Diet's effect on mood is real, though often overstated in either direction - a handful of consistent, evidence-backed patterns matter more than any single "mood food" myth.
Skipping meals and then eating something high in refined sugar creates blood sugar swings that correlate with mood swings - eating regularly, with a mix of protein and fiber, keeps this more stable.
Mild dehydration measurably affects mood and concentration well before someone would describe themselves as "thirsty" - a consistent hydration habit throughout the day is an easy, underrated mood-support factor.
Mood benefits from nutrition come mostly from overall consistent eating patterns, not any single food added to an otherwise unchanged diet - a more useful focus than searching for one ingredient that will fix everything.