- I was out having dinner with my wife
a couple of nights ago
and she asked me what my next video was on.
I said it's a video explaining the difference
between low carb and ketogenic diets,
to which she replied, "They're the same thing, aren't they?"
Which highlights the main reason that I'm making this video,
because these two terms are often used interchangeably
and they shouldn't be.
There are some very important differences.
All ketogenic diets are low carb,
but not all low carb diets are ketogenic.
It's kind of like all thumbs are fingers,
but not all fingers are thumbs.
The second reason is that
while I've been researching this video,
I've seen this topic explained very badly.
It's no wonder people are confused.
So let's do this properly.
(upbeat music)
Hi, I'm Dr. Dan Maggs.
I'm so glad you've landed on my channel,
which is all about achieving lasting weight loss
through low carb real food nutrition.
Today I'm going to be focusing on the difference
between low carb and ketogenic diets.
This video is not which of those is better,
what the pros and cons of each are.
I'm not going to be telling you which type of diet
is right for you, if either of them are,
but I will be making those videos soon,
so make sure you subscribe to my channel
if you're not already
so you don't miss those when they come out.
So, yes, both low carb diets
and ketogenic diets involve restricting
the amount of carbohydrates.
As a starting point,
let's consider what most people in the Western world eat
on a daily basis.
It's going to be a combination of all sorts of bread,
rice, pasta, some protein, maybe not enough.
And if they've been listening
to what our governments have been preaching
for the last 50 years, not very much fat.
It varies quite a lot from person to person
and from country to country,
and clearly not everyone is following
their government's advice to the letter.
But broadly speaking,
the standard western diet is upwards of 250 grams
of carbohydrate per day, per person,
and often considerably more.
And as many of us learn at school,
but most of us have forgotten,
is that all of the starches in the bread, rice,
and pasta break down into glucose once they're in the body.
Glucose, which is commonly called the blood sugar,
can be used by cells all over the body for energy.
It can also be stored as fat.
Fat cells turn excess glucose into fat for storage.
Let's compare that to a low carbohydrate diet,
which, as you probably can guess,
aims to reduce the amount of carbohydrate consumed.
If you're consuming less carbohydrates,
you'll end up with less glucose in your blood,
and therefore your pancreas will produce less insulin.
The reason that is important
is because insulin is our main fat storage hormone.
It's what triggers those fat cells
to take up the glucose and store it.
That's why doctors,
whenever we start anyone on insulin injections,
we always warn them that the main side effect
is weight gain.
Having lower insulin levels allows us
to actually use our fat stores for energy
rather than simply keep adding to them.
So how low is low carb?
There's no universal definition
of how low a low carb diet should be.
Lots of scientific papers use less than 130 grams a day,
but if you read around the internet,
you're going to find figures quoted from anywhere
between 100 to 150 grams a day.
So that's around half of the amount of carbohydrates
when compared to a standard diet.
But what does a low carb diet look like?
Well, in practice,
that means you're going to be significantly reducing
your intake of bread, rice, pasta,
basically all of those white or beige foods.
Importantly, you're going to be significantly reducing
your intake of refined sugars.
And you can pretty much eat all vegetables
on a low carb diet,
but you're going to be wanting to manage the portion sizes
When it comes to starchy vegetables like potatoes.
Similarly, you're going to be limiting
but not eliminating fruit.
Because we're cutting back on carbohydrates,
generally, your protein and fat consumption
will go up a little bit,
and our bodies tend to adapt
to a low carb diet quite quickly and easily,
and you won't usually get any side effects
when restricting carbohydrates to this kind of level.
But there is an important safety point.
If you're diabetic and on medication
to lower blood glucose,
you should always consult your doctor
before starting a low carbohydrate diet,
as you run the risk of dangerously low blood glucose levels.
Now, unfortunately,
not all doctors are comfortable adjusting the medication
for low carbohydrate diets.
So I've linked to a useful paper down below
that you can give to your doctor
that basically tells them how to do it.
Let's look at the ketogenic diet,
or sometimes called the keto diet.
If we restrict carbohydrates more aggressively,
we'll get to a point
where we're no longer consuming enough glucose
to meet our body's basic needs.
Now, running out of glucose like this isn't really something
that most people in the modern world
have to concern themselves with.
Most of us have food security
and an adequate supply of carbohydrates.
But running out of glucose was a frequent challenge
for our hunter gatherer ancestors.
Fortunately, we evolved our way around it
and we can simply switch to an alternative fuel source.
When your body is running low on glucose,
your liver will begin to produce a fuel called ketones,
which it makes from fat.
This can be the fat that we are consuming
or the fat that it's stored on our bodies,
which as you can imagine is incredibly advantageous
for those of us who are looking to lose excess weight.
During the process of turning fat into ketones,
your liver also produces some glucose,
so your blood glucose won't drop completely,
even if you stop eating carbohydrates altogether.
Once ketone levels build up in your blood,
you've entered a metabolic state called ketosis.
The majority of the cells in your body
will happily run on ketones as their main source of energy.
For example, after three to four days
of being on a ketogenic diet,
75% of the brain's energy source is from ketones.
So the key thing that defines a ketogenic diet
is that it causes the body
to enter the metabolic state of ketosis.
In order to get into ketosis,
you must be consuming a very low level of carbohydrates.
So we can consider that ketogenic diets are a subcategory
of a low carbohydrate diet.
All ketogenic diets are low carb,
but not all low carb diets cause you to enter
the metabolic state of ketosis.
