10 calories for 1 calorie of food

[PhilKravitz]

When people say it takes 10 calories of energy to produce 1 calorie of food are they taking into account the fact that food calories are actually kilo calories? Does it really take 10 kilo calories of energy to make one kilo calorie of food energy? Or do they mean 10 calories of energy to make 1 kilo calorie (1000 calories of food) of food energy?

 

[Pengwuino]

I'm sure they have their units correct and it takes 10x as much energy to produce food. Some foods are probably ridiculous in this comparison. A piece of lettuce? How much food energy could that possibly store? Then think about all the energy it takes to harvest foods like that, process it, transport it to a store, etc.

 

[PhilKravitz]

on the other extreme we have beans

 

[TheTechNoir]

To my understanding it would be against the nature of entropy increase over time for 0.01 kcals being sufficient to produce 1kcal of food. Which, while not impossible is tremendously unlikely. Especially to such a huge magnitude.

 

[Phrak]

Does it take 10 calories from fuel to produce 1 calorie in the form of ethanol derived from corn?

 

[PhilKravitz]

To my understanding it would be against the nature of entropy increase over time for 0.01 kcals being sufficient to produce 1kcal of food. Which, while not impossible is tremendously unlikely. Especially to such a huge magnitude.

There is energy input from sunlight on the growing plant. We are talking about energy in fertilizer and tractor use and truck distribution.

Yes if I grow beans in my back yard with no added fertilizer and pick them by hand and walk them to the kitchen yes we can have 1 kcal of food with 0.01 kcal of energy from sources other than the sun.

 

[PhilKravitz]

Does it take 10 calories from fuel to produce 1 calorie in the form of ethanol derived from corn?

You make a good point if it really did take 10 cal to make 1 cal ethanol would be a bigger looser than it already is.