Lose Weight: Physiology
The management of the aforementioned stocks takes place
thanks to the communication of the adipose tissue with the rest of the body, by
means of the circulatory stream (transport of lipids, hormones and
neurotransmitters).
Weight loss consists in the emptying, but not of death, of
the cells that structure the adipose tissue; Losing weight therefore means
reducing the amount of fat stored in the cells of the adipose tissue.
Weight loss is a physiological process that affects the
reduction of subcutaneous and / or visceral fat mass. It occurs when the
organism tends to be subjected to a catabolic stimulus, that is of
"demolition". This stimulus can be more or less specific, depending
on the hormones that regulate it, the sensitivity of the tissues, the state of
nutrition, sex, age, etc .; generally, however, if not opposed by other
specific mediators (typical of physical exercise, such as somatotropic
hormone), catabolism tends to affect the whole organism; it means that when you
lose weight you tend to do it in an almost generalized way, while localized
weight loss - that is, concentrated in specific areas of the body - is very
difficult to obtain (see below).
The catabolic hormones par excellence are: glucagon and
adrenaline; on the contrary, the anabolic one par excellence is insulin. There
is also a quantitatively less important anabolic mediator, which exerts a
catabolic effect on adipose tissue but anabolic effect on proteosynthesis; it
is the insulin-like growth factor (IGF-1) secreted thanks to the stimulation of
the famous somatotropin. Other important mediators are testosterone and thyroid
hormones.
The tissues, some parts more than others, show a rather
different chemical-regulatory sensitivity to catabolic and anabolic stimuli.
For example, muscle tissue tends to degrade extremely slowly compared to
adipose tissue; this depends on the fact that the organism tries to hinder
muscle catabolism while promoting the elimination of fat (respecting the
specific biological functions).
Similarly, certain areas show a different sensitivity to fat
accumulation. The adipose tissue located in the abdomen (android distribution,
typical of men) is affected earlier by catabolism than that on the hips and
buttocks (gynoid distribution, typical of women). Furthermore, those with an
apple-shaped conformation (the first) lose weight more easily than those with a
pear-shaped conformation (the second). There are many women and a few men with
flat stomachs and prominent hips-buttocks, but also many men and few women with
prominent stomachs and slim hips-buttocks. It is also important to keep in mind
that the adipose tissue of subjects with android deposit is predisposed to
adipocyte hypertrophy (due to the secretion of the hormone cortisol, more
frequent in humans); on the contrary, that of subjects with gynoid deposits is
more oriented towards hypertrophy and hyperplasia (increase in volume and
number, due to the presence of estrogens, more frequent in women). These
characteristics are greatly influenced by the state of nutrition in childhood.
The fact remains that, in order to lose weight, it is always
necessary to establish the aforementioned catabolic condition. How? By
increasing the overall energy expenditure compared to the calorie intake of the
diet, trying above all to emphasize the cellular consumption of fatty acids
compared to creatine phosphate, carbohydrates and branched chain amino acids.
Belly Weight Loss: When Is It Necessary?
Belly slimming is desirable in various circumstances, which
can be basically divided into 3 points:
• In conjunction with an increased cardiovascular risk; in
fact, the increase in abdominal circumference is associated with an increase in
the risk of atherosclerotic formations. This condition is typical of obesity,
therefore it is related to metabolic disorders such as: type 2 diabetes
mellitus, hypertension and imbalances of lipids in the blood; this
morphological characteristic is also one of the diagnostic criteria of the
metabolic syndrome. It is more serious when the accumulation of fat is visceral
(inside the peritoneum and not outside the abdominal muscles), a feature that
we will also mention in the next paragraph.
• For other secondary reasons; for example, to favor the
postural correction of any hyperlordosis that negatively affects the lifestyle.
In the male, being related to general obesity, belly fat is also responsible
for many other joint discomforts, sleep impairments, fatty liver disease,
gastroesophageal reflux with complications and other disorders of the digestive
tract, sleep apnea ne, changes in cardiac activity, etc.
• For aesthetic purposes.
