NEW YORK — Special K was once just a line of cereals. Today, it’s a diet food empire.
The brand first hit shelves in 1955 as a no-frills breakfast alternative but now caters to dieters who see its airy chips and pastries as a way to beat cravings and lose weight. And this summer, Kellogg Co. is building on its biggest moneymaker with a ‘‘hot cereal’’ called Special K Nourish that’s made with quinoa and other grains.
The new line, which promises to fill people up with 8 grams of protein and 5 grams of fiber, reflects Special K’s push to move in step with evolving trends. Until now, Special K products largely gave dieters low-calorie imitations of their fantasy foods. But weight watchers are increasingly looking for added nutritional benefits, rather than just counting calories.
‘‘They’re eating better, not just eating less,’’ said Noel Geoffroy, vice president of marketing for Kellogg Morning Foods.
The Special K Nourish hot cereal will come in individual serving cups; people add water and toppings that come in separate compartments on the lids. The products, which have less than 200 calories, are slated to hit stores in July and will come in Maple Brown Sugar, Cranberry Almond, and Cinnamon Raisin Pecan. A line of Nourish bars will come in Dark Chocolate Nut, Cranberry Bliss, and Lemon Twist.
Special K’s evolution to stay relevant is critical for Kellogg. The company, which also makes Frosted Flakes and Eggo waffles, has been struggling to grow cereal sales at a time when Americans are looking for more on-the-go options. Over the past decade, for example, sales of cold cereals in the United States have grown just 6 percent to $8.9 billion, according to the market researcher Euromonitor International.
But Special K has been standout for Kellogg, with the brand’s market share increasing to 5 percent, up from 3.3 percent a decade ago, according to Euromonitor.
The broader transformation of Special K into a weight management tool also reflects its ‘‘Special K Challenge’’ ad campaign that first aired in 2003. Those ads famously promised that women would be able to lose 6 pounds in two weeks by replacing breakfast and lunch with Special K and having a sensible dinner at night.
‘‘It really hit on the need women had for easy, attainable way to manage their weight,’’ Geoffroy said.
The Special K brand became a psychological stamp of approval and Kellogg has been churning out spinoff products ever since. Shakes and bars came in 2006, cracker chips in 2009, and popcorn chips last year. Three types of breakfast sandwiches popped up in frozen food sections in January.