It's all true.
A friend of mine stayed with Greg for 1 week and witnessed him typically eat upwards of 20 000 calories per day.
He ate an obscene amount of junk food. They went to McDonalds and Greg chowed down on 40 mcNuggets, 5 Big Macs,
3 Litres of Coke and 12 apple pies, plus a tonne of Onion rings and side orders of x-large fries.
This type of binge only satisfied Kovacs for 2-3 hours, and then it would be time to eat a similar amount again.