Having worked under two different systems, Oz, no such thing as a 'dinner/meal break'. you are only guaranteed a total of 20 minutes break per shift (or it least it was like that). Reality was effectively much better than that. The rostered hours were averaged through a 'roster cycle' for a 36 hour week and that's what you got paid against.
In Ireland the meal break was guaranteed, you were rostered for a 'gross' hours but worked a net hours, because meal time was your own, you were paid against the net hours.
In Ireland you were also free to leave the compound during your meal break; in Australia you had to beg and plead for permission to leave the compound during a shift.
Of course the trade off was that longer 'rostered on time'...
The later was a much better way to work.