CHICAGO — Downsized dishes are on an uptick.

More mainstream restaurants are adding tapas and tasting menus in an effort to accommodate an emerging style of dining popular among millennials: snacking, sampling and sharing.

Click here for a slideshow of recently introduced small plates at restaurant chains.

“Appetizers, small plates and accompaniments are becoming more of a draw,” said Darren Tristano, executive vice-president of Chicago-based research firm Technomic, Inc. “In fact, our data shows that consumer purchases of appetizers are steadily getting closer to pre-recession levels. That’s good news for operators looking to promote add-on sales of starters and other extras. Highlighting the shareable, fun factor of these foods — as well as their versatility — helps them function as menu differentiators.”

Among those who order small plates, a third eat them as a starter to the main meal, a third eat them as a main meal, 19% eat them as a side dish, and 14% eat them as a snack, according to  Technomic.

To hook those nibblers, Olive Garden recently introduced its Tastes of Italy menu, which features pared-down portions of grilled chicken spiedini, Parmesan roasted asparagus, fried pizza dough and crispy risotto bites. The launch followed a similar move by TGI Friday’s, which in April unveiled its Taste and Share menu, with ahi tuna crisps, hibachi skewers, Thai pork tacos, bacon macaroni and cheese bites, corned beef and Swiss cheese sliders, garlic and basil bruschetta and Parmesan meatballs. Also this year, Applebee’s introduced a Take Two promotion, allowing diners to mix and match small servings of signature entrees, such as blackened sirloin, garlic rosemary chicken pasta and lemon shrimp fettuccine. The grill and bar billed the deal as a solution to “food envy,” often experienced by millennial customers when dining out with friends, according to an Applebee’s-commissioned survey.

Serving a desire to sample multiple flavors was Outback Steakhouse’s aim with this year’s limited-time Steak Flights menu, which offered a combination of steak options with various sauces. The menu was designed to “allow guests to explore flavors on one plate without feeling locked in,” according to the company. Also launched for a limited-time was a dessert flight, featuring mix-and-match cake pop flavors.

Miniaturization has become a “menu must-have,” said restaurant trends expert Nancy Kruse during a Sept. 12 webinar presented by the National Restaurant Association.

“The small plates phenomenon… has been huge,” Ms. Kruse said. “For a customer who’s maybe a little bit unsure about (an item) and would like to give it a test run, these are nice small bites — controlled-portion, controlled-calorie, cost-controlled and really day part flexible, as well.”