Yeah I’m sure that is a problem too.
Not to mention all the other malnutrition effects.

Scurvy. Low vitamin D Low vitamin B1 leads to specific memory neurons dying. Permanently. That’s why long term alcoholism causes permanent memory impairment. Anemia from low iron It’s also super important that you have salt in your diet. And vitamin k.

I’m not sure how long you can go without those but probably not that long.