- Fasting has become a very popular topic
over the last few years,
because it is fantastic for helping us lose weight,
but there are plenty of health benefits beyond this.
In this video, I'm going to take you through
the nine major benefits of intermittent fasting,
and I'm confident that once you know these,
you will want to make it a regular thing.
(upbeat music)
Hi, carb dodgers, 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, and fasting.
If that sounds good to you,
then make sure you subscribe to my channel,
so you get notified whenever I release new videos.
But why should you consider fasting at all?
Isn't it a bit unnecessary?
Why should we deprive ourselves of food?
Doesn't that seem a bit like we're punishing ourselves?
Surely it can't be good for us.
I've heard all of these comments and more in the past,
but the thing is fasting should be the normal.
Eating all the time is not normal.
We haven't always had access to an abundance of food.
And of course, many parts of our modern world still don't.
The Neolithic Revolution,
which was the wide scale transition of many human cultures
from a lifestyle of hunting and gathering
to one of agriculture and settlement,
really only got started approximately 10,000 years ago.
And in the grand scheme of human evolution,
that is absolutely nothing.
Humans did not evolve to eat all the time.
When our ancestors had to hunt for food,
not eating for extended periods of time was normal.
And even a generation or two ago,
we didn't have endless coffee shops, takeaways,
home delivery, supermarkets that are open 24 hours a day.
Typically, if we were lucky,
we had three square meals a day,
and we easily fasted for 12 to 14 hours each night.
But now the average person in the Western world
eats over a minimum period of 15 hours,
and many even longer.
We evolved to deal with fasting and feasting,
and we definitely haven't evolved to eat all the time.
So why has it become so common to eat frequently?
Well, we've already mentioned
about the 24 hour availability of food.
Well, who's behind that?
As usual, it's the food industry.
They want us to consume their products, and lots of them.
Clever marketing and easy access
has led us to believe that we have to eat
from the moment we wake up, eat all through the day,
then all evening, as we sit on the sofa,
or how else could we possibly cope?
We eat at our desks, we eat while driving,
we eat all all through the movies.
We even have our caramel latte while walking the dog.
Even the fitness and diet industry
has been completely taken over by food,
claiming you must eat five to six times a day.
You must fuel before, during, and after workouts.
And even the kids are having a sugary sports drink
at halftime in their football matches.
We do not need to eat like this,
and problems start to occur when we do.
We know that our bodies should work
in tune with our circadian rhythms.
And the term circadian comes from the Latin circa diem,
which means around the day.
It's our internal clock,
which regulates different bodily activities and functions.
The most well known is the sleep wake cycle
to match the normal rhythms of night and day.
But our digestive system
and the endocrine system release proteins and hormones
at timings to suit the normal wake cycle,
which should correspond with eating periods.
The sleep cycle should correspond to a fasting period.
These are easily disrupted
when we go against our natural biological clock,
and eat late into the evening
on over prolonged periods of time.
So the big question is, is switching back to a pattern
when we eat for shorter periods
increasing our time spent fasting going to improve our health?
Well, let me just share this quote
from a 2015 research paper.
"Several lines of evidence support the hypothesis
that eating patterns that reduce
or eliminate nighttime eating,
and prolong nightly fasting intervals
could result in sustained improvements in human health.
Prolonged nightly fasting may be a simple, feasible,
and potentially effective disease prevention strategy
at the population level."
Now a quick word about the research here.
Whilst there is a growing body of studies
being conducted in humans around fasting,
these studies are based on small groups of people.
Much of the data from larger studies is based on animals,
but it is believed that this is applicable to human health.
We hope.
Unfortunately, the majority of funding
for scientific research
stems from the pharmaceutical industry,
who have really very little to gain
from a drug free approach to health improvement.
That said, there are plenty of studies
looking at the effect of shift work on human health,
and shift work means a disrupted circadian rhythm,
and disordered eating patterns,
which evidently leads to an increased risk of obesity,
diabetes, cardiovascular disease,
and some forms of cancer over the longer term.
As normal, I'll put the links to the science
in the description down below.
So let's dive into the benefits.
Number one is weight loss.
I'm going to get this one out of the way first.
It's the one that many of you will be familiar with,
as it's one of the main reasons
that fasting has become so popular
over the last few years.
But it's important that we understand how it works,
because this will help us to understand
some of the other benefits we will discuss shortly.
Fasting lowers insulin levels.
Eating, especially sugar and carbohydrates,
causes our blood glucose levels to go up.
Our pancreas responds by producing insulin.
Insulin drives glucose out of our blood, and into storage.
When we have prolonged periods of going without food,
it enables our insulin levels to drop nice and low.
