My BJJ team mates and I, have for several years now, been using honey as a simple carbohydrate supplement prior to and during our matches at tournaments. We never really thought twice about the matter, as it seemed straight forward to us: honey is a simple carbo-hydrate that is natural and comes in an easy to use format. We were able to maintain (or so it seemed) a decent amount of energy throughout the duration of the tournament by taking a few table spoons prior to the first match, with smaller servings in between matches if we need it. Recently, we introduced the magic of the "Honey Bear" to our judo club and had some success with using it during judo competitions (picture above with trophy and the Honey Bear).
Check out the nutrition data on honey here. Learn more about the Glycemic Index here.