Exercise and drink lots of water.

Hmm.  I don't really eat any FOODS per se to perk me up.  What I do though, is make sure I space out my meals into 5-6 meals a day (I'm sure you've heard of this already) in small amounts so that the food doesn't weigh me down and make me feel sluggish.

If you're looking for something to take as a supplement though, Twinlab's Ripped Fuel works well -- although it has caffeine in it.  I take two of these every day in twice-daily supplement stacks as a metabolic enhancer.  Warning though -- if you're not used to taking this kind of stuff, this one is pretty strong, it can make people nauseous and super hyper.

I think Age has SOME part to play, but I can say it's not as significant as people think.  It's all in the mind.  I've been a competitive fighter for 21 years now (yes, I'm old), and the only times in my life I felt like I was sluggish and tired were times when I was generally in poor health (relatively speaking).  Perhaps this is something to look into -- a lot of times when people are tired all the time for no real reason, there's some kind of underlying medical condition.

If you have access to a good TCM (Traditional Chinese Medicine) Doctor, he may be able to identify and treat problems with your internal energy, or Qi, that could be causing your problems.  Freeing up your circulation, not only with Qi, but with your blood as well, increases vitality a LOT.

Back to food though, I don't know what your diet is like right now; but a lot of people who go from eating more processed foods to more "raw" foods, or eat less meat and more vegetables, fruits and grains, tend to get a lot of energy back.

I am not sure why, but a lot of fruits kinda does it for me, especially oranges and pomegranate.  It could me the burst of vitamin C or that combination of juicy sweet & sour taste that gets me going.  It's kinda weird actually.  Yeah, caffeinated beverages always "de-energizes me."  Also, make sure to drink plenty of water or keep yourself hydrated because dehydration just makes you feel tired.  Get enough sleep, not too much and not too less, the average 7-8hours, it's usually better for your body to have a routine because then it will function properly.  Morning stroll with a partner or pet also makes you feel refreshed and ready to tackle the day.  Oh, and never skip a meal because this will just throw off your entire body and all you think about is food.  In addition, exercise frequently to use the energy, so that your body will refill that energy.  You'll be amazed that you may feel dead tired, but one you get up and move, your body just feels more energized with you blood circulating.  If you are ever extremely sleepy and are short on time, find a place and take a quick 5 minutes nap.  I don't know the reason, but this helped me on several occasions.  The 5 minutes nap was like a "reboot" for my body and it certainly got me more pumped up and ready for more work.  Hope some of these tips will help you!  

These are all very helpful, thanks!

banana has alot of natural sugar as much as a chocolate bar. i think it's good to eat in the morning or afternoon, and it keeps me in a better mood from a long school day. i eat one almost everyday..

- Ice Cold Water
- Whole Eggs
- Pureed Pumpkin
- Ostrich & Elk Burgers
- Salmon
- Spaghetti Squash
- Bell Peppers
- Turkey Slices
- Cherry Tomatoes
- Nori Sheets
- Acorn Squash
- Butternut Squash