An artifact, likely named “The Fast [something]”, which grants speed, but also prevents you from eating because fast also means to refrain from eating.

There are adverse effects if you swim within a certain amount of time after your last meal, because of the traditional advice that it’s dangerous to swim less than an hour after eating.

Add two new elemental planes, those of Positive Energy and Negative Energy.

The Plane of Positive Energy:

• The full level is lit.
• Has lots of yellow lights, trees, and whatever plant-based monsters exist in the game.
• Everything is treated as if it has regeneration. The player can regenerate current HP past its maximum, but if this gets too far past the maximum, they instantly die from being unable to contain the energy (there are warning messages to this effect as you approach this point).
• Items in the player’s and monsters’ inventories can randomly get blessed, enchanted, or charged - even if this runs the risk of overenchanting and destroying them.
• Eating any food restores HP as well as nutrition.
• All exercisable attributes are exercised at regular intervals.
• All sleep effects are negated.

The Plane of Negative Energy:

• The full level is dark.
• Contains lots of undead.
• Everything constantly loses hit points. If you have regeneration, it either nullifies or only partly nullifies this effect.
• Items in the player’s and monsters’ inventories can randomly get cursed or lose enchantment or charges (going negative on things which are capable of being negative).
• You lose several times as much nutrition per turn as normal.
• All abusable attributes are abused at regular intervals.

Everlasting gobstopper, a food item that you start sucking on when you eat it, providing a constant d2 nutrition per turn. It never gets used up, but once you spit it out (by choosing to eat something else or by using “-“ with the eat command) it is no good anymore and gets used up. If you get oversatiated by not spitting it out, you can indeed choke and die on it.

If a dwarf sees you eating a dwarf corpse, he grows enraged and gains to-hit and damage bonuses. This may also extend to other races seeing you eat their fellow kin, though orcs might just laugh instead.

Eating any kind of fish may increase your Intelligence, because of the popular wisdom that fish is “brain food”.

You can get some rare intrinsics by eating artifacts that confer them. For instance, eating Excalibur could give level-drain resistance, or eating Grayswandir could give hallucination resistance.

The chance would be much less than 100%, possibly even lower than the standard odds of getting an intrinsic from eating jewelry.

Cursed wind instruments (bugle, whistle, most horns) stick to your face when used, preventing you from using #chat or making other forms of conversation (to shopkeepers, demon lords, priests, etc, though most of these are ambiguous on whether the hero needs to speak) and possibly also preventing eating.

Alternatively, using the cursed wind instrument could simply produce “You hurt your vocal cords!” and make you mute for some length of time.

If you eat a corpse of a monster that drank a potion just before dying, you have a chance of getting some effect from the potion too.

Eating too much food can give you a ‘hiccuping’ intrinsic, where you sporadically hiccup and wake up monsters. Drinking more than two potions of booze in quick succession can also do this. You can cure the intrinsic by drinking a fizzy potion.

If you are polymorphed into an inediate monster, you are physically incapable of eating.

Eating corpses gives you a temporary “queasy” intrinsic, which is a debuff on par with being burdened. This is aimed at fixing the irrelevance of the game’s hunger clock.

Remove the possibility of “Blecch! Rotten food!” from uncursed non-corpse comestibles.

If you die from overeating and then are lifesaved, you automatically finish eating.