Celery, a comestible which uniquely has negative nutrition (because in real life, it takes a human body more calories to digest the celery than are in the celery.) The main use of this negative nutrition is to unsatiate yourself so you can continue eating other food.

It should be a large amount of negative nutrition in order to be worthwhile, but at the same time shouldn’t be instadeath for unsuspecting new players by immediately starving them. To that end, special case it so that it does not harm you if you are Hungry or worse, is worth -30 nutrition if “not hungry”, and is worth more negative nutrition if Satiated, possibly scaling up the more satiated you are.

Depending on implemenetation, it could either be safe or unsafe to eat when oversatiated - realism dictates it should be unsafe to eat, but gameplay dictates it would be useful in fewer situations unless it is always safe to eat. Or have it count as a small positive nutritional value assessed before maybe choking, followed by a large negative nutritional value assessed after you didn’t choke.

Knights still incur alignment penalties for eating celery while satiated.

The celery also crunches loudly whenever eating it, so it wakes up nearby sleeping monsters.