Remember when we say food Calories, we actually mean kilocals. HOWEVER, while fuel itself may be more efficient to move, you always end up moving a very heavy i

Remember when we say food Calories, we actually mean kilocals. HOWEVER, while fuel itself may be more efficient to move, you always end up moving a very heavy item (the car) thus you always do better by not moving the car. AND that person inside it as well. However, we also must account in addition to fuel cost, the cost of the person breathing. A person's standard breathing vs ~ double for exercising. So a person sitting inside that SUV is already creating ~ half the CO2 that a biker would. Then the final note: Gasoline is a very finite supply. PB&J for all practical purposes is 100% renewable.