The keto diet has one goal: get the body producing ketones. From
this, all the health benefits you've heard of - from weight loss to
performance - trickle down. The question is...how do you get your body to
begin producing ketones?
First,
let's talk basics. Ketones are a fundamentally different energy source
than the carbohydrates and fats your cells typically use for energy. It
can take several days (or weeks!) of ketogenic, low-carb, high-fat
eating before the body starts to produce ketones. And the time it takes
to get into ketosis varies between individuals.
“Keto” comes from the word “ketogenic.” This is a scientific term meaning that the body is producing ketones from fat.
1 When blood ketone levels exceed 0.5mM, the body has achieved "
ketosis."
Ketosis can be naturally achieved two ways: through diet or fasting
(meaning the body is producing its own ketones), or also by consuming
products that raise blood ketone levels (like
HVMN Ketone or
ketone salts or MCT oils). Ketosis and ketogenic are two different things; a body in ketosis doesn't mean that body is ketogenic.
Ketogenic
means the body is producing its own ketones, which must happen through
diet or fasting.
This body is in ketosis because blood ketone levels are
over 0.5mM. Someone else may consume ketones through an external means
(called
exogenous ketones).
This body is also in ketosis because its blood levels are over 0.5mM,
but it's not ketogenic—because it's not producing its own ketones.
Simple enough, right?
Now that you know how to get your body into ketosis (through a low-carb diet / fasting or by taking a
ketone supplement), let's explore the different ranges of ketosis and how to start a ketogenic diet.
Ways to Achieve Ketosis
As
with all metabolic processes, the state of ketosis is a spectrum. Past a
threshold (which varies from person to person), even a small increase
in dietary carbohydrate intake can trigger enough insulin release to
take the body out of ketosis.
General target blood ketones levels are as follows:
- No ketosis: under 0.5 mM BHB in blood
- Low ketosis: 0.5 - 1.5 mM BHB in blood
- Moderate ketosis: 1.5 - 3 mM BHB in blood
- High ketosis: over 3 mM BHB in blood
- Pathological ketosis: over 15 mM BHB in blood
Let's explore how the body achieves ketosis.
Physiological Ketosis
The typical methods used to generate physiological levels of ketosis are fasting, the ketogenic diet, and consuming
exogenous ketones like
HVMN Ketone.
After
an overnight fast, a low amount of ketones (0.1mM - 0.2mM) can often be
detected in the blood. As the time spent fasting increases, blood
ketone levels slowly rise until a plateau at 8mM - 10mM of
beta-hydroxybutyrate
(or BHB, the predominant ketone body in the blood) has been reached
after many days. Scientist Hans Krebs described this plateau as
"physiological ketosis."
Fasting
long-term is unsustainable, so following a strict ketogenic diet can be
used to maintain a low level of continuous ketosis. Research suggests
blood BHB levels between 0.4mM - 1mM can be achieved while following a
ketogenic diet. Anecdotal evidence suggests it’s sometimes possible to reach higher levels.
Using exogenous ketones can raise blood ketones to a physiological level without the ketogenic diet or fasting.
The level of ketosis reached depends on the exogenous
ketone supplement used. Reported levels range from 0.6mM with a
ketone salt or a medium-chain triglyceride supplement, and up to 6mM with HVMN Ketone.
The
level of ketosis required for different physiological benefits is
unknown. For endurance sports, a higher level of ketosis (>2mM)
appears to be superior to lower levels. This is possible because ketones fuel athletes' muscles during a
workout. However, some other benefits of ketosis, such as reduced
appetite may be seen at much lower levels (0.5mM).
Pathological Ketosis
Sometimes,
the body starts producing ketones as a result of a disease (pathology).
This can lead to dangerous levels of ketones in the body, though these
high levels are very uncommon in healthy people following the ketogenic
diet.
Alcoholic ketoacidosis (AKA) is a result of chronic alcohol
consumption usually accompanied by malnutrition. AKA is characterized by
increased ketone production (levels > 15mM) via liver alcohol
metabolism, in conjunction with a mild elevation in blood glucose
levels. Symptoms include nausea and vomiting, fatigue, altered
breathing, and abdominal pain.
