Fasting One Day a Week:
Fasting One Day a Week Good for You?
Dr. Ben Kim
fasting one day a week good for your health? To answer this question, let's take
a look at what happens in your body when you begin to eat and drink nothing but
your cells use up the sugar that is in your bloodstream from your last meal or
beverage, your body has to find another source of energy for your cells. And the
first places that it turns to are your liver and your muscles. Both your liver
and your muscles store sugar in the form of glycogen, and when needed, glycogen
can be broken down to glucose, which all of your cells can use to produce energy
for their ongoing activities.
a water-only fast, your glycogen stores are depleted within about 24 hours, give
or take a few hours. After your glycogen stores are used up, most of your cells
begin burning fatty acids for energy - these fatty acids come from your fat reserves,
including fatty tissue that surrounds your organs.
groups of cells - your red blood cells and your brain cells - cannot use fatty
acids to fuel their energy needs. Your red blood cells and brain require glucose,
and once glycogen/glucose from your muscles and liver are used up, your brain
and your red blood cells get their glucose from two sources:
which is a component of your fat tissues.
your muscles - some of your muscle tissues get broken down, and the amino acids
from your muscle tissues are used to produce glucose for your brain and red blood
it's not in your best interest to rapidly eat up your muscles to meet the energy
requirements of your brain and red blood cells during a water-only fast. Your
body knows this, and somewhere between the 2nd and 3rd day of water-only fasting,
your liver begins churning out ketones, which during a water-only fast, come primarily
from the breakdown of fatty acids from your fat reserves.
your liver generates large numbers of ketones, your brain is able to use ketones
to fuel itself. At this point, only your red blood cells require glucose that
must still be derived from breakdown of your muscles, but with your brain no longer
dependent on breakdown of your muscles for energy, the rate at which your muscles
are catabolized will be such that your muscles are spared as much as possible
- this state is called "protein sparing" - it's a survival mechanism that is built
into human physiology to deal with times of famine.
back to the big picture, it should be clear that from about the 2nd or 3rd day
of a water-only fast, your body meets it energy requirements by burning through
your fat reserves.
the bulk of the toxins in your body are stored in your fat reserves, the longer
you fast on water only, the more fat you'll burn and the more toxins you'll eliminate
from your system.
is why we see elimination of lipomas, atheromas (accumulated waste in your blood
vessels), and other conditions related to toxin accumulation during a prolonged
another way, your body does not experience significant detoxification during the
first 12-24 hours of a water-only fast.
body begins to eliminate large quantities of toxins only after it begins to burn
your fat reserves at a rapid rate. And this doesn't happen until you've used up
the glycogen stores in your liver and muscles.
when you fast one day a week, you deplete the stores of sugar in your liver and
muscles, and you begin to break down your muscles - these are the main things
you accomplish during the first day of water fasting. Significant detoxification
only begins to occur if you continue past day one of fasting.
is not to say that there are no benefits to fasting one day a week, or that you
don't eliminate any toxins during a one-day fast.
are eliminating toxins with every breath that you take. And your body will always
increase its rate of ongoing detoxification whenever you get more rest and/or
eat less food, because less digestive burden and more physical rest always
mean more available resources for detoxification.
than fast one day a week on water only, I think it makes more sense to do a juice
fast one day a week, or even once a month. With a juice fast, you can supply your
body with enough nutrients that you don't have to deplete the sugar stores in
your liver and muscles, or break down a lot of your muscle tissue. At the same
time, because the nutrients in freshly pressed juices are so easily digested,
a one-day juice fast can ease digestive burden and enhance ongoing detoxification
to some degree.
let's be clear: the main benefit of a one-day juice fast is not significant
detoxificiation; it's a concentrated period of rest for your digestive organs,
and an opportunity for the organs that are responsible for ongoing detoxification
(liver, kidneys, skin, and lungs) to do a little extra health-promoting work.
things up, I would say that it's not good for long term health to fast one day
a week on water only. If you want to give your body a period of rest and intense
cleansing once in a while, it makes more sense to spend a day eating all raw fruits
and vegetables, or drinking nothing but freshly pressed juices.
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