As a matter of fact, it is- monster food converts directly to energy when eaten, due to being infused with magical energy either while the food is grown or during the cooking process.

Some monsters can eat as humans do, if they so choose, but others don't have the option, generally due to lacking anything much in the way of a physical digestive system.

[She looks at him thoughtfully.]

It sounds quite like you've encountered monsters before, but the way you say 'in your world' makes me suspect that you're not from home.