Effect of protein intake/ protein quality on mood?

Due to a couple of expensive events occurring close together this month, my day-to-day food budget has been reduced, just for the month. So we’ve been eating a lot of soup and low-meat dinners.

Yesterday was one of the expensive events – an important birthday with a celebratory feast. For the occasion I bought a couple of large chateaubriand steaks and everybody had a generous portion.

Meanwhile, one of my roommates has been just hella grumpy during the same time period; far more grumpy than can be explained by simply being unhappy with the fare. (hey, it’s not like it’s been that bad anyway, I’m still a good cook.) He’s been so bad-tempered in fact, having disproportionate negative reactions to tiny things, that I was actually pretty worried about him having a tantrum and bumming out the birthday party.

Due to an emergency, the guest of honor was late; so to tide everyone over until he arrived, I served small appetizer steaks first.

The grumpy roommate was all smiles and a charming companion the whole evening! The difference was frankly startling. He swears that eating a good high-quality protein like the steaks has a lot to do with his sense of well-being and his whole outlook. This morning he said he woke up feeling like a million bucks.

My question: Is the effect probably psychological? Or could there be a genuine *physiological * aspect to it? Or is he just campaigning for more expensive grub in general? :cool:

It may be relevant to add that the guy in question is six foot seven. Maybe his protein requirements are significantly higher than other peoples’?

Taking a few hundred mg of amino acids like tyrosine, phenylalanine or tryptophan has been used as a treatment for depression because they convert into neurotransmitters involved in mood regulation. However (at least with tyrosine or phenylalanine) it is recommended to take them on an empty stomach and without other protein.