WASHINGTON — Senator Kristen Gillibrand and Representative Richard Hanna, both of New York, have called on the U.S. Department of Agriculture in a letter to reclassify Greek yogurt as a source of protein under the agency’s nutrition guidelines. Such a reclassification would make Greek yogurt eligible for inclusion as a source of protein in the National School Breakfast and National School Lunch programs to compete with other classified proteins, such as meats, poultry, eggs, nuts, seeds, beans, peas, processed soy products and seafood. Greek yogurt is currently not differentiated from traditional yogurt under the guidelines, and dairy products are designated under a separate classification from the other sources of protein.

In response to the letter, a U.S.D.A. spokesperson said “We appreciate Congress’ commitment to providing healthy, nutritious food to America’s children. We have received the letter and are in the process of reviewing.”

The state of New York is home to some of the industry’s largest Greek yogurt manufacturers, including The Dannon Company, Inc., Chobani, Inc., Fage USA Dairy Industry, Inc., and the soon-to-be operational PepsiCo, Inc., and Theo Muller Group joint venture manufacturing plant in Batavia, N.Y.

“Greek yogurt is packed with healthy protein and should be available to our children in schools,” Ms. Gillibrand said. “New York State is home to a strong and growing Greek yogurt industry. And when we connect these businesses to lunchrooms across the country, we can give our children better access to healthy, nutritious food, while strengthening New York’s own dairy industry. It’s time to make this commonsense change in our lunchrooms so our students can thrive in the classroom, and help grow our economy.”

In the letter to the U.S.D.A., Ms. Gillibrand and Mr. Hanna urged the Secretary of Agriculture to update the agency’s MyPlate nutrition guidelines to reflect the health benefits of Greek yogurt. They asserted that Greek yogurt should be permitted as an affordable, high protein option under the National School Lunch Program. They also argued that the inclusion of Greek yogurt in the National School Lunch Program would save school systems money while purchasing meals for students.

“With a burgeoning Greek yogurt industry in our backyard, New York schools are an ideal place to begin offering Greek yogurt as a protein in school lunch programs,” Mr. Hanna said. “By launching a pilot program in New York, schools could offer a high-protein, healthy lunch option for students at a considerably lower cost. The trial period would allow us to see the many benefits that could be gained by school districts, taxpayers, agriculture businesses and — most importantly — in the health of our children.”