Like LWilson said, eating and sleeping habits play a HUGE part in energy levels. Every person is different. Try to pay attention to what your body needs and try different scenarios. Make sure you give each scenario plenty of time, though. Our bodies are pretty slow at adapting to new things. I wouldn't go less than four weeks on a plan before I tried something else. Also, take some "good" multivitamins. When I say "good" I mean, not a Walmart vitamin. Go to a health food store and check labels. Most good vitamins will provide Thousands in the percentile of the RDA ratings. Doctor's Choice and Life's Fortune are some to look for.
Almost forgot. Drink LOTS of water!!! Making myself drink a gallon of water a day(Yes that's right a whole gallon ) has made more of a difference than anything. Everything is more consistent and believe me, it will keep your system flushed. :D