Most chain restaurants, supermarkets, convenience stores and movies theaters must now post calorie counts on their menus.

Some fast-food chains like Wendy's have already begun posting calorie counts on their menu boards to help customers make more informed choices.

The new law went into effect Monday and will make big-chain eateries with more than 20 locations show customers how many calories are in each menu item. Smaller places like the Dairy King in Norwalk are in the clear.

The measure has been years in the making and is part of the Affordable Care Act from 2010. Most restaurants are in favor of the measure.

Studies show that providing information like calories helps both consumers and restaurants make healthier choices in buying and serving food.

"The reason it's important is that this country is going through an obesity epidemic," says U.S. Sen. Richard Blumenthal. "There's all kind of diet-related diseases like diabetes that are increasing in frequency and severity."

Blumenthal says restaurants that don't comply could face penalties and fines.