Snackers looking for a healthy bite on the go may need to read Kind snack bars’ nutrition information a little more closely.

At least four of Kind’s self-proclaimed healthy bars are in violation of “healthy” labeling requirements, according to the Food and Drug Administration, which sent a warning letter to the company.

“Your products do not meet the requirements for use of the nutrient content claim ‘healthy’ on a food label,” William Correll, director of the Center for Food Safety and Applied Nutrition, said in the letter, dated March 17 and released publicly on Tuesday. “You should take prompt action to correct the violations.”

The U.S. regulatory agency said the Kind bars -- Fruit & Nut Almond & Apricot, Fruit & Nut Almond & Coconut, Plus Peanut Butter Dark Chocolate + Protein and Fruit & Nut Dark Chocolate Cherry Cashew -- have too much saturated fat to be considered healthy.

The FDA standard is less than 1 gram, while the dried fruit and almond bar contains 3.5 grams.

Closely held Kind said it has officially responded to the FDA since receiving the letter.

“Nuts, key ingredients in many of our snacks and one of the things that make fans love our bars, contain nutritious fats that exceed the amount allowed under the FDA’s standard,” Joe Cohen, a spokesman for the company, said in a statement. “There is an overwhelming body of scientific evidence supporting that nuts are wholesome, nutritious and healthful.”
Surging Sales

Kind has seen its sales surge in recent years as Americans have moved toward savory snacks and demanded better ingredients.

Kind products are now in 150,000 retail stores in the U.S. The company sold 458 million units in 2014, more than tripling over the last two years, according to Daniel Lubetzky, the company’s chief executive officer.

Kind can’t use the term “plus” to describe the Kind Plus Peanut Butter Dark Chocolate + Protein bar because it doesn’t contain enough protein, Correll said.

The bars’ labeling also can’t include statements like “good source of fiber” or “no trans fats.”

The FDA said it may order the snack bars removed from grocery store shelves or seek a court order if the company doesn’t fix the labeling violations.