In 2008, New York became the first city in the United States to require fast food chains to post nutritional information on their menus.
Shortly after, a law enacted in 2009 forced chain restaurants in the Seattle area to put nutrition information on their menus. A study conducted 18 months after the menus were changed showed that entrees at sit-down chain restaurants averaged 73 fewer calories per entree and fast food chains saw a decrease of 19 calories after the labels were required.
"We can't say the menu labeling was the cause, because we could only look at restaurants in our jurisdiction," said lead researcher Barbara Bruemmer, of the University of Washington in Seattle.
She added that the study at least shows there is a benefit to providing the information.
Many restaurants across the nation will soon be forced to follow suit. The Affordable Care Act requires that restaurants with 20 or more locations across the nation to list information on calories, fats and other nutrients.
Studies in the past have linked eating out with obesity. According to the U.S. Department of Agriculture, a third of Americans' calories come from restaurants, nearly twice as much from what it was 30 years ago. The Centers for Disease Control and Prevention states on its website that obesity has dramatically increased in the last 20 years, and, currently, 35.7 percent of Americans are obese.