Energy and Human Ambitions on a Finite Planet, 2021a

20 Adaptation Strategies 341
Example 20.3.16 What is the dietary energy factor for a diet in which
one-third of caloric intake is from red meat, 10% is from dairy/eggs,
<strong>and</strong> the rest is plant matter?
Setting f rm 0.33 <strong>and</strong> f d 0.10, we require that f v 0.57 in order
that all three sum to 1.0. Now using R rm 37, R d 8, <strong>and</strong> R v 1,the
dietary energy factor computes to 12.2 + 0.8 + 0.57 13.6 for red meat,
dairy, <strong>and</strong> vegetable matter, respectively. This diet requires more than
twice the production energy as a st<strong>and</strong>ard American diet.
It is possible to ab<strong>and</strong>on Eq. 20.1 <strong>and</strong> roll your own formulation following
similar principles. Rather than adopt the distributions from Table 20.2,
the technique can be customized to any diet for which energy factors
can be found.
Example 20.3.17 A diet that is 35% rice, 35% wheat, 15% corn, 10%
milk, <strong>and</strong> 5% chicken has an energy cost of 0.35 · 0.48 + 0.35 · 0.45 +
0.15·0.40+0.10·4.9+0.05·5.5 0.17+0.16+0.06+0.49+0.28 1.15.
This has not been normalized to R v 1 yet, 53 so we divide by the
aggregate 0.65 value for the plant energy ratio found in Table 20.3
to get a dietary energy factor 1.8 times that of a strictly plant-based
diet. Note from the sum that milk <strong>and</strong> chicken are the largest two
contributors, despite being a small fraction of the diet.
53: In other words, if performing the same
sort of calculation for 10% contributions
from each of the ten plant-based foods in
Table 20.2, the raw result would be 0.65.
The 10:1 input:output energy ratio mentioned at the beginning of this
diet segment may at first glance not square with the whole-diet energy
factors computed here (e.g., a factor of 6 for the typical American diet).
Missing is food waste. The U.S. produces 1.8 kcal of food value for every
1 kcal consumed [127]. This amount of waste may be hard to fathom, [127]: Eshel et al. (2006), “Diet, <strong>Energy</strong>, <strong>and</strong>
Global Warming”
but consider waste at restaurants, cafeterias, <strong>and</strong> grocery stores when
perishable items are not consumed before health st<strong>and</strong>ards suggest or
require disposal. Still, this is an area ripe for improvement.
20.3.5 Flexitarianism
Echoing Point #5 in the list in Section 20.3.1, it is worth pointing out that
energy <strong>and</strong> resource concerns are a largely quantitative game. One need
not become a strict vegan to affect energy dem<strong>and</strong>s substantively. For
instance, eating meat one meal a week, 54 <strong>and</strong> tending to stick to poultry
when doing so would drop the energy factor of Eq. 20.1 to a value so
near to 1.0 that the difference is of little consequence.
54: . . . out of about 40 meals
Example 20.3.18 For instance, if one meal per week, or about one
in 40 of your meals looks like the last column in Table 20.3—72%
plant-based <strong>and</strong> the rest poultry <strong>and</strong> dairy—what is the dietary energy
factor for this diet?
© 2021 T. W. Murphy, Jr.; Creative Commons Attribution-NonCommercial 4.0 International Lic.;
Freely available at: https://escholarship.org/uc/energy_ambitions.