Does it make sense that you would need the exact same amount of fuel every day?? (nope)
Aren't there days when you are hungrier than others due to hormones, activity levels or just because?? (yep)
Rather then setting yourself up to "cheat" on those hungry days and forcing yourself to eat more food than you want on your less hungry days, allow yourself the flexibility to adjust food intake base on your actual needs, rather then an arbitrary number!