“Some places now have a law that requires fast food restaurants to label each item with how many calories it has.”
You're having a conversation with a friend from another country. You're talking about fast food and how unhealthy it is. You mention something that you've seen in fast food restaurants in some cities that you've traveled to.
Some places now have a law that requires fast food restaurants to label each item with how many calories it has.
An "item" is basically just a thing. The word "item" usually means one thing in a list or a group.
The things that are sold in a shop, an online store, etc. can be called "items":
I got it from a store that sells all kinds of art and handmade items.
A new law requires that fast food restaurants label each item with the number of calories it contains.
Some laws "require" people to do things. In other words, people have to do some things because of laws. For example:
The law requires gun owners to register their weapons.
You are required to submit your appeal within 30 days.
You can use the form "___ requires ___ to ___" as in the examples above, or you can use the form "___ requires that ____" as in this example:
There's a ridiculous new law that requires that any livestock, even backyard chickens, be registered with the state government.
A "label" is some written information that you attach to something. A lot of the food that you buy in a store is "labeled". You can decribe what's on a label using the phrase "label ___ with ___":
Everything is labeled with the date and an ID number.
Can you label all of the stuff that you brought with your name?
"Fast food" restaurants are places where you can get cheap food quickly. In the U.S., hamburgers are the most common fast food. There are also fast food restaurants for tacos, fried chicken, and sandwiches.
You can talk about the food itself as "fast food":
I try not to eat too much fast food.
Or you can talk about the restauraunts that sell fast food:
There sure are a lot of fast food places around here!
If I'm on a road trip, I usually just stop and eat at a fast food restaurant.
"Calories" are a measurement of the amount of energy that's in food. Some food items are labeled with the number of calories. People who are trying to lose or gain weight might discuss how many calories different kinds of food have.
Do you have any idea how many calories those french fries have?