting a predominantly vegetable- and fruit-dominated diet, and he has a corresponding cookbook with recipes to try. Still, some have criticized Bittman for touting veganism without adhering to it, saying that he doesn't go far enough.

The meal kit delivery industry has capitalized on the public's demand for convenience and its newfound interest in cooking. Instead of selling prepared food or providing a recipe to follow, these businesses, such as Blue Apron and Hello Fresh, deliver to a customer's doorstep a combination — all the ingredients someone needs to make a dish, carefully portioned out and neatly packed, along with easy-to-follow instructions. The concept has proved popular, attracting tens of millions of dollars in venture capital funding. The market is on pace to become a $3 billion to $5 billion industry over the next 10 years, according to market research firm Technomic.

For Purple Carrot, partnering with Bittman means a boost to the brand's visibility, an important asset given how much ground it has to make up for. So far, the one-year-old company has raised $1 million, and is in the process of securing another $3 million.

Blue Apron and Plated, two of the largest U.S. meal kit delivery services, meanwhile, have raised nearly $60 million and $22 million, respectively, since they were founded in 2012. And HelloFresh, which is based in Europe, has raised almost $200 million, and hopes to increase its presence in the U.S. Those services offer both meat and vegetarian options, but not vegan only options (meaning no animal products whatsoever.)

Bittman first met Andrew Levitt, founder and chief executive of the Purple Carrot, earlier this year in Boston, where the company is based. They hit it off and kept in contact, but Bittman says he never felt pressured to make a decision. "I said to Andy, why don't we just play around with commitments, take out time, so I can evaluate things pretty calmly," he said. "We did that for a few months, and then it become clear to me that this was right."

Along with the addition of Bittman, Purple Carrot announced that it is expanding to the West Coast, which will allow it to serve an estimated 70 percent of the country. It will also begin offering meal kits for two people, instead of the four it has offered in the past. Customers can subscribe to receive two or three meals a week.

The company doesn't share how many customers it currently has, but Bittman said that it has been shipping out roughly one thousand boxes per week over the last few months.

"With the news of me joining, and the whole expansion, it's not inconceivable that we could be shipping twice as many by next week," he said.