How are the mini cliff bars as a mean for fuel? *attachment*

It has 23 vitamins and minerals, but it only has 100 calories per bar.
I assume I need high calorie fuel on a ride. I burn a little more than 1000 calories an hour at my body weight. I weigh myself before a ride. Usually when I get home after a 40-50mi. ride I weigh 3-4 lbs less.
Even though I consume 3lbs. of water + 3 mini cliff bars.

I understand the 3500cal per 1lb of fat. I really dont understand where I loose the weight, because I do not believe I sweat that much, however I really dont worry too much as long as I lose the weight.