NEW YORK — Whole Foods is getting ready to launch its first national marketing campaign and expand home delivery as it looks to fend off bigger players muscling into the organic and natural foods category.

The company, based in Austin, Texas, said the marketing campaign this fall will explain to customers what makes it different and why it’s better than other supermarkets.

“We believe there are real and substantive differences in the company and in the values and the foods that we sell,” said Walter Robb, co-CEO of Whole Foods.

In addition, he said the company will partner with third parties to offer home delivery in 12 to 15 major markets, with plans for a wider rollout over time. Whole Foods declined to give details about which cities will get home delivery, but it already offers delivery in select markets, including New York City.

In coming weeks, Whole Foods also said it will test a new loyalty program, with plans to roll it out widely in time for the winter holidays next year.

The efforts come as Whole Foods struggles to spark slowing sales growth, which has worried investors that the company is losing ground in a segment it once dominated.