People visiting their favorite fast food chain this week might notice something different. Menus in the stores and drive-thrus will now be required to list the calorie counts for each item offered for sale, from doughnuts to burgers to double lattes, as Thrillist highlights.

Then again, you might not notice anything at all. Since the Food and Drug Administration first proposed the regulation under the Affordable Health Care Act in 2010, a number of restaurants have made the switch to full calorie disclosure because they expected the law would eventually come into effect. Beginning May 7, it’s official. Any chain eatery with more than 20 locations will have to list the information.

The move is intended to make consumers more aware of how many calories they’re consuming when dining out. While food chains haven’t objected to that, some have taken issue with the logistics. Pizza chains that largely do business by way of delivery argued that the law was too impractical, and revisions to the bill have made exemptions in such cases. (You’ll find those formidable pizza calorie listings online.) Amusement parks and movie theaters will also have to comply.

Does it work? One meta-analysis published in the Journal of Retailing documented an average reduction of 27 calories per meal, or 83 calories per meal if the consumer was already dealing with a weight issue. FDA Commissioner Scott Gottlieb told CNN that other data shows an average 50-calorie decrease in consumption per day.

[h/t Thrillist]