Remember that body fat is not all concentrated in adipose
tissue and a minor part of the total is defined as primary or essential. Equal
to 3-5% in men and 8-12% in women, essential fat is crucial for the correct
functioning of the human machine and for its survival. It is included in: cell
membranes, bone marrow, nervous tissue (myelin sheaths), organs (kidneys,
liver, heart, lungs, etc.) and breasts (in women). Excessive weight loss, such
as that which can be observed in patients with anorexia nervosa or in certain
third world people, can affect these elements and cause a very serious
pathological decompensation.
Women, before men, suffer the effect of excessive weight
loss. Below a certain percentage of body fat (subjective parameter), fertile
women experience an interruption of the menstrual cycle as a defense reaction
of the organism (recovery generally occurs with the regaining of 10% more than
the weight in which is interrupted).
We conclude this paragraph by recalling that the percentages
of body fat (subcutaneous, that measured with the BIA and plicometry)
considered normal are: 12-15% for men and 25-28% for women.
The Belly: A Difficult Zone
The belly or abdomen is an area of great interest for all
lovers of aesthetic culture. The average person (male and female) would like to
have it flat, sculpted and with a slim waistline. On the other hand, the weight
trend referred to the general population in the West tends to grow, often
beyond the normal weight threshold. Ultimately, even if it is a district more
prone to weight loss than others, to achieve the desired result it would be
desirable that:
1. There is no hyperlordosis condition; otherwise, even in
conditions of maximum weight loss, the abdomen will always be prominent (factor
independent of the adipose tissue)
2. Intravisceral accumulation, typical of sedentary
lifestyle, alcoholic abuse and junk food does not persist (it is part of the
android conformation); however, in general, by correcting nutrition and motor
activity, this type of fat is the fastest to go away
3. There is a general predisposition for weight loss or a
specific protocol is carried out and that the district is sensitive to
catabolism
4. There is a balance in the exchange of fluids between the
circulation and the interstices; translated, that there is no subcutaneous
water stagnation (typical of sedentary people and anyone with a precarious
blood circulation)
5. There is a predisposition of the track to be narrow and
not wide; in this case, in the training protocol it would be better to avoid
exercises that hypertrophy the external and internal oblique muscles too much,
and the transverse muscles (factor independent of the adipose tissue)
6. The body does not slow down the weight loss too much by
reducing the fat mass.
Regarding the last point, there is also an inverse
correlation between the extent of weight loss and the ease with which it
occurs. Very fat individuals lose weight very quickly compared to those of
normal weight; It is therefore necessary to keep in mind that, most of the
time, a flat, narrow and sculpted stomach corresponds to a percentage of fat
below the average or even the normal threshold. Therefore, it is logical to
deduce that the desired aesthetic result will be the more difficult to obtain,
the more significant it is; nevertheless, the closer one gets to the goal, the
greater the difficulty becomes and the lower the progression of the results.
How to lose weight on the belly?
We immediately begin the description of the methods by
specifying that weight loss is a general process and regulated only (or almost)
by the body. It is therefore not possible to intervene as effectively as you
would like on the localized weight loss of the belly, even if some
professionals claim the opposite.
The truth is that, if there is a correlation between fat
distribution and sex, hormones, genetics, age, alcohol and food abuse, physical
activity level, etc., it has not yet been revealed with which system. (if it
exists) it is possible to reduce mainly the fat of a certain body segment.
Those who claim to have understood the mechanism, on the
other hand, suggest a very specific protocol (not univocally accepted) that we
will illustrate in the next paragraph.
For now, let's try to understand how to reduce the
percentage of excess fat in our body in a generalized way.
• Balance the diet. The diet must be low-calorie, balanced
and well divided. These three criteria translate as follows:
o First of all, the lack of energy with respect to weight
maintenance (normocaloric), must not exceed 30% of the total daily requirement
in normal subjects and 10% in athletes who meadows
cano intense activity (personal opinion). Therefore, in case
the caloric requirement of an individual is 2000Kcal / day, the weight loss
diet should provide no less than 1400Kcal or - if it is a person who practices
intense activity - not less than 1800KCal.
o The nutritional balance provides for a breakdown of energy
macronutrients equal to: about 45-65% of carbohydrates, 25-30% of lipids and
the rest of the remaining energy in proteins; percentages may vary slightly.
