Despite students' complaints over growling stomachs, the new nutritional requirements should actually be making them feel fuller, said Kristi King, a registered pediatric dietician at Texas Children's Hospital and a spokeswoman for the Academy of Nutrition and Dietetics.
The new rules double the amount of fruit and vegetables that are served and mandate that half of all bread products are whole grain. All three of those food types are chock full of fiber, which takes longer to digest, King said.
"It should be making kids fuller if they are actually consuming the whole product," King said. "If children are not picking the entire meal available to them they are obviously going to be hungry."
In Jackson, Miss., the state with the highest obesity rate, school cafeterias have been easing kids into the healthy food regulations.
Mary Hill, the executive director of food services at Jackson Public School District said her school district has been phasing in more fruit and vegetable options over the past few years to prepare for the regulations and while the new rules are an "adjustment" for the students, she said she has not heard any complaints.
"To me, if you hear that grumbling it's that typical grumbling with children," Hill said. "You know children will be children." ABC News' Arlette Saenz contributed to this report.