The comparison of power is done only when blockers are declared. Decreasing the power of a creature blocking Feasting Hobbit or increasing the power of Feasting Hobbit after this point won't cause Feasting Hobbit to become unblocked.

Devour Food is a variant of the devour ability. It allows you to sacrifice Foods rather than creatures, but otherwise functions identically to devour.

If you cast this spell, you choose how many and which Foods to devour as part of the resolution of the spell. (It can't be countered at that point.)

You may choose not to sacrifice any Foods for the devour Food ability.

Whatever you do, don't eat the delicious cards.

Food is an artifact type. Even though it appears on some creatures, it's never a creature type.

You can't sacrifice a Food to pay multiple costs. For example, you can't sacrifice a Food token to activate its own ability and also to activate Maraleaf Rider's ability.

If an effect refers to a Food, it means any Food artifact, not just a Food artifact token. For example, you can sacrifice Tough Cookie (an Artifact Creature — Food Golem) to activate Maraleaf Rider's ability (an ability with "Sacrifice a Food" in its cost).