(CNN)– A new study reveals higher prices at the grocery store are keeping most American families from eating healthy.

According to a new survey published by the Pew Research Center, eating healthy is a bigger challenge for lower-income adults.

More than two-thirds said increasing food prices make it difficult to eat a healthy diet.

But middle and upper class households have also reported struggling due to costs.

Overall, objective measures of diet quality in the U.S. showed the American diet is substandard.