When my dad was a 12-year-old kid in Red Bluff, California, circa 1928, part of the extended family was a man he knew as Uncle Jack Cotney. That they knew of, or he'd admit to, Uncle Jack had survived some 25 stand-up gunfights in his life.
Green tea is a fat burner that does speed up the metabolism, as far as energy drinks however they really speed up the heart not your metabolism. If you're looking for something that will speed up your metabolism there are better choices for that. Good Luck, Casey.
Studies do show that caffeine intake can increase your metabolism, but the effects only last for a few hours are much less pronounced in obese people. In other words, people who need to lose significant amounts of weight are much less likely to have their metabolism boosted by caffeine.