I was recently challenged to figure out the "mileage" a friend of mine gets on his bicycle as a function of gallons of milk ingested. More succinctly, how many miles does he get per gallon of milk when riding his bike. Of course this depends on the type of fuel (Whole milk, 2%, or skim), the speed at which you are riding, body weight, percent body fat, basal metabolic rate, etc. For the purpose of these calculations we will assume a normal adult male of about 160 lbs. Of course we are also assuming that you ingest nothing but milk...
To wit - you can expect the following mileage:
Pretty efficient really - or is it? Just how much energy does it take to get a gallon of milk from the cow to you? How much energy does it take to grow the cow?
For now, let's assume that the cost of milk is roughly equal to the cost of regular gasoline and look at a direct cost analysis/mileage. Both my Prius and my scooter beat the milk as fuel alternative for my bike. (I drink only skim milk). Whole milk is the best fuel - and riding slow gives me a bigger bang for my buck - but the three hour commute each way would make getting my job done a difficult trick. For now I will stick with my motorized vehicles for commuting and my bike for shorter trips, and for fun.