Popcorn is on the list of whole-grain foods included in the U.S. Department of Agriculture’s Dietary Guidelines for Americans. It is fourth on the list of most commonly consumed grains in the United States, after whole wheat, whole oats and whole-grain corn. That makes it a significant contributor to the grain and fiber intake of the average American. At least half of the six daily servings of grains recommended in the dietary guidelines should come from whole grains. According to a study published in the May 2008 issue of the “Journal of the American Dietetic Association,” popcorn eaters consume more than twice as many whole grains and more than 22 percent more fiber than people who don’t eat popcorn.