The new rule requires restaurant chains, grocers, convenience stores, movie theaters, and even vending machines with over 20 locations to post calorie counts for their foods. The long road from the passage of Obamacare in 2010 to the implementation today included three delays after the rule was finalized in 2013.

The Trump administration has not supported many Obamacare initiatives, but allowed this one to come into effect. Conservatives in Congress are still not happy with the legislation, and have tried to make amendments to the rule, but the national standard has the support of the National Restaurant Association, which wanted to help its members avoid complying with patchwork laws at the state and city levels. The Trump administration quietly fought the implementation of at least one of these municipal standards last year.

Studies have found that calorie labelling can reduce the amount a person consumes by 12%. Though these calorie savings are small when taken on their own, Food and Drug Administration Commissioner Scott Gottlieb says they add up to a “meaningful, incremental step” towards fixing the country’s obesity epidemic.

The FDA is expected to focus on educating restaurants on how to comply rather than enforcing the rule during its first year in effect.