From a pure energy standpoint, even if there was a hundred percent energy conversion when a trolloc eats something - which is impossible - there still wouldn't be enough energy in the system to sustain a stable population, let alone grow a new one. At most, cannibalism is a supplementary form of food. It's impossible for it to be any more, unless energy and nutrients are being consumed in some fashion that doesn't involve food.

And if I recall, Jordan has some scientific - and physics? - background; he wouldn't ignore something that basic.