Furthermore, the diet must guarantee the supply of mineral salts and vitamins,
as well as fibers and other nutritional components (phytosterols, lecithins,
polyphenols, etc.)
o Regarding the caloric breakdown in the various daily
meals, this varies a lot according to the specific case and to any training
sessions. It is necessary that it includes at least 3 main meals, ie a
breakfast, a lunch and a dinner, approximately in proportions of 15%, 30-40%
and 25-35%; it is also essential to provide 2-3 secondary meals or snacks,
approximately 5-10%.
NB. Some adopt alternative dietary systems to that of the
Mediterranean diet, such as the various high-protein diets (some of which are
ketogenic), the zone diet, the Paleolithic diet, the blood group diet, etc.
Personally I do not agree with them, as they do not always respect the
nutritional balance criteria.
• Plan a specific physical activity protocol for weight
loss; now the complications begin. In fact, to favor the cellular use of the
fatty acids contained in the adipocytes (organized in triglycerides), two
methods can be used, sometimes at the same time:
o The first, the more traditional one, is based on the
direct oxidation of lipids inside the muscle cells. This type of physical
activity must have the following characteristics: long duration (not less than
25-35 ', up to 60-90') and intensity included in the so-called aerobic band,
which tends to be lipolytic, which varies according to subjectivity but is
always below the anaerobic threshold. In practice, the longer you train at
moderate intensities, the more the elimination of lipids (used to meet the
energy demands of training) increases.
o The second method is more "modern" and
revolutionary, but not always shared; it is frequently associated with
alternative nutritional regimes (often characterized by low carbohydrates,
richness in proteins and sometimes low fat) and is based on the concept of
increased oxygen consumption at rest. This parameter, which normally depends on
the basal functions, after a certain type of physical activity increases
proportionally to the intensity and time of exercise. Here the weight loss
protocol uses an indirect system, based on very high intensity sessions, almost
totally anaerobic lactacid and often interspersed, therefore of shorter
duration (High Intensity Training - HIT or High Intensity Interval Training -
HIIT)
NB. It is possible to unify the two systems by exploiting an
oscillatory intensity trend, which moves from the lipolytic band to lactic acid
exercise peaks but never maximal, since it is necessary to guarantee the
continuity of training (recovery must be active).
Localized Weight Loss: Is It Possible?
As anticipated, some argue that localized weight loss,
including that of the belly, is not impossible to achieve.
Taking a very short step back, at point 4 of the paragraph
entitled “The Belly: A Difficult Zone”, we talk about the correct exchange of
fluids. This concerns the displacements from the circulation to the interstices
and vice versa, and mainly depends on the concentrations and the degree of
vascularization.
With regard to the concentrations, that of the blood is more
or less constant (oncotic and osmotic regulation); if this were not the case,
some very serious health imbalances would appear. On the contrary, there is the
possibility that the interstitial fluids are enriched with ordinary or
basically obsolete molecules (some call them "toxins"), which in turn
exert an osmotic effect, aggravating water retention; a very indicative example
of this principle is also part of the formation of cellulite.
Personally, I believe that this is NOT a very frequent or
proportionally so important condition, especially in subjects who practice
regular physical activity (who are less predisposed). At the most, it is
reasonable to think that the degree of vascularization of the adipose tissue
can be of primary importance in all its interactions with the organism.
NB. The most vascularized portion of subcutaneous body fat
is probably that of brown fat, that is the substrate dedicated to increasing
body temperature; its presence in the body is generally very low (except for
the Yupik - Eskimo ethnic group).
Well, this is the principle ridden by supporters of
localized weight loss: as vascularization increases, the ability to capture
chemical signals (hormones and neurotransmitters) should also increase, but
above all the release of fats towards the bloodstream.
Now, the fundamental question is: how could vascularity be increased?
If adipose tissue had the same properties as striated muscle
tissue, the goal would not be difficult to achieve, since the increase in
vascularization (number and flow of capillaries) is one of the responses to the
aerobic training stimulus. However, for the fat (as well as for the
integuments) this system cannot be applied.
To date, various physical methods have been proposed such
as: localized massage (self-massage, vibrating bands, automatic massagers,
etