I've heard (from who even knows where) the rule of thumb you shouldn't make decisions when Hungry, Angry, Lonely, or Tired. I've added Sad to this, partly because it would help some friends, but also because it doesn't destroy the mnemonic. If you feel Hungry, Angry, Lonely, Tired or Sad, it HALTS your decision making until you're in a better place. Ideally.
I'm surprised this seems pretty uncommon, as a rule of thumb. Or maybe it's a regional thing, and every area has a different one, so I heard this particular mnemonic, but everybody has heard their own and they're all sort of uncommon. Or maybe there was a more implicit pro-social thing going on and it's a weird sign of the times that anyone would ever even think about needing an mnemonic for this.
But let me say: having a mnemonic helps for more than just remembering it. It helps me mention it to other people, to say, hey, I see you're in a place where you aren't going to be making the best decisions, ask for help or stick with your previous plans. It's hard to square away the wild impulses of Hungry, Angry, and Sad people and Lonely and Tired people need to hear something to get them going. Without the trite mnemonic, I'd have to think of something else, and it has to sound official, I guess.
It's also possible this whole arena of things is new because we're better at mental health than we used to be. It used to be, someone had feelings, that's obviously their own business and sort of disrespectful to take into full account – so far as I can tell, at least in America. I will say, there is a strong allure to the face-saving elements of this, but modern society is better handled by increased honesty.
And to be honest: you should just boringly follow your plans more often, I think. I've not met someone who followed their boring plans too much, I think. The most planningest person I ever met achieved most of their goals, became a successful doctor, and didn't let romance distract them from their ambitions. Without delving into their life too much, I will say I'm not entirely sure their current problems are a consequence of their megaplanning or a consequence of their personality (the one that produced the plan). I'm not sure which is the more generous assumption either. But they're an outlier – dedicating yourself to a 10+ year plan is way out at the end of the bell curve.
In the meantime, we're just making decisions in the moment, and when our momentary selves sort of suck, because we're hungry, we should ignore them. I hope you guys are sticking with your 2019 New Years diet Resolutions. :)