My view would be an hour. The other day I was in the CX F Lounge in T3. I managed to get on of the throne seats by the window.

I relinquished it to go and have lunch - it took less than an hour. It depends if you are refuelling or savouring the meal. I has noticed that most business people tend to eat if not fast but without really pausing or stopping. I think that the throughput is such most people are on their own and are not talking to anybody, or even they are couples if they are married then they stopped speaking years ago! I was casting my mind back to the QF lounge in LA and I would say off the top of my head that it would be an hour to 75 minutes most. in the Flounge one has no such concerns as it has gone back to these dip buffets we just pile your plate off and go and pig out elsewhere. The CCR is far more gracious and I would allow there 1.00 - 1 1/4 hours.