This probably won't come as a surprise to most if you but fruit has magic energising powers. I note this because when I started the new job, I went dutifully to the supermarket and bought lots of fruit and vegetables to eat in my packed lunch. After chowing down on a protein rich sandwich and several portions of fruit every lunchtime I was energised.
Poor organisation/laziness has lead to me sticking a prepacked sausage roll and a chocolate bar in my bag recently and I've not been feeling so perky. Admittedly I have a cold, but I'm seeing a correlation here. I might even take a ride out in my soon to be sold car to buy some more.