Diabetic
ketoacidosis (DKA) occurs most frequently in patients with type 1
diabetes. DKA is the simultaneous occurrence of high blood ketones (>
20mM), high blood glucose, and acidification of the blood. It develops
when insulin is absent, or insulin signaling is no longer functional.
This means the physiological state of starvation is triggered, even in
the presence of high blood glucose. As during starvation, lipolysis (fat
release) increases. This causes the liver to produce a high amount of
ketones and blood pH to fall (as ketones are an organic acid).
As
glucose levels are very high, the excess is excreted in the urine. This
draws water and electrolytes out of the body, causing dangerous
dehydration. Symptoms of DKA include nausea, vomiting, altered
breathing, abdominal pain, and unconsciousness. The rapid onset and
alarming nature of DKA is a reason why ketosis has a bad stigma in the
medical community.
You may be doing keto wrong.
There's
a ton of misinformation out there about the keto diet. We're on top of
the scientific literature. Be the first to read our commentary on the
research by subscribing.
Starting a Ketogenic Diet
The
keto diet is a moderate-protein, low-carb, high-fat diet. Its goal is
to get the body to produce ketones, which are then used an fuel source
for both the brain and the body. But because it's low-carb, high-fat,
the keto diet often gets confused with other diets out there.
What Makes Keto Unique?
Just
because a diet is low carb doesn’t mean it’s keto. The subtle
differences in macronutrients on keto make it unique (more on these
later). Keto isn't Atkins. Keto isn't paleo. Keto isn't high protein.
High fat intake is often a
concern on keto
because, for years, a low-fat diet was equated with fat loss. In Dr.
Atkins' 1972 book, "Dr. Atkins' Diet Revolution," he began to reshape
how we think about fat.
The pendulum of public perception continued to
swing in favor of diets higher in fat, thanks to the emergence of
influential writers and speakers such as Gary Taubes, Robert Lustig, and
Nina Teicholtz, and clinicians and scientists such as Professor Tim
Noakes, Dr. Jason Fung, and Professor Thomas Seyfried. The fear of fat
has only kept decreasing.
Usually,
keto is confused with Atkins. On Atkins, the initial aim is to restrict
the carbohydrate intake to less than 20g per day. This degree of
restriction is likely to lead to ketosis, although this is not an
explicit aim. Then, the diet reintroduces carbohydrates to a level “the
body can tolerate.”
9 There's also less restriction on protein compared to a true ketogenic diet: high fat, moderate protein, low carbohydrate.
Tips for Starting a Keto Diet
Don’t
try to start the diet gradually. If carbohydrate intake is
moderately-low, blood sugar levels may not be enough to fuel the brain,
and the presence of carbohydrate in the diet might still be enough to
stop the body from making ketones.
The main objective when
starting the ketogenic diet is to restrict carbohydrates to 20
digestible grams per day or less (this is what's considered a strict
ketogenic diet) and consume fat until you're satiated. Remember to
consume plenty of fiber as well. And regarding protein: stay at or below
0.45 grams of protein per day, per lb of body weight (1g/kg). If your
goal is to lose weight, aim for 1 gram of protein per kg of your target
weight.
Here are a few tips for when you're starting keto:
- Make
a keto meal plan. It’s a good idea to establish an eating plan before
starting the diet. Make a shopping trip to stock up on a range of foods
that are low in carbohydrates and high in fat
- Use an app to track macronutrient intake. Apps such as MyFitnessPal are great to get an idea of the macronutrients in common foods. There is also a range of special online keto diet calculators
- Search for a few keto recipes to adapt cooking methods. Due to the high-fat consumption required to get into ketosis,
it may be beneficial to change daily staples or cooking methods. You
could increase your intake of tasty foods such as coconut oil, heavy
cream, and cheese
- Make an approved list of keto diet foods and
eliminate carbohydrate-rich foods. It will be easier to follow the diet
by throwing out any foods to avoid. It’s recommended to check the labels
for hidden added sugars
- Consider starting a ketogenic diet with
a short period (16-36 hours) of fasting (consuming zero calories).
Fasting depletes carbohydrate stores and can accelerate ketone
production. Click here to read more about fasting protocols
- Gentle
cardio exercise (~30 minutes) or some short high-intensity intervals
(10-second sprints) can deplete carbohydrate stores and speed up ketone
production
Keto Diet for Weight Loss
The ketogenic diet can be used to help with weight loss.
