10 calories for 1 calorie of food

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Discussion Overview

The discussion revolves around the energy cost of food production, specifically the claim that it takes 10 calories of energy to produce 1 calorie of food. Participants explore the implications of this ratio, considering units of measurement, the types of food involved, and the role of energy inputs in the production process.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Exploratory

Main Points Raised

  • Some participants question whether the 10 calories refers to calories or kilocalories, seeking clarification on the units used in the claim.
  • One participant suggests that certain foods, like lettuce, may have a particularly low energy yield compared to the energy required for their production, highlighting the complexities of food energy economics.
  • Another participant introduces the concept of entropy, arguing that it would be highly unlikely for a very small amount of energy (0.01 kcal) to produce a larger amount of food energy (1 kcal), although they acknowledge this is not impossible.
  • There is a specific inquiry about the energy input required to produce ethanol from corn, with participants questioning the validity of the 10:1 energy ratio in this context.
  • One participant mentions that energy from sunlight is a significant factor in food production, suggesting that the energy cost can vary greatly depending on the methods used, such as growing food with minimal inputs.

Areas of Agreement / Disagreement

Participants express differing views on the validity of the 10:1 energy ratio, with some supporting the idea while others challenge its feasibility based on various factors, including food type and production methods. The discussion remains unresolved with multiple competing perspectives.

Contextual Notes

Participants note the importance of defining units correctly and the potential variability in energy costs based on different agricultural practices and food types. There are unresolved questions regarding the specific energy inputs and outputs in various scenarios.

Who May Find This Useful

This discussion may be of interest to those studying food production, energy economics, environmental science, and sustainability, as well as individuals curious about the energy dynamics of agricultural practices.

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?
 
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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.
 
on the other extreme we have beans
 
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.
 
Does it take 10 calories from fuel to produce 1 calorie in the form of ethanol derived from corn?
 
TheTechNoir said:
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.
 
Phrak said:
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.
 

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