High levels of insulin keep us in fat storage mode,
low insulin levels mean we can use our storage fat
for energy, which is key for helping us to lose weight.
Extended periods of eating disrupts our appetite signaling.
Remember our circadian rhythm that I mentioned earlier?
And the hormones?
Well, this can get messed up,
so that we feel hungry much more often than we should.
Leptin is released by our fat cells,
and should function as the off switch to eating
when we are full.
However, too much leptin over time,
and we become leptin resistant,
where the brain then doesn't receive
the off signal properly, and so keeps stimulating us to eat.
It also leads to decreased energy expenditure,
as the fed signal isn't there.
And so we falsely think we're starving,
and need to conserve our energy.
Intermittent fasting can help to reset these hormones,
so that our appetite is better regulated,
and we naturally want to eat less, so aid weight loss.
Frequent eating negatively affects our gut microbiome.
Prolonged eating periods
don't suit the natural rhythm of gastric emptying
in our digestion.
Our digestive systems need rest.
The absorption of food, and in particular glucose,
is much slower towards the end of the day.
So you end up with raised glucose and insulin levels
for a longer period of time, which can lead to weight gain.
Again, prolonging periods of not eating,
and avoiding evening or nighttime eating
will help improve the of the gut microbiome,
as it has plenty of time for rest and recovery.
And then of course, there is straight up calorie reduction.
When you fast, you naturally consume less calories.
So whilst people do tend to eat more when they are eating,
it never quite seems to add up to the same.
From a practical point of view,
you could try to finish eating by seven or 8:00 PM,
and not eat again until seven or 8:00 AM is a basic rule
before you consider any longer periods of fasting.
Number two is diabetes type two prevention or reversal.
Now I already mentioned insulin in the last point,
but persistently raised insulin levels
lead to insulin resistance,
where the pancreas needs to produce more insulin
to have the same effect on blood glucose.
Eventually, the resistance can get so bad
that insulin can no longer maintain a healthy level,
and we end up with elevated blood glucose levels.
This is basically what type two diabetes is.
Periods of intermittent fasting
can dramatically improve our insulin levels,
and our insulin sensitivity can start to be restored
back towards normal functioning.
It really is incredibly powerful,
and many of my clients who reversed their type two diabetes,
and pre-diabetes combining intermittent fasting
with a low carb diet.
A word of caution here, though.
If you are already diabetic, and on medication,
then please consult with your medical practitioner first
before introducing a low carb diet or intermittent fasting,
as you may well need your medication adjusting.
Number three, may reduce the risk of cardiovascular disease.
Cardiovascular disease is mainly caused
by underlying chronic inflammation within our blood vessels.
This causes damage to the inner cell layer
of the blood vessels, the endothelium,
and the development of plaques,
which can lead to blockages of the blood vessels
within the heart muscle.
Angina, heart attacks, and within the brain, strokes.
Once again, elevated insulin levels are at work,
causing widespread inflammation and damage.
In addition to this,
fat cells themselves cause inflammation,
as they release proteins called cytokines.
Remember one of the hunger hormones
that I mentioned earlier, leptin?
Well, this too is inflammatory.
The beauty of intermittent fasting
is it enables all of this inflammation to be reduced,
thereby reducing the risk of cardiovascular disease.
Number four,
fasting may reduce the risk of Alzheimer's disease.
Alzheimer's disease is horrendous.
One in nine people over the age of 65 in the USA
has Alzheimer's dementia.
The rates here in the UK are slightly lower,
but it is becoming more prevalent
within our aging populations.
You might have guessed it,
but insulin resistance also wreaked its havoc in the brain.
The blood brain barrier can become insulin resistant,
which means not enough glucose
is able to pass from the blood into the brain cells.
Alzheimer's disease is known as type three diabetes
by many scientists,
as the underlying mechanisms are so similar.
This fuel shortage can be present many years
before we notice actual memory problems.
There is strong evidence
that the brain is able to use ketones for fuel,
instead of glucose.
Ketones are produced from the breakdown of fat,
and do not need insulin
to get across the blood brain barrier.
And so can bypass the problems with insulin resistance.
Ketones are produced when we fast,
as well as with a ketogenic diet.
So intermittent fasting may prevent brain degeneration,
and may possibly even improve symptoms
in those where they're already apparent.
Number five is improved sleep.
We've all experienced the discomfort
of trying to sleep when we've eaten a heavy meal
late in the evening.
Prolonged periods of eating
distorts the natural circadian rhythm of digestion.
We've mentioned this a few times already.
This has a knock on effect of causing poor quality sleep.