Recently,
the number of positive keto diet reviews, and small-scale science
studies has increased. The rising popularity of the diet has led to a
demand for further randomized control trials to study its long-term
efficacy. A key reason why the ketogenic diet helps weight loss is that
it decreases hunger. This makes it easier to maintain a calorie deficit.
It is important to stress that the
overconsumption of calories will generally prevent weight loss, regardless of the macronutrient composition.
Cyclical Ketogenic Diet and Cheating on Keto
At
the moment, there is not a clear answer as to whether the benefits of
the ketogenic diet can be achieved by cycling on and off the diet. It’s
best to stick to the diet for one or two months minimum to see benefits.
It can take several days to get into ketosis
1 and 3-6 weeks to become “fat adapted.”
Some
research indicates ~40 days on the ketogenic diet interspersed with
periods of healthy eating with more carbohydrates (Mediterranean diet)
could maintain weight loss.
“Cheating,”
and consuming high-carbohydrate food, quickly stops ketone production
by the liver. It can then take a considerable amount of time for the
body to get
back into ketosis.
Time taken to get back into ketosis will depend on many factors
including, the amount of carbohydrates consumed, how adapted the body is
to produce ketones, activity level, etc.
However, cyclical
ketogenic diets are a promising area of scientific investigation.
Recently, scientists studied the effect of long-term cycling of the
ketogenic diet (one week on, one week off the diet) compared to a normal
diet in mice. Cyclical keto dieting reduced mid-life mortality and
increased health-span.
Measuring Ketone Levels
An
essential, objective way to see if you're in ketosis is to measure.
There are three main ways to test for ketones—in the blood, in the
breath and
in the urine—each
with its own benefits and considerations. The most accurate? Measure
levels of BHB in the blood. You can dive into our analysis of all three
methods
here.
Macronutrient Composition for Keto Diet Success
A
balanced macronutrient intake is essential for success on the keto
diet. Macronutrients are food groups humans consume in large quantities.
They provide the bulk of the energy to the body.
The primary macronutrients are carbohydrates, fats, and proteins.
The
macronutrient composition of a diet can be described using the mass of
each macronutrient, the ratio of macronutrients in the diet, or the
percentage of each macronutrient in the diet. The variety of
descriptions can make things a little confusing.
For example:
- A ketogenic diet contains about 5% of energy as carbohydrates.
- A ketogenic diet has a ratio of 2g - 4g of fat to every 1g of carbohydrates plus proteins.
- A classical ketogenic diet contains 20g - 30g of carbohydrate per day
Here
are some examples macronutrients based on foods you might eat every
day. Carbohydrates: bread, pasta, potatoes, cereals, sugary food
(sweets). Fat: oils (olive oil, coconut oil), butter, fatty cuts of
meat, brazil nuts, macadamia nuts, avocado. Protein: beef, chicken,
pork, fish, milk, cheese, yogurt, eggs.
Carbohydrates
The main
function of dietary carbohydrates is to be a source of energy. Some say
that dietary carbohydrates are not essential, as they can be made from
dietary protein and fat.
Carbohydrates
are biological molecules that contain carbon, hydrogen, and oxygen,
usually with a 2:1 ratio of hydrogen:oxygen. Carbohydrates occur as a
collection of single units (monosaccharides, e.g. glucose), two
molecules joined (disaccharides, e.g. sucrose), and chains of molecules
(oligosaccharides and polysaccharides).
When following a ketogenic diet, carb intake should be very low.
This
contrasts with the modern western diet (how many Americans eat), which
is high-carb: most dietary calories come from carbohydrates (and often,
processed foods). Consuming carbohydrates causes insulin release
(leading to higher insulin levels), which inhibits ketone production in
the liver and thus
ketosis. Therefore, monitoring and modulating your carbohydrate intake is an important part of following the ketogenic diet.
Dietary
carbohydrates replenish the stores in muscle and liver (glycogen). They
also maintain blood glucose concentrations to provide fuel for the
whole body—but most importantly for the brain. Blood glucose is easy to
measure using a handheld blood glucose monitor. Normal blood glucose
levels fluctuate throughout the day and vary between individuals.
