The study said that the average U.S. citizen eats about 200 sandwiches a year, and the average child will eat around 1,500 peanut butter-and-jelly sandwiches before graduating from high school, Texas A&M found.

The difference between a healthy and unhealthy sandwich was also brought to question.

"There's nothing wrong with most sandwiches but it all depends on what you put on them and serve with them," said Steven Riechman, assistant professor of health and kinesiology at Texas A&M University.

"You have to start off the right way -- with the bread and meat. The bread should preferably be whole grain, not white. The whites have the highest calories and lowest fiber content," he said. "And the leaner the meat, the better."