I used to think that male aggression and the need to compete was just the way men's hormones made them.
However, most of the aggression and fighting I see on the streets (and in driving) now seems to be from young women.
In my experience, hormones seem to play a far larger part in the desire to fight than food. I do know that chocolate can help with PMS, but not of any male equivalent.
On another foodie topic - cow's milk has now been identified as having great qaulities in muscle recovery after a workout etc. All this research, 'proving' that it is a 'super-food' and much better than protein shakes - and all they had to do was work out that 'whey protein' is a bit of a give-away to the origins of the stuff people have used for years.
Nemo - if the vegetarian food you eat leaves you feeling like you have low blood-sugar, it may just be a matter of increasing slow-release carbs, such as oats. In fact, you have to be really careful with many processed veggie foods as they can have huge amounts of sugar and fats such as palm oil. I find it helps if I knit my own muesli.