What Is
Intermittent Fasting?
Intermittent fasting is
a nutritional practice that is in vogue. This consists of spending long periods
of time fasting, that is, without ingesting anything but water.
Later I will explain
how it works and how it has to be carried out, but first I would like to tell
you what not many people know, and that is where all this intermittent fasting
comes from.
What Is
Autophagy?
The intermittent
fasting diet is a dietary adaptation resulting from the discovery made by the
Japanese Yoshinori Ohsumi. Yoshinori is a Nobel Prize winner in medicine,
thanks to the conceptualization of autophagy.
Autophagy comes from
Greek and means “self-eating”. Autophagy is a recycling process that our own
body seems to have, according to which, simply put, the cells of our own body
feed on other less healthy cells. This only occurs in conditions of fasting or
energy deficiency, as it is as if we were "feeding on ourselves".
How Much
Weight Loss Is Achieved with Intermittent Fasting?
Intermittent diets are
based on the concept of intermittent fasting and autophagy. This measure, which
in principle was focused as a measure to care for and protect health, many
people confuse it and use it as a way to lose weight quickly.
It is true that, by
means of a diet of intermittent fasting we can lose weight fast, although later
I will explain the counterpart to this.
When we eat, especially
when we take carbohydrates, it happens that our glucose levels rise (blood
sugar). Glucose is our main source of
energy, and it is thanks to it that we can feel more vital after a meal or
intake.
After a while, insulin
appears and begins to regulate these blood sugar levels. Thus, decreasing what
we call our glycemic index.
Insulin, in other
words, is as if it came to mediate and to say: "okay, we already have
enough energy (blood sugar), we are going to use this one, and we are going to
save this one for what is to come".
In fasting conditions,
insulin is nowhere to be found. Its absence implies that our organism
understands this as meaning that it must begin to obtain energy from other
places. I imagine that you are already getting an idea of where it is going to
get it.
Indeed, from fats. This
is when what we call the "fat burning" process begins, as long as we
have sugar in our blood our body will not consume the reserves.
So, what, go through
periods of fasting does help to lose weight, as we are forcing our body to
enter into a state of ketosis. (feeding on its own fat). This is the basis of
another of the famous fad diets: the ketogenic diet.
How Do I Know
When I Am Losing Weight?
This is something I am
tired of repeating, but I see that it is necessary: having lost weight does not
mean losing weight.
When you make a drastic
change in your diet, many things can happen, some of them: hormonal changes,
retaining more or less liquids, etc.
The only way we can
know if what we are doing is really working and what it is working for, is to
measure our body composition.
It may turn out that we
are very happy to have lost weight, but what has happened is that we have lost
muscle mass, for example.
How can we know this?
The only way is to use a Bioelectrical impedance scale. Bathroom scales are
useless, or of very little use. Neither are the cheap fake Bioelectrical
impedance scales that are advertised on some sites. These do nothing more than
give us statistics, but they do not make a real measurement.
How Many
Kilos Can Be Lost with Intermittent Fasting?
There is no way to
predict how many kilos can be lost with intermittent fasting. If someone
assures you that you are going to lose, I don't know, 10, 15 or 20 kilos doing
the intermittent fasting diet, be suspicious. This will depend on each person,
their metabolism, the starting point at which you are ... and a very long
etcetera.
How Many
Kilos Are Lost in A Week of Intermittent Fasting?
This is a question I
come across quite often and the answer is...there is no answer. At least not a
single one.
If someone assures you
that you are going to lose X kilos in a week doing intermittent fasting, they
are deceiving you. Each body responds in a different way, and this will vary
greatly depending on what your current basal metabolism.
A person with obesity
will not lose the same as a person with normal weight.
The Best Diet
to Lose Weight?
Earlier I told you
about a counterpart of the intermittent fasting diet, and the time has come to
tell you about it. It is true that fasting contributes to fat loss. However, it
is more than proven that the best way to lose weight and lose weight is to do
it progressively and steadily.
For the body, fasting
means to be in alarm. In prehistoric times, eating was not something that was
going to happen for sure. So, what I have told you that the body is able to do,
was essential for survival.
The thing is, what also
happens in these conditions, is that the body prepares itself to absorb and
retain everything that comes. When we fast, we are telling our body that it is
possible that we are going through a time of famine or food unavailability. So,
when we eat again, it should grab and release as little as possible.
This is called the
rebound effect, and is something that often happens when we lose many kilos
suddenly and then go back to eating normally. If your plan is to do an
intermittent diet or intermittent fasting diet to lose weight fast, I do not
recommend it at all. In fact, many people when they abandon this diet get very
scared when they suddenly find that they start to put on weight for no apparent
reason.
On the contrary, if
your goal is to make intermittent fasting a way of eating, this can be an
interesting option. However, you should always consult with your doctor and
study with him your particular case.
Types of
Intermittent Fasting
There are several types
of intermittent fasting. Some are based on a weekly periodicity, for example:
spending two whole days a week in fasting, consecutive or not.
However, the most
frequent type of intermittent fasting is the one that follows the 16/8 pattern.
In this case, 16 hours a day should be spent fasting, taking advantage of the
hours of sleep. During the remaining 8 hours of the day is when the relevant
intakes are allowed.
A diet of intermittent
fasting would not be especially different at the nutritional level of a
balanced diet, except that we must take into account the practice of fasting.
Is Intermittent
Fasting Good?
It is certainly a
controversial issue. More and more studies are coming out that support
therapeutic fasting as a possibility in the prevention and treatment of some
diseases. It seems that, indeed, practicing autophagy has positive effects on
health, as it would be a kind of detox effect.
However, I think that
the answer to whether intermittent fasting is good, should go a little further.
Fasting to
Lose 20 Kilos?
A patient who recently
came to me for consultation told me that her plan was to follow the
intermittent fasting diet until she lost 20 kilos and then return to normal.
Thank goodness that, as a precaution, she had thought it a good idea to talk to
a professional about this beforehand.
See, this is what I'm
talking about. I imagine that if you've read the article carefully, you'll know
why this is a lousy idea.
An Expert
Nutritionist's Opinion on Intermittent Fasting
I suppose that like any
change we have to study it, open our minds and begin to contemplate it as a
therapeutic option.
As of today, I would
not recommend it. The reason for this is that it seems to me that it can easily
undermine mental health. I believe that following an intermittent fasting diet
can be a rational excuse to cover up an eating disorder, and I am not saying
that all people who practice intermittent fasting suffer from an eating
disorder, far from it.
Furthermore, I believe that intermittent diets are being marketed as magic diets to lose weight fast. And if you look a little bit, in the end it's all about not eating or eating less. I think it is possible to lose weight by eating, with flexibility and patience.