I was there last month and was given LOA for a trip that lasted 12 days. Off the top of my head it was somewhere in the region of £15 - £20 per day. The tuck rates we were given were up to $10 for breakfast and up to $52 for the rest. These were USA Off Base rates. Also got LSA for the period. As has been said though that is a lot of cash to try and eat in even some of the better establishments in the US. We were lucky if we got through $30 - $40 a day.