Chain restaurants in the United States are now required to post calorie counts for their menu items on site.

The rule was passed as part of the 2010 Affordable Care Act. It is one of the last rules to be implemented.

Chain restaurants with over 20 locations are required to take part, under the law. Restaurants must also provide on-site nutritional information like fat and sodium levels. 

Grocers, movie theaters and vending machines are also included in the law.