Eat protein rich foods. Carbs can make you tired especially if you start your day off eating.a carb filled breakfast. I don't suggest loading up on caffeine. Also, vitamin B-12 boosts your energy naturally.
You need a balanced diet, rich in fresh fruits & veggies, with good amounts of lean proteins, whole grains, low fat or fat free dairy, little to no fast foods or junk foods. Refined carbohydrates are your worst enemy: you get a quick rush, but then your blood sugar crashes, so you take more carbs, and you get locked into a rush/crash cycle. For excellent advice on how much of what to eat, go to www.choosemyplate.gov --scroll down to the bottom (after looking at all there is on offer) and click on "dietary guidelines". And by the way, choose my plate costs you nothing.