Sandwiches – such as a basic peanut butter and jelly between two slices of Wonder Bread – were the single biggest item eaten in 1996 by Americans, both at home and on the road.

Ten years later sandwiches have broadened into wraps, submarines and panini, but remain the No. 1 food item.

And food experts say sandwiches almost certainly will remain in the top 10 food items being eaten, if not the top item, in 2016.

To maintain their dominance, sandwiches will continue to evolve. For example, sandwiches aren’t just being eaten at lunch.

They are now the most-eaten item at breakfast – remember that Egg McMuffin you had for breakfast – and could quickly emerge as the most-sought item for dinner.

It’s a trend that sandwich chains ranging from Panera Bread to locally owned Potbelly Sandwich Works are hoping to exploit with their hot sandwiches.

“We’re introducing entree salads that we think will help balance our sandwiches at dinner,” said Bryant Keil, Potbelly’s chairman and chief executive, noting that the Chicago-based chain has fared well in the past during the dinner hour.

Sandwiches are now a $121 billion market, of which 45 percent comes from sales at burger restaurants like McDonald’s, Burger King and Wendy’s, according to data compiled by the Packaged Facts market research firm.

“Any way that someone can do something new with sandwiches is a good idea,” said Harry Balzer, executive vice president of the NPD Group, a worldwide sales and market information company that focuses heavily on food.

Don Montuori, publisher of Packaged Facts, said the introduction of paninis and international flavors have given delis and convenience stores the chance to “raise sandwiches to a new art form.”

Sandwiches have been a mainstay of the American dinner for 20 years, but in the past decade there has been a shift toward hot sandwiches aimed at filling the desire for a hot meal.

Twenty years ago, 5.3 percent of all dinners included a cold sandwich, while 7.9 percent included a hot sandwich, according to the NPD data. This year, cold sandwiches account for only 4.4 percent of the dinner-hour meal, while hot sandwiches now total 8.9 percent of the meals.

Balzer said one of the biggest shifts in meal patterns has come at the expense of beef. No longer are people asking: “Where’s the beef?”

Two decades ago, beef was included in 17.3 percent of all meals served at dinner. That has now dropped to 9.7 percent of all meals served at dinner and the falloff shows no signs of stopping, he said.

Beef has been replaced by chicken, which climbed to being included in 12.6 percent of all meals from 8.9 percent, and also by the one thing that parents have found they have no trouble getting their kids to eat – pizza.

It doesn’t make any difference whether it is frozen pizza baked at home or a pizza ordered in, according to Balzer.

The popularity of pizza has doubled during the past 20 years to now being included in 6 percent of dinnertime meals, up from 3 percent.

A shift to higher consumption of sandwiches has an upside for many companies, but can turn into something to be contended with by others who produce dinner-type meals.

James Jenness, chairman and chief executive of Kellogg Co., said that food companies can overcome that kind of shift.

“Companies that excel with strong innovation based on better meeting consumer needs and enhancing their brand portfolios will win in the marketplace,” he said.

Kellogg, for instance, is gearing up to introduce a number of new products designed to tap consumer needs ranging from speed to taste.

Speed will come with two varieties of nutrition bars, while a new variety of Special K aimed at chocoholics is taking aim at the taste category, he said.

However, one of the largest emerging trends, he said, will be the effort of food companies to target the 60-and-older population, which is expanding rapidly.

Estimates are that the percentage of the global population that is age 60 or older will double from the current 11 percent in a little more than 40 years.

“This trend presents a ‘big time’ opportunity to leverage product choices that address this population’s needs, including heart health, digestive health and shape management,” Jenness said.