It’s been just over five years since the Healthy Hunger-Free Kids Act (HHFKA) was signed into law, requiring foods served as part of the National School Lunch Program (NSLP) to contain more whole grains, vegetables and fruits. Now a new study published Monday in the journal JAMA Pediatrics reveals that school lunches have indeed gotten healthier, and close to the same number of students are still participating in the school lunch program.

The researchers looked at the nutrition quality of 1.7 million meals selected by 7,200 students in three middle and three high schools in an urban school district in Washington state. Data from students’ food selections were collected every day from January 2011 to January 2014, during the 16 months before and 15 months after the new nutrition standards were implemented for the 2012-2013 school year.

Get our Health Newsletter. Sign up to receive the latest health and science news, plus answers to wellness questions and expert tips. Please enter a valid email address. Sign Up Now Check the box if you do not wish to receive promotional offers via email from TIME. You can unsubscribe at any time. By signing up you are agreeing to our Terms of Use and Privacy Policy . This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply. Thank you! For your security, we've sent a confirmation email to the address you entered. Click the link to confirm your subscription and begin receiving our newsletters. If you don't get the confirmation within 10 minutes, please check your spam folder.

To assess the nutritional quality of the foods, the researchers calculated both the meals’ energy density (which is based on the number of calories) and the mean adequacy ratio (which measures six nutrients: calcium, vitamin C, vitamin A, iron, fiber and protein). The researchers also looked at how many students were choosing school meals.

The researchers found that the implementation of the Healthy Hunger-Free Kids Act was linked to students receiving more nutritious meals, with higher mean adequacy ratio and lower energy density. The changes are likely due to increases in the variety of healthy foods available, and more fruits and vegetables offered in larger serving sizes. In addition, the researchers found that the Act did not significantly change how many students chose the meals.”The combined effect of the standards along with other initiatives to improve nutrition environments in school settings may enhance attitudes about nutrition and consumption of healthy foods, both inside and outside schools,” the study authors concluded.

The authors added, “Because the National School Lunch Program reaches more than 31 million students each day in 99% of U.S. public schools and 83% of private schools, the new standards have the potential to significantly and consistently affect the nutritional health of children.”

One limitation of the study is that the researchers looked at the foods that were selected by the students and did not look at whether they ate the items. Prior studies have suggested young people sometimes throw away the healthier food instead of eating it. Also, some students have complained they weren’t getting enough food. In response, the government made some adjustments to the rules.

The new findings challenge arguments that fewer students are participating in school lunches. In October 2015, the School Nutrition Association and the School Superintendents Association wrote a letter to federal officials asking for more funding and flexibility, arguing the new standards are a financial burden and participation is down.

In an editorial about the new study, Erin R. Hager of the University of Maryland School of Medicine and Lindsey Turner of Boise State University write: “These groups claim that meal participation has dropped as a result of the HHFKA; however, these assertions are based on old data and an unfounded connection between dropping rates and the new standards…The [new study] adds to a growing and substantial amount of empirical evidence showing that school meal changes from the HHFKA have resulted in significant, valuable, and effective changes in not only the food environment but also in student behavior and health outcomes.”

In a statement sent to TIME, the School Nutrition Association said the group “supports the majority of the rules, including caps on calories, saturated and trans fats; mandates to offer a wider variety of fruits and vegetables; as well as requirements to provide whole grain rich choices in schools.” But the group says other evidence like a recent U.S. Government Accountability Office report suggests fewer students are using the school lunch program.

“We commend these six schools JAMA followed who have maintained student participation in meal programs, but the study ignores the unintended consequences causing nationwide decreased participation in the NSLP,” said Jean Ronnei, SNA president and chief operations officer at Saint Paul Public Schools in Minnesota, in the statement.

Contact us at letters@time.com.