Dextrose tabs are definitely short term energy boost. Still, something you may want in your "bag of tricks." For longer term, I turn to peanut butter.

The key difference with candy, is that they are pure glucose (dextrose is simply glucose by another name). Candies usually turn to sucrose, which is about half glucose and half fructose, as Sucrose is much sweeter than glucose. It requires some digestion, and this is where the questions arise about the fructose, and it's possible involvement with a variety of heath problems. The same health questions apply to the high fructose corn syrup in many products. In terms of effect on the body, they have similar if not identical effects.

Rather than drink a can of soda pop or an energy drink, I think a couple of dextrose tabs and some plain water is as effective as an energy pickup without the potential long term effects of sucrose and/or high fructose corn syrup.