The meal allowances are just that, an allowance for your food. They are not a way to increase your salary like some airlines although some of our Delsi dinners and pot noodle brigade may think otherwise!
Allowances are based on the cost of meals in the hotel and are adjusted for discount. So, the net allowance from a hotel offering a 20% discount will probably be higher than one that offers 50%. Luanda will pay out approx $180 per day, Glasgow will net you around 55 quid. It's also dependent on the cost of living in the Country you stay in. As flight crew, some hotels offer lounge access, some include alcohol, some don't. Breakfast will be included in these. Internet access always available for flight crew and pursers.
To be honest, they do cover what they're designed for and i've never found it an issue......unless you drink gallons of booze and like ladies of the night!
Harry