Today’s guest post is
generously offered up by Craig Emmerich, husband to—and co-author
with—the queen of keto herself, Maria Emmerich. Enjoy!
When we consume macro nutrients, our bodies go through a
priority for dealing with them. This priority can be very useful in
understanding how our bodies work and how to leverage it for losing
The body doesn’t like having an oversaturation of fuel in the
blood at any time. It tightly manages the fuels to avoid dangerous
situations like hyperglycemia or blood glucose that is too high.
But it also manages and controls other fuels like ketones (beta
hydroxybutyrate or BHB levels) and fats (free fatty acids or FFA
and triglycerides) to keep them under control and not oversaturate
the blood with fuel.
It is like the engine of a car. You don’t want to give the
engine too much fuel and blow it up. So the body controls the
amount of fuels in the blood to ensure you don’t “blow up.”
To do this, the body will address the most important (or
potentially most dangerous) fuels first. It does this in a very
logical way—in reverse order of storage capacity.
Here is a chart showing the breakdown of oxidative
priority for dietary fuels.
Modified Source: Keto. By Maria and Craig Emmerich
Original source: Oxidative Priority, Meal Frequency, and the Energy
Economy of Food and Activity: Implications for Longevity, Obesity,
and Cardiometabolic Disease, Sinclair, Bremer, et al, February
The #1 oxidative priority is alcohol because
there is zero storage capacity for it. It makes sense that the body
would address this first, since it can’t store it anywhere and
too high blood alcohol means death.
The second oxidative priority is exogenous
ketones. These are ketone salts that raise blood BHB
levels. There isn’t a storage site for ketones either, so the
body must deal with this before addressing other fuels. That is why
exogenous ketones aren’t the best option when trying to lose
weight. They displace fat oxidation, keeping fat stored while it
uses the exogenous ketones as fuel instead.
The third oxidative priority is protein.
Protein is a bit different, as there is a limited storage space for
protein, but protein is not a good fuel source. It takes 5 ATP to
turn protein into a fuel (glucose through gluconeogenesis) and
another 2 ATP to burn in the mitochondria. Why would your body
expend 7 ATP for something it can do for 2 ATP by just burning
glucose or fat from your body? Protein is only really used as a
fuel when other fuels (glucose and fat) are not present and it is
forced to use protein. Protein gets preferentially used to
stimulate muscle protein synthesis. It builds and repairs lean
The next oxidative priority is carbohydrates.
It has a moderate amount of storage capacity at 1,200 to 2,000
The last oxidative priority is fat. This makes
sense, as there is a theoretically unlimited storage capacity for
fat. There are people with upwards of 400 pounds of stored body
fat, which represents 1.6 million calories.
Oxidative priority can help you understand what happens
when you put certain fuels into your body. If you are
drinking alcohol while eating carbs and fat, the carbs and fat will
primarily go into storage while the body deals with the elevated
To understand the power of oxidative priority take the case of
an alcoholic. Alcoholics will have very low A1c levels (in the 4s)
no matter what they eat! If they eat tons of carbohydrates they
will still have an A1c in the 4s because the chronically elevated
alcohol levels force the body to store all glucose while dealing
with alcohol, creating a low A1c. I am not recommending anyone
become an alcoholic to lower A1c level—but quite the opposite
So, what does this mean, and how can you leverage your
body’s biology to lose weight?
If you avoid alcohol and exogenous ketones, get a just
enough protein to support maintenance of lean mass (about 0.8 times
your lean mass in pounds for grams of protein a day), limit the
carbs and then reduce dietary fat a bit to force the body to use
more stored body fat for fuel you will lose body fat. When
you restrict carbs for long enough (4-6 weeks for most people) the
body gets used to using fat as its primary fuel (keto adapted).
This means it can burn body fat or dietary fat equally well.
Eliminating other fuels and keeping dietary fat moderate allows the
body to focus on body fat for fuel resulting in fat loss.
That is our bodies system for processing fuels coming in through
the diet. Leverage it for improved results and body
Craig Emmerich graduated in Electrical Engineering and has
always had a systems approach to his work. He followed his wife
Maria into the nutrition field and has since dedicated his time
researching and looking at nutrition and biology from a systems
perspective. Over the last 8 years he has worked with hundreds of
clients alongside Maria to help them heal their bodies and lose
weight leveraging their biology to make it easy.
Thanks to Craig for today’s keto insights, and thanks to
everybody here for stopping in.
Questions about dietary fuels and oxidative priority—or other
points keto? Share them down below, and have a great end to the
week. Take care, folks!