Delta will upgrade free snacks in the economy-fare cabin

If it's true that an army travels on its stomach, will better snacks keep passengers loyal to one airline?

Delta Air Lines is rolling out new free snacks for customers in the main cabin, including brand-name yogurt bars and pretzels. Some will come in larger portions than before because, Delta has figured out, that's what customers crave.

The menu move comes about a year after United Airlines brought back free snacks by offering noshes like stroopwafels -- a gooey Dutch confection -- and better coffee. Earlier this year, American Airlines restored free snacks on domestic flights.

Airline executives say they're focusing on both big and little things in the battle for customers.

Delta said Thursday that beginning next week it will retire the airline's brand of peanuts and pretzels and replace them on longer flights with Snyder's of Hanover pretzels, Squirrel honey-roasted peanuts and NatureBox yogurt bars.

Fans of the Biscoff cookies need not fret -- those are staying.

Delta also is testing free sandwiches and other meals in economy on some flights between New York and California.

For decades, air travelers took it for granted that they would be served meals as part of their ticket price. Airlines gradually took away that perk to save money, but came off looking Scrooge-like.

Continental Airlines claimed it would save $2.5 million by no longer giving away pretzels in 2011. That year parent United Continental Holdings Inc. earned $840 million.

Airlines today seem even more financially healthy enough to feed their customers: Atlanta-based Delta Air Lines Inc. earned $4.5 billion last year.