Further clarify about hourly-paid and on salary

If you are hourly paid, and you take time for lunch, you don't get paid for your lunch time.
If you are on salary, and the company's policy is one-hour lunch time, you have to take that hour out of your total working time. Therefore, you have to be in office for at least 9 hours each day.
But different company has different policies. You can talk to the HR department and get a copy of your company's policy.