Schools in my state would not be able to do that - students must have a lunch period. You can't opt out of it.
Also, lunch is never the same length as a class period - it's built into a class. A lunch would go to lunch, then the entire class. B lunch goes to 25 minutes of class, 30 minutes of lunch, 25 minutes back to the same class. C lunch does the class then lunch. Students would then start the next class period at the same time. Even the high schools with block scheduling have the lunch built into a class period.
The only person who I know who can skip lunch to double up on classes is Hermione Granger.