We know there's an association between poor sleep patterns,
and poor metabolism, leading to obesity, diabetes,
and cardiovascular disease.
So when you don't sleep well, it also makes you tired,
and more hungry, as well as grumpy.
And research has shown that people make poor decisions
about food when they're tired.
And so starts the vicious cycle of continuous hunger,
distorted hormones, poor sleep, and ultimately, poor health.
One of the standard pieces of advice we give out as doctors
for people who are struggling with their sleep
is don't eat too late at night.
Intermittent fasting,
or at the very least stopping eating earlier in the evening,
should help you to have a better quality sleep,
and break the cycle leading to poor health.
So let me know in the comments down below,
how late do you typically eat your last meal or snack?
Be honest.
Number six, fasting increases levels
of human growth hormone.
Human growth hormone is a naturally occurring hormone,
which helps to maintain, build,
and repair healthy tissue in the brains
and the other organs.
This hormone can help speed up healing after an injury,
and repair muscle tissue after exercise.
This helps to build muscle mass, boost metabolism,
and burn fat.
Human growth hormone production
naturally peaks at puberty, and decreases as we age.
However, we can make the levels drop more quickly
through behaviors such as poor sleep.
And yes, you've guessed it, by eating too frequently.
We need to try and increase the production of this hormone
to increase muscle growth, and prevent muscle breakdown.
It is so important to maintain muscle mass,
particularly as we age,
as losing muscle mass can lead to frailty,
and increased risk of falls and fractures as we get older.
The first section is considered the effect
of our hormones on metabolism,
and how the risk of diseases
associated with poor metabolic health can be improved,
and even prevented by intermittent fasting.
The next three benefits are all related
to the process of autophagy.
Although this is still connected to the hormones
we've already mentioned, as you'll see,
autophagy is the process
by which our cells get rid of damaged or unwanted parts,
and recycle them into new fuel or new proteins.
The term comes from the Greek word meaning self and eat.
And it is an essential process to ensure healthy functioning
of our cells, which constantly need regenerating.
Autophagy is switched on by fasting,
and turned off by eating.
It is linked to another cellular protein called mTOR,
which is the master regulator of nutrient signaling,
basically influencing other hormones
involved in the metabolism of our food.
MTOR is active in the presence of insulin,
and is linked to cellular growth.
It is suppressed by the presence of glucagon,
insulin's opposite number.
Glucagon is raised when insulin is low,
and therefore, enables autophagy.
You can guess that if insulin levels are always raised,
mTOR is overactive, and autophagy cannot happen.
Like all things, there needs to be a balance.
We need time for cellular clearance,
and a time for cellular growth.
So how does this relate to health specifically?
Number seven, fasting may help prevent some cancers.
Many cancers occur when the normal cellular processes
that regulate their growth become damaged,
leading to growth becoming uncontrolled.
If cells are unable to self-repair,
then cells can become dysfunctional.
This is made worse by overactivity of insulin,
leading to chronic inflammation, hyperglycemia,
obesity, and poor sleep,
all of which are associated with some cancers.
Once again, intermittent fasting
can help normalize hormonal function, increase autophagy,
and normalize periods of cellular growth and repair.
It is therefore possible
that intermittent fasting may help to prevent some cancers,
and could in certain circumstances
be beneficial alongside cancer treatments
to make them more effective.
Number eight, fasting may help prevent
some neurodegenerative disorders.
Now we've spoken about Alzheimer's disease already,
with the respect to insulin resistance in the brain,
but it's also thought that eating too frequently
may be involved in the buildup of abnormal proteins
that damage our brains.
In the brain of someone with Alzheimer's disease,
abnormal levels of amyloid proteins clump together
to form plaques that collect between neurons,
and disrupt cell function.
The brains of people with Parkinson's disease
contains abnormal clumps of proteins called Lewy bodies.
As we've discussed already,
cellular proteins need to be replaced.
And it is thought that when autophagy is unable to occur
due to the over stimulation of that protein mTOR
through the lack of fasting,
it leads to neurodegenerative conditions.
To quote one of the papers I've linked for you
in this description down below this video,
"Autophagy dysfunction is strongly implicated
in the pathogenesis of neurodegenerative disorders,
including Parkinson's disease and Alzheimer's disease."
So we have seen from our nine benefits
of intermittent fasting
that it can really help to normal hormonal control
of metabolism, cellular repair, and regeneration.
This enables us to have a lower risk of poor health,
helping us to live and age well.
And if you've started this video
skeptical about intermittent fasting, what do you think now?
Will you be giving it a go?
Let me know in the comments down below.
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Thank you for watching,
and hopefully I will see you in the next video.