What was the population law in among the hidden?

In Among The Hidden the law was that you couldn't have a third child. it didn't really tell what would happen if they found a third child but Luke thought that the government would kill him. also the government made a law that you couldn't eat junk food like chips and soda, stuff like that and you couldn't have a pet. the reasoning they made all this law was that they wouldn't have much food and things like that if it was overpopulated