uFuel is a more intuitive calories that gives your body a fuel gauge. Record your calorie input/output, and watch your gauge move as you go throughout your day. Go ahead and eat whatever you want and keep track of what you have to burn in the future. Even if you go over your allowed calories for the day, you can see how long it actually takes to burn it all off!
You wouldn't buy gas for your car if you had a full tank, why would you put energy in your body if you don't need it?