Ketogenic Diets or ‘Keto-diets’ are becoming popular... again.
This is not a new idea or trend. It was very popular in 2009, and back
in 1996 (I’m starting to think diets have a twelve to fifteen year
Ketogenic diets are based on the idea of Ketosis - Ketosis is a state
you body enters when you quickly move into burning predominately fat as
When fatty acid oxidation is ramped up quickly, your liver can’t keep up
and some of the fatty acids are ‘incompletely burned’ leaving ketones as
【Carbon Explanation: Remember that Fatty Acids are long chains of
Carbon, and when we are using fat as a fuel we are simply cutting a
carbon off the chain and then move that carbon out of our bodies through
our breath as carbon dioxide. When our needs outweigh the speed we can
‘cut’ these carbons, we get lazy and start cutting at every third or
fourth carbon, creating carbon ‘fragments’ called ketones.】
Luckily we can easily use these ketones as a fuel. In fact, ketones
become the preferred fuel in many tissues, especially your brain.
【Carbon Explanation: We are still able to break ketones down to create
carbon dioxide which we then exhale.】
You start to enter Ketosis somewhere between 16 and 20 hours of fasting,
and it continues to increase the longer you fast. Then after about three
weeks, your body is fully adapted to fat and you go back to burning
predominantly fat as a fuel.
In summary - Ketones are produced when fatty acids are being used as a
fuel at a rate that is quicker then we can handle, leading to the
incomplete breakdown of fatty acids and the creation of ketones. Ketosis
is temporary as we eventually are able to increase our ability to fully
use Fatty Acids as a fuel source, Ketosis typically lasts two to three
weeks, depending on the person.
Ketosis is a Hallmark of prolonged fasting. However, since most people
don’t want to fast, there are also Ketogenic diets based on consuming
And here is the focus of this email - Ketogenic Diets and their use for
Ketogenic diets are Low carb diets (usually under 50 grams per day),
that are also low (ish) protein diets - typically recommending under 100
grams of protein, the rest of the diet is Fat.
Upwards of 70% of your daily calories come from Fat when you are on a
People either Love or Hate ketogenic diets.
Our main concern is - Do they somehow create BETTER or MORE fat loss?
For weight loss we know our main concern is non-water weight leaving the
body. In other words, carbon loss.
Since being in ketosis is the result of a high level of fat burning, we
know when you are in ketosis the carbon lost through our breath are from
fat. So if we are interested in Fat Loss (which most of us are) being in
ketosis is a good indication you have temporarily hit a maximal rate of
I have not seen any evidence that being in ketosis increases the amount
of CO2 you expire. To the best of my knowledge you don’t breathe heavier
or harder when you are in ketosis…
Based on the lack of change in expired CO2 your weight loss will remain
more or less the same, with the following possible exception.
When you are in Ketosis you also breathe out ketones. You also lose
ketones through your urine. The amount is small, but these are still
additional carbons escaping your body that you would otherwise not be
【Carbon Explanation: During Ketosis there is a small extra amount of
Carbon that leaves your body, however the relevance is most likely very
The only other possible explanation for increased non-water weight loss
would be an increase in carbon loss through some of the fat you are
eating not getting absorbed. However this has not been reported in any
Bottom line is that being in Ketosis ensures that almost all the carbon
leaving your body comes from fat. However there is the main difference
between fasting and a high-fat ketogenic diet…
With fasting we know the carbons are coming from your body fat, since
there are no other fat sources. With a ketogenic diet the Carbon will be
from a mix of body fat and the fat you are eating.
You are burning a maximal amount of fat, but it is a mix of fat from
your body fat, and fat from your diet.
In other words you may be burning just as much fat as when you are
fasting, but the amount of fat you are burning that was once body fat
may be smaller.
The only other weight loss benefit of a ketogenic diet is the amount of
food you get to eat while still losing weight…
Remember that Carbohydrates are roughly 40% carbon, while fat is roughly
This means 2,000 Calories worth of carbohydrates contains roughly 200
grams of Carbon, while 2,000 calories worth of fat contains roughly 175
grams of carbon.
So someone on a ketogenic diet may be surprised that they can eat a
little more than they thought they could while still losing weight...
this isn't magic - It's carbon
Bottom line: We are all losing weight every minute of every day. As long
as the carbon coming in is less than the carbon going out, ANY DIET will
allow for weight loss. Some diets allow for more of that weight to come
from body fat than others. If the carbon balance is correct, a ketogenic
diet will allow for weight loss, and for much of that weight to come
Your friend and Advocate,