For the sake of simplicity,
from this point onwards, when I talk about a low carb diet,
I mean low carb diets that are not ketogenic.
It's ketosis, not ketoacidosis.
Now, I need to make an important distinction here.
It's important that we don't confuse ketosis
with diabetic ketoacidosis,
but it often is confused given the obvious similarity
in the name, even by doctors.
It's possible to have dangerously high levels of ketones
in the blood.
This is a condition known as diabetic ketoacidosis, or DKA.
DKA is a serious life-threatening complication
of Type 1 diabetes and less commonly Type 2 diabetes.
This is the reason I think many doctors freak out
when they hear keto anything.
All doctors know only too well that a patient
in diabetic ketoacidosis is critically unwell,
and honestly some of the sickest patients we ever treat.
So doctors are understandably jumpy
at the very mention of the word.
The key difference is that patients in ketoacidosis
not only have very high levels of ketones in their blood,
way higher than we'd ever get on a ketogenic diet,
but they also have very high glucose levels.
When we compare this to somebody who is in ketosis
due to diet, we find normal levels of glucose
and moderately raise levels of ketones.
Going from this to ketoacidosis isn't possible,
because if we consume carbohydrates
to raise our blood glucose levels,
we'd stop producing ketones.
So how much do we need to restrict carbohydrates
to get into ketosis?
Well, I'd love to give you an exact figure,
but the truth is that it varies from person to person.
It can vary based on your activity levels.
It can vary based on your genetics.
It can vary based on your physical size.
Clearly, someone who is six four
is going to have different needs to someone
who is five foot one,
but generally speaking,
we're looking at somewhere between 20
and 50 grams of carbohydrate per day.
Fortunately, it's quite easy to find out
if you're in ketosis.
We can measure the levels of ketones directly
with a simple finger prick blood test.
You'll also pass some ketones out in your urine,
where we can measure it with dipsticks.
I've made a video all about the different methods
of testing ketones levels, which I'll link to up here.
So what does a ketogenic diet actually look like?
Well, most fruit and vegetables are restricted,
starchy vegetables,
typically the ones that grow underground, like potatoes,
are completely eliminated.
Above ground vegetables like cauliflower, broccoli,
cabbage, lettuces are generally fine,
because they're very low in carbohydrates.
Most fruits, other than berries,
which are very low in carbohydrates, are also gone.
You'll need to focus on consuming
an adequate amount of protein for your body.
Again, that will vary based on how active you are.
And that's much the same as on a low carbohydrate diet.
The big difference is that when you cut back
on carbs so much,
you need to replace those carbohydrates with fat.
Importantly,
and this is something that I see explained incorrectly time
and time again,
it's not the adding of the fat that causes the body
to go into ketosis,
it's the restriction of the carbohydrates.
You go into ketosis if you just stop eating altogether.
The increased fat consumption
is to help you feel full after a meal.
It's not there to trigger ketosis.
So a ketogenic diet is usually described
as a very low carb, moderate protein, higher fat diet.
But doesn't eating fat make you fat?
Well, there is this common misconception
with the ketogenic diet
that you're just spooning fat into your mouth all day,
eating bacon and cheese and nothing else.
Thank you, Instagram.
But no, it's because ketones actually inhibit hunger
and trigger a reset on the feedback systems
that tell our brains to stop eating when we're full.
Now, we don't fully know the mechanisms by which this occurs
and more research is definitely needed in this area.
But people who are in ketosis
therefore naturally restrict their food intake
without the need for counting calories.
The experience of hunger on a ketogenic diet
is radically different.
Most people will drop from eating three meals a day
plus snacks to two meals a day,
or even one meal a day without really feeling hungry.
But a ketogenic diet can cause some side effects.
I mentioned earlier
that a low carbohydrate diet is generally well tolerated
by the body.
But with a ketogenic diet,
there are a set of transitional symptoms
that are collectively known as keto flu.
These occur when our bodies are simply not used
to being in ketosis.
For many of us, the only time we've ever spent in ketosis
is when we've been unwell and not able to eat.
It's important to note that side effects are to be expected
and are not a sign that ketogenic is not right for someone.
All that is happening is there's a drop in insulin levels
as a result of carbohydrate restriction,
and that means the kidneys lose some fluids
and electrolytes.
Thankfully, these side effects are usually able
to be minimized by focusing on hydration
and electrolyte replacement.
There is a document which you can download free
from my website which takes you through
how to easily manage the side effects of ketosis.
I'll leave a link to that in the description down below.
So both low carb diets
and ketogenic diets are low in carbohydrates,
but the ketogenic diet is very low and,
therefore, is higher in fat.
A ketogenic diet is defined by the metabolic state
of being in ketosis.
There are some more transitional symptoms
with a ketogenic diet,
but these can be easily managed.
And a ketogenic diet is by its very nature more restrictive
than a standard low carb diet.
But in some ways, that makes it simpler.
Some people love the clarity of being able
to test their ketone levels and say," Yes, I'm in ketosis."
But given that our governments have been pushing
a low fat message for pretty much the last 50 years,
it's natural that some people have safety concerns
about the additional fat you need to consume
on a ketogenic diet.
So I made a video earlier on this year,
which is called "Is Keto Safe?"
which addresses in some detail all of the safety concerns
that people commonly have around the ketogenic diet.
I'll link out to that at the end of this video.
I'm going to be doing a follow up to this video
in the next couple of weeks,
where I'm going to look at keto versus low carb,
which is better?
So make sure you subscribe to my channel
so you don't miss that one.
Have a great day.