Ranges of Blood Glucose levels for clinical diagnosis are as follows:
- Fasting: healthy = 4mM - 6 mM / 70mgDl - 110 mgDl
- Fasting: diabetic = ~ 7 mM / 125 mgDl
- 90 minutes post-meal: healthy = < 8 mM / 140 mgDl
- 90 minutes post-meal: diabetics = > 11 mM/ 200 mgDl
When
you’re following the ketogenic diet, key concepts are the total amount
of carbohydrates, the net amount of carbohydrates (accounting for the
accompanying fiber), and the speed with which carbohydrates raise blood
glucose (glycemic index). With a standard ketogenic diet, it’s
recommended to keep the total amount of carbohydrates limited to less
than 5% of energy intake.
Dietary
fiber is carbohydrate-based material from plants that is not entirely
broken down by the small intestine. Instead, it passes to the large
intestine, and either undergoes fermentation (which supports the growth
of beneficial bacteria),
or excretion.
Fiber is a significant part of a well-formulated
ketogenic diet. It helps to maintain gut health, and also increases food
bulk and helps with the feeling of fullness. Green and cruciferous
vegetables are rich in fiber and are helpful to include in a ketogenic
diet.
Depending on how complex the source of fiber is, it has
different assumed caloric values. One approach is to treat fiber as
having the same amount of calories per gram as carbohydrates: 4
kCal/gram. However, as a proportion of fiber is not digested, other
approaches use a lower value of 2 kCal/g. Digestion-resistant fiber does
not contribute to calorie intake, as it is not broken down.
Net
carbs refer to the mass of total carbohydrates, minus the total fiber,
which could be a better metric to judge carbohydrate intake because:
- Fiber is mostly digestion-resistant and so should not increase blood glucose.
- Studies have shown an increase in fiber does not affect blood ketone levels.
The
‘glycemic index’ is a scale that ranges between 1 and 100, and it
indicates how quickly food raises blood glucose after consumption. Pure
glucose is the reference and is set at 100 (meaning, raises blood
glucose quickly). Other foods have a comparatively lower value as they
raise blood glucose more slowly. Example values for the glycemic index
of food are white potato (~80), white bread (~75), apple (~35) and
peanuts (~15).
Glycemic load accounts for both the speed of
carbohydrate release and the total amount of carbohydrates in food. Food
can have a relatively high glycemic index (i.e. carrot = 47) but
because the total carbohydrate amount is low (carrot = 5g per serving),
the glycemic load of one serving is very low.
Protein
Proteins are large molecules composed of chains of amino acids. The functions of dietary protein are:
- Building structural and functional components of cells
- Conversion to glucose via gluconeogenesis
- Top up intermediates in other metabolic pathways, such as the Krebs Cycle
While it's possible for a protein to be used as a fuel, this isn’t its primary function.
When following a ketogenic diet, there must be a balance of sufficient protein to
maintain muscle mass.
If dietary protein exceeds 20% - 25% of calories, gluconeogenesis from
protein can stop ketone production. Initially, target a protein intake
of 0.8g - 1.2g per kilogram of body weight. This target balances the
need for protein against the chance of excess gluconeogenesis.
Some
individuals (such as strength or endurance athletes) may have higher
protein requirements. They might require a modified ketogenic
macronutrient ratio of 2:1 fat: non-fat (where 65% of energy is fat, 30%
is protein, and 5% carbohydrate) and can still be effective for
therapeutic ketosis.
Fats
Fat gets a bad rap. In
nutrition, fat is the dietary macronutrient made up of triglyceride
molecules. The main functions of fats in the diet are to provide
increased energy levels and makeup key functional and structural parts
of the human system.
But we often misuse the word “fat.” There’s a difference between fat in cells and different types of fat molecules:
- Adipose tissue: the tissue that stores energy as fats/lipid droplets inside adipocytes (fat cells). This is body fat.
- Adipocytes: individual cells that store fats/lipids
- Lipids:
the most general term forinsoluble and polar biological fat molecules.
The lipid class of molecules includes mono-, di- and triglycerols,
cholesterols, and phospholipids
- Triglycerides: a lipid molecule made up of glycerol (that acts as a backbone) joined to three fatty acid molecules
- Fatty acids: a molecule composed of a chain of carbon atoms bonded to one another with a carboxylic acid at one end
To be specific, our diet includes many sources of lipids.
Lipids
are digested and travel in the blood as triglycerides and fatty acids
before being used as a fuel, or stored by adipocytes in adipose tissue.
Dietary lipids undergo many tightly regulated metabolic steps before
storage in adipose tissue. Dietary fat does not equal stored body fat.
Triglycerides
are the most important source of energy in a ketogenic diet. They
account for > 70% of dietary calories. For those following a
ketogenic diet, it’s helpful to understand how the lipid source in the
diet is processed in the body.
Fatty acids can be saturated (no double bonds between carbons), or unsaturated (one or more double bonds between carbons).
Saturated
fats are relatively stable and tend to be solid at room temperature
(i.e. lard, butter, coconut oil). Historical guidelines recommended
limited the intake of dietary saturated fats because fat consumption was
thought to be associated with heart disease and high blood pressure.
However, emerging research has shown saturated fat can have beneficial
effects on blood biomarkers (i.e. increase healthy HDL cholesterol
levels).
Unsaturated
fatty acids can be further divided into monounsaturated fats (only one
double bond between carbons) and polyunsaturated fats (multiple double
bonds between carbons). The number of double bonds is important as it
determines how the fatty acid behaves both inside and outside of the
body.
They tend to be liquid at room temperature (i.e.
vegetable-based fats such as olive oil). Unsaturated fats are thought of
as healthier than saturated fats (also known as “healthy fats”).
Increased consumption of mono- and polyunsaturated fats have been linked
to improved blood biomarkers (i.e. lower blood triglycerides).
Eating enough unsaturated fats is important when following a ketogenic diet.
Increased fat consumption is not associated with cardiovascular disease.
Eating
a moderate amount of saturated fat is unlikely to be as harmful as
previously believed, and saturated fat consumption as part of a
ketogenic diet is unlikely to increase the risk of cardiovascular
disease.
Trans-fats are produced artificially when
hydrogen is added to unsaturated fatty acids in order to solidify it
and make it last longer. Because of associations with poor health
outcomes, these artificial fats had their generally regarded as safe
(GRAS) status removed in 2015 by the FDA. Avoid high levels of trans-fat consumption by eating a diet based around whole foods.
Essential
fatty acids are important to include in the diet because the body
cannot naturally produce them. This group includes poly-unsaturated
omega 3, omega 6, and omega 9 fatty acids.
It’s believed the
anti-inflammatory effects of essential fatty acids may have broad
benefits for health and performance. Oily fish, such as sardines and
mackerel, and seeds (i.e. flax) are good dietary sources of essential
fatty acids. If you don't get enough of these in your diet you can take a
supplement that includes fish oil, such as
Kado, from HVMN.
The
number of carbons in the fatty acid chain also has an important effect
on its metabolism. The carbon chain of fatty acids can be up to 28
carbons atoms long. If there are > 13 carbons in the fatty acid, it
is called a long-chain fatty acid, between 8-12 is a medium-chain fatty
acid, and under 5 carbons is a short-chain fatty acid.
The body
metabolizes fats differently according to chain length. Long-chain fatty
acids are absorbed and go from the gut into the lymphatic drainage
system and from there are released directly into the blood.
By
comparison, medium- and short-chain fatty acids do not go into the
lymphatic system. They travel in the blood from the gut directly to the
liver.
If a large amount of these short- and medium-chain fats are delivered
to the liver at once, this can trigger the liver to convert them into
ketones, even without dietary carbohydrate restriction.
Medium-chain fatty acids are highly ketogenic. They
can be found in natural sources
such as coconut oil or in an artificially purified form. However, for
many people, consuming a high amount of medium-chain fatty acids can
cause an upset stomach. This limits their use to raise ketones
artificially.
When integrating these concepts into a ketogenic
diet: target the majority of dietary calories as fat. Aim to include a
variety of fats from different animal and plant sources (i.e. red meat,
poultry, fish, dairy, olive oil, coconut oil, nuts, and avocados).
(To be continued next week)
This article is from HVMN, an organization that researches and presents articles
discussing health, nutrition and diet, among other topics related to
human optimization.
%20(1).jpg)
.jpg)
.jpg)
