It is certainly common practice to not include lunch as work time in the US. But I think that is unfair to the employee.
In the US almost all Low-skill jobs that pay by the hour dont count lunch as work time. At those jobs you usually explicitly "clock out" for lunch.
At salaried jobs it is less common, though I'd guess 50% or more don't count lunch as work time.
If that is the case, then workers should also be allowed to eat at their desk (or otherwise eat while working - reading emails on phone, etc) and leave early if they spend less than an hour at lunch.
Perhaps this is regional, but I don't know anyone in a salaried position that gets paid for lunch time. It is always expected that you are working 8 hours a day outside of the lunch hour.
I started work at 9. I'm responding to your comment while eating lunch at a restaurant. I plan to leave around 5 today. This is my normal schedule. I'm salaried and live in the US as well. My last two jobs were the same way as well.
I have a cousin with a union job. Her union negotiated 8 hour day with mandatory paid half hour lunch. The lunch is negotiated as mandatory so they go around and make everyone leave their cubicles at lunch time. Perhaps to make sure no bosses are expecting people to work through lunch.
In the US almost all Low-skill jobs that pay by the hour dont count lunch as work time. At those jobs you usually explicitly "clock out" for lunch.
At salaried jobs it is less common, though I'd guess 50% or more don't count lunch as work time.
If that is the case, then workers should also be allowed to eat at their desk (or otherwise eat while working - reading emails on phone, etc) and leave early if they spend less than an hour at lunch.