Eating enough healthy food to satisfy the government's nutritional guidelines can be prohibitively expensive, with potassium alone adding $380 to the average person's grocery bill, a study found.

Researchers from the University of Washington examined the effectiveness of new U.S. dietary guidelines, which attempt to combat a ballooning obesity epidemic by recommending nutrients like dietary fiber and vitamin D while warning against saturated fat and added sugar. They compared the eating habits of 1,123 Washington state residents to prices at local grocery stores and found that altering your diet to match the recommendations can add significantly to food costs.

"We know that dietary guidelines aren't making a bit of difference in what we eat and our health overall," said Pablo Monsivais, acting assistant professor at the University of Washington and one of the study's authors . "And I think one missing piece is that they have to be economically relevant. They emphasize certain foods without much regard for which ones are more affordable."

The study determined that wealthier Americans were more likely to eat healthier food, a finding that suggests how deeply intertwined obesity is with socioeconomic status. Monsivais said that the government should be doing more to publicize the nutritional value of inexpensive items like bananas and potatoes, both of which are high in potassium, in order to dispel the impression that eating right is a luxury.

"Given the times we're in, I think we really need to make our health guidance, in particular the dietary guidelines, more relevant to Americans," he said.

Hilary Seligman, assistant professor of medicine at the University of California, San Francisco who studies healthy eating and food insecurity, echoed Monsivais' concern. She noted that many households choose what food to but based on cost, rather than on the nutritional facts listed on the label.

"Almost 15 percent of households in America say they don't have enough money to eat the way they want to eat," Seligman said. "Right now, a huge chunk of America just isn't able to adhere to these guidelines."