The problem I have is I am trying to do a balancing act in being on a diet so I watch what I eat & drink and being able to keep myself hydrated and energised on a ride. The energy drinks give you the energy but works against you as they are quite high in calories (as you would expect). So if I do a long ride I should lose weight, but if I have to drink energy drinks (the same can be said of taking foods as well) to keep going you get to the point where one defeats the other and I don't loose any weight.
The electrolyte tablets I had to day are very low in calories but then you would expect that as they are more minerals as opposed to carbohydrates in energy drinks.
If I knew exactly how much energy\calories I burned during a ride and how much I had to drink\food I have to consume on a ride to keep me going then that would be great. I think I would burn more than I consume which would give you the weight loss during the ride.