Is it really illegal?

For bosses and managers to not allow at least an hour of lunch break but only 5-10 minutes?
Only if you work 8 or more hours in a given shift.
It's illegal to not allow 2-3 fifteen minute breaks.. Lunch is mandatory - 30 minutes to an hour, depending on your title.
I agree with Only-P about eight hours. If your work day consists of eight hours they must give you time off for lunch plus two breaks. Even though, the lunch does not have to be on their time. This means that you might work from 8am to 4:30 pm and only get paid for 8 hours, because the 30 minutes for lunch is your time.

Someone told me that a company must employ over a certain amount of people for the law to apply. I'm not sure if he was right.
What are your hours? No it is not illegal to limit a lunch hour.
In Texas there is no law governing breaks AT ALL. Google hour and wage commission for your state.
If you work an 8 hour day, then you must have a half hour for lunch and two 15 min breaks. If you work less then five hours you get one 15 min break.


Answer:
Depends on the work day. If the work day is 8 hours they have to allow for a 1/2 hour lunch but if its not even 5 hours they don't. The shift or work day must be defined to answer your question.