In my Performance Enhancers post, I remarked about an energy formula called RedLine. My observation after using it for a few months is that the drink seems to be effective for weight loss in addition to building energy. RedLine was a bit hard on my heart, so I sipped about a fifth of a bottle a day rather than the recommended half of the bottle, and switched my primary drink backed to Rockstar.
A few weeks ago, I tried a new energy drink, FRS healthy energy. I was actually impressed by its effectiveness with few calories and no caffeine. Unlike the other two products, my energy feels eerily natural. I was actually skeptical after the first day of use, because I expected to feel some kind of artificial kick but instead experienced a sustained (possibly heightened) "normalcy" in my energy level, the kind of energy one feels early in the day. Only after several drinks in one sitting, after which I was unable to sleep for a whole night yet was energetic as ever, did I come to the conclusion that the product was real.
This may be something that I could use on regular basis without worrying about the future risk of heart disease.