i don't know if this is the right place for such a question, but Im having an exam over five hours tomorrow and Im wondering what are the best things to eat before and during it to keep my brain working to its maximum ??
Is it in the morning? Good strong breakfast with little fat and lots of carbohydrate, e.g. Lots of cereal/toast. Take a sugary drink into the exam and take it part-way through.
Lunch? Big lunch, but not too big or fatty (It'll make you drowsy). Instead, a good balanced meal and again, a sugary drink to keep your energy levels up. Coca-Cola is sugary enough (~10g sugar/100ml), there's nothing to be gained by taking a drink that is more sugary (e.g. energy drink).
Energy drinks have the same amount or more sugar, plus a lot of caffeine or Turine (a precursor of caffeine). I'd say that in the exam you're mor than likely to have enough adrenaline sloshing around in your body so that you don't need it.