CHICAGO — Attitudes about snack foods have undergone a metamorphosis. Once considered guilty pleasures, snack foods have become eating occasion solutions for a nation of on-the-go consumers, according to The NPD Group’s “Future of Snacking” report.

“Snack foods continue to evolve both as between-meal snacks and as part of main meals,” said David Portalatin, food industry adviser for NPD. “Each of these snack food roles is changing in different ways in reaction to Americans’ desire for balance, portable snack foods and holistic wellness.”

Americans consumed nearly 386 billion ready-to-eat snack foods last year, NPD said, with the majority of those eaten between main meals. As this trend continues to grow, snack manufacturers seeking success will need to meet four snack food needs that are forecast to grow: wellness, such as snacks with more protein; portability, such as single-serve snacks; and uniqueness, such as uncommon flavor mashups.

While wellness is trending, indulgent snack foods also are staging a comeback by walking the line between health and enjoyment, NPD said. Low-calorie, high-protein ice cream varieties and thinner versions of cookies are on the rise.

Additionally, consumers’ snack food choices are not limited strictly to flavor, NPD said. They also seek a unique experience. Emerging attributes for snacks include sensory elements such as texture, heat and aromatics.

“Snacking is no longer just about eating when you’re bored or eating for additional sustenance,” Mr.  Portalatin said. “Today and in the future, snacking is about solving small problems for consumers, and those problems present opportunities for food marketers across a variety of dayparts and needs.”