February 17, 2013
This display at a local Meijer presents 66 containers of Lofthouse frosted cookies sealed with a label having a Valentine's Day theme. The total cost is $132. This is a discounted price because Valentine's Day was three days ago. Each container holds 10 cookies. A single cookie provides 160 Calories according to the nutritional information attached to each package. A little math indicates that this display offers for sale a total of 105,600 Calories at a cost of one-eighth of a penny for each Calorie or one penny for eight Calories.
The total caloric content of the cookies is enough to provide 52.8 adults with 2,000 Calories each. The cost for those 2,000 Calories is a mere $2.50. If you are willing to eat 12.5 Lofthouse frosted cookies to supply your daily caloric needs, you can live fairly inexpensively until the overall lack of nutrition catches up with you.
Converting nutritional Calories to Joules, we find that the total energy in these cookies is 442 megajoules (MJ). According to the Wikipedia entry for gasoline, a gallon of gasoline provides approximately 35 MJ of energy per liter (L). This display of cookies is therefore the equivalent of 12.6 L of gasoline. In Imperial units, that's about 3.3 gallons. AAA's website reports on February 17, 2013 that the national average cost for a gallon of regular gasoline is $3.714. If the energy of the cookies were provided as gasoline, the total cost would be $12.26, which is considerably less than the $132 for the cookies. In my car, which can travel about 38 miles per gallon, those 3.3 gallons would take me about 125 miles.
This analysis taught me two things.
- Traveling 125 miles in my car is the energetic equivalent of feeding about 53 adults for a single day.
- The cost of nutritional energy is greater than the cost of gasoline even when the nutritional energy is provided in a highly undesirable form.
This is why it takes me a long time to finish shopping. Every display makes me think of things like this.