EFFICIENCY
  • You eat food to live.
  • Most of the energy in the food you eat is wasted (you are not a very efficient machine).
  • If your body were more efficient, you could be just as active as you are now yet eat less food.
  • This idea of input (food) compared to output (activity) is called efficiency.
  • We can study efficiency for any machine, from humans to drag racers.
    Mathematically speaking,


    • EFFICIENCY = OUTPUT/INPUT

    Solving the equation "as is" gives us a decimal answer.  Since many folks are accustomed to hearing efficiency as a percentage, we can just multiply our answer by 100...

    E=(OUT*100)/IN
    and
    IN=(OUT*100)/E
    and
    OUT=(IN*E)/100



    If you eat a 300 calorie snack, your body may use only 30 calories of this energy for actual work while wasting the rest as heat.  How efficient are you?

    We want "E", so use E=(OUT*100)/IN and plug in the #'s; (notice that the "cal" cancels out)
    (30cal*100)/300cal = 10%