Athletes are a good example of people who really do need to track their diet and exercise efforts in order to maximize their performance.  Sure we've heard some athletes boast that they consume candy and caffeinated soda to "fuel their performance" - we'll never know if they were to shift their consumption to healthier choices if their amazing performance would become....even more amazing.  What we do know is that Celtic's guard Ray Allen did realize that eating a cheeseburger or two before...