KANSAS CITY — Kale recently claimed a spot on McDonald’s menu as an ingredient in a line of high-protein breakfast bowls the chain began testing in Southern California restaurants. One bowl features turkey sausage, egg whites, kale, spinach, bruschetta and cheddar jack cheese. Another includes chorizo and egg on a hash brown with shredded cheddar jack cheese and pico de gallo.

The items underscore a larger trend in the restaurant industry. Bowls are booming.

Counter to increased demand for handheld and sippable meals, a number of national chains have favored the format in recent launches. Earlier this year, Panera Bread introduced a line of broth bowls, including a soba noodle bowl with chicken and a lentil quinoa bowl. KFC rolled out a line of rice bowls in spicy barbecue and Tex-Mex varieties for a limited time. And Noodles & Co. unveiled its Buff Bowls, which substitute spinach for the fast-casual chain’s typical pasta and double the vegetables. Varieties include Japanese Pan with marinated steak, Tuscan Fresca with grilled chicken breast, Bangkok Curry with organic tofu, and Pesto with pork.

What’s so super about bowls?

“Customization is a growing trend, and many bowl options allow consumers to pick and choose the ingredients,” said Kelly Weikel, director of consumer insights for Technomic Inc., Chicago. “Bowls also allow consumers to try new ingredients without ordering a completely foreign dish. The ability to add a new ingredient to a familiar bowl of food is a great way for a consumer to experiment without leaving their comfort zone.”

Fresh Mex bowls at Chili’s Bar & Grill, for example, offer a choice of grilled chicken, pork carnitas, seared shrimp or grilled steak, plus house-made corn, black bean salsa and pico de gallo, chopped cilantro, sliced avocado, rice, field greens, and tortilla strips, plus chipotle pesto and cumin-lime sour cream or margarita sauce.

Consumers may also view bowls as a healthy, creative and more filling alternative to salads and soups, Ms. Weikel said. A bowl containing the deconstructed ingredients of a sandwich or burrito may be perceived as a better-for-you option with fewer carbs and calories. On the Border has unveiled a new line of Border Bowls, prepared-to-order dishes made with cilantro lime rice, black beans, bell peppers, queso fresco, lettuce, pico de gallo and avocado.

Bowls also cross day parts. The breakfast menu at First Watch includes a pair of Power Bowls, which combine quinoa with chicken breast, roasted vegetables and fresh herbs.

The Energy Bowls at Jamba Juice swap the straw for a spoon. The Acai Primo Bowl combines acai juice, soymilk, blueberries, strawberries and bananas, topped with organic granola, fresh bananas and blueberries, coconut and a drizzle of honey. The Chunky Strawberry Bowl contains a blend of Greek yogurt and strawberries, bananas, peanut butter and soymilk, all topped with organic granola, bananas and strawberries. The Fruit and Greek Yogurt Bowl features nonfat Greek yogurt topped with fresh blueberries, strawberries and bananas, organic granola and a drizzle of honey.

Click for a slideshow of bowls offered at restaurant chains.