- So many supposedly credible sources of health information
repeatedly insist that carbohydrates
are an essential part of the human diet
and they're all wrong.
We must address this misinformation
because many people can benefit
from low or very low carb diets.
Those people shouldn't be discouraged
because they think they're missing out
on something they need.
In this video, I will explain
why the answer to this question should be a flat no.
So let's get started.
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Hi Carb Dodges, I'm Dr. Dan Maggs.
I'm so glad you've landed on my channel
which is about achieving lasting weight loss
through low carb real food nutrition.
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So why do these people think we need carbs?
The main reason given is that we need carbs for energy
but there are a few other points people raise too
like we need carbs for thyroid function and gut health
and because of all the other nutrients that come
along with carbohydrate-based foods.
I'm going to be addressing all of these in this video,
but first, let's get clear on the question.
Do we need carbs?
Let's briefly clarify what we mean
when talking about carbohydrates or carbs for sure.
Carbohydrates are the sugars, starches, and fibers
found in our foods.
There are three single sugars:
glucose, sometimes known as the blood sugar,
fructose, sometimes called the fruit sugar,
and galactose.
Galactose is quickly converted into glucose
so we can think of it as glucose.
We've got some double sugars:
sucrose, better known as table sugar
is glucose and fructose joined together
and that gets quickly broken down when we consume it.
And lactose, the milk sugar,
is glucose and galactose so it all ends up as glucose.
Then there are starches.
Starches are long chains of glucose molecules
linked together.
It's how plants store glucose.
Bread, rice, pasta, and potatoes
are examples of foods that contain starches.
These chains all get broken down once they're digested
and so it all ends up as glucose.
So I find it's really helpful
to think of starches as just concentrated glucose.
Finally, we have fiber.
Fibers are also link chains of glucose.
However, we cannot digest these
due to the slightly different way they're linked together.
Typically, fiber comes from the cell walls of plants
called cellulose.
Some animals such as cows
can break down these cell walls for nutrition.
We call these animals ruminants.
So now we're all clear on what carbs are,
let's look at the other part of the question.
Do we need carbs?
To need something implies that it's necessary,
that it's required because it's essential.
For example, we need to breathe air
and we need to drink water.
To need something is not the same
as it being either important, desirable, or nice to have.
In the world of nutrition,
we have what are known as essential nutrients.
These are nutrients that we must consume
in sufficient quantities to remain healthy.
Put another way,
insufficient amounts of essential nutrients cause disease.
You'll be familiar
with some of these deficiency diseases.
A lack of iron causes iron deficiency anemia.
A lack of B12 also causes anemia
but can also cause neurological problems.
Iodine deficiency causes thyroid problems
which is why many countries put iodine in salt.
And I'm sure you all learned in school
that a lack of vitamin C causes scurvy,
the scourge of sailors for thousands of years.
These are all examples of micronutrient deficiencies,
and micronutrients are the vitamins and minerals
that we only need in relatively small amounts
but we do need them.
They are essential nutrients.
But we can also have macronutrient deficiencies.
The three main macronutrients
are proteins, fats, and carbohydrates.
We need protein.
Specifically, we need certain amino acids
which are the building blocks of proteins.
20 amino acids make up the proteins in human bodies
of which we need to consume nine of these.
They are therefore termed essential amino acids.
We can make non-essential amino acids in our bodies
and don't need to consume them.
Mild protein deficiency leads to muscle wasting,
brittle bones and a reduced ability to fight infections.
Severe protein deficiency is rare in the Western world
but sadly common in developing countries
and presents as diseases called marasmus and kwashiorkor.
We can become deficient in fats too.
We need to consume both omega-3 and am omega-6
fatty acids.
Fats, therefore are essential.
People with fatty acid deficiency develop fatigue,
poor memory, dry skin, heart problems, mood issues
and poor circulation.
Deficiency is rare, but it can occur in medical conditions
that stop people from absorbing fats.
It can also occur in those following
extremely fat-restricted diets.
So that brings us to the final macronutrient:
carbohydrates.
There's no such thing as carbohydrate deficiency.
Other than a few transitional symptoms
when we first eliminate carbohydrates,
no long-term deficiency illnesses
result from carbohydrate elimination or restriction.
Therefore, we don't need carbohydrates.
It's as simple as that.
So why do people think that carbs are essential?
Well, there are several common reasons that people give.
We need carbs to provide our bodies with energy
is the most common mistake that I see reported.
No, we don't need carbohydrates for energy.
People who tell us this
have an incomplete understanding of metabolism.
The absence of carbohydrates usually occurs in two ways:
fasting and starvation
or by eliminating carbohydrates from the diet,
pretty much just consuming fish, eggs, and meat,
what some people would call a carnival diet.
And it's important to understand
what happens when we stop eating carbohydrates.
Firstly, we start burning more fat.
We're always told that fat is very high in calories.
It's one of the nonsense arguments people use
to explain why eating fat is bad,
but by the same logic,
that makes it an excellent fuel source for our bodies,
especially for those of us who are carrying around
a bit extra.
When we reduce or eliminate carbohydrates from our diets,
we also reduce the production of insulin,
our fat storage hormone.
This low insulin state
creates the ideal metabolic conditions
for us to burn fat as fuel.
Most of the tissues in the body can burn fat for fuel,
with the brain being the major exception to this.
Next, we start producing ketones.
Ketones are an alternative energy source
produced in the liver,
either from fat we consume or fat that we've got stored.
Ketones indeed are an excellent source of energy
for the brain.
They're also a cleaner burning fuel,
producing fewer free radicals than when we burn glucose.
Now, fats and ketones can supply up to 90%
of the body's energy needs,
but where does the other 10% come from?
Well, it comes from glucose.
Yes, the burning of glucose is dramatically reduced
because our bodies have significantly increased fat burning
and introduced ketones as a new fuel source.
It's important to remember that
just because somebody isn't consuming carbohydrates
doesn't mean there isn't any glucose in our bodies.
Even when we're well adapted
to burning fat and ketones as fuel,
which can take weeks to months,
we don't eliminate glucose as a fuel source altogether.
Some cell types are dependent on glucose for fuel
because they lack mitochondria,
and whilst the brain can use ketones for most of its energy,
it may still have some requirement for glucose.
And this begs the question,
where does this glucose come from
if we are not eating carbohydrates?
Well, it comes from a process called gluconeogenesis,
which is a long and complex word that means
make new glucose.
Both fats and protein can be broken down into glucose
by the liver.
So even though some tissues require glucose,
this need can be met by glucogenesis
rather than carbohydrate consumption.
Even in severe starvation,
blood glucose levels are sustained
at the lower end of the normal level.
So no, we don't need carbohydrates for energy.
Our bodies can cope remarkably well without them
even under the stress of significant exercise.
I see a few other arguments as to why carbs are essential.
Do we need carbs for thyroid function?
The blood level of active thyroid hormone T3
will typically fall between 30 and 40%
in the first few weeks when carbohydrates are restricted.
So you can understand why some say
cutting carbs causes thyroid issues.
But this reduction in hormone levels
isn't accompanied by any of the signs or symptoms
you'd expect from someone suffering from low thyroid levels.
What is happening is there is an improvement
in the sensitivity of our tissues to the thyroid hormones.
This is a healthy response and not an illness.
So no, we don't need carbs for thyroid function.
Do we need fiber for bowel function and gut health?
If carbs are non-essential
and fiber is a form of carbohydrate,
then fiber is non-essential, right?
Yes, you won't get any deficiency from not eating fiber.
Now, fiber is controversial
and many people regard fiber as healthy,
but is there really any high-quality evidence
to support that?
There is evidence that high fiber diets
are harmful to some people.
This month, a paper published in Nature
showed a high-fiber diet makes rheumatoid arthritis worse.
And I'm not going to get into the debate
over whether fiber is or isn't a good thing in this video
but I recommend you watch an excellent video
by Dr. Zoe Harcombe, which dives into this topic in depth.
I'll link to that up here and in the description
along with some other interesting articles
about fiber and ketosis.
What I'd say about fiber is that at best,
it falls into the category of desirable for optimum health
rather than essential.
Do we need carbs for the other nutrients that carbs contain?
One of the common arguments for consuming carbohydrates
is that we need the other nutrients
that go along with carbohydrates,
particularly in plant-based foods.
There are numerous health promoting compounds
called phytochemicals that can be found in plant-based foods
as well as vitamins and minerals.
You'll find many strong arguments
to suggest that we should consume plant-based foods
for this reason.
But there is also the argument
there is a lot of bad stuff in plant foods.
Plants, after all, have natural defenses
to stop them from being eaten or prevent diseases.
They haven't got the luxury of running away as animals can.
They produce proteins such as lectins to stop these attacks
and we've been selectively breeding plants
to become more disease resistant
and have been increasing the concentration
of these proteins.
If you've previously been under the impression
that because it's plant based, it's always good,
then I recommend you check out a fantastic talk
about lectins by Dr. Paul Mason,
which may change your mind and I'll link to that up here.
So hopefully we've cleared up the confusion.
There's no inherent need
for the body to consume carbohydrates
so you don't need to be worried about
missing out on anything for this reason
if you're considering starting a low carb diet.
And remember,
unless you're considering an exclusively carnivorous diet,
you'll still consume some carbohydrates.
Even a strict ketogenic low-carb diet
still contains some carbohydrates.
One of the most popular videos on my channel
talks you through the 16 best low carb vegetables to eat
on a low-carb diet,
which you might like to watch next
and I'll leave a link to that on the screen.
Thank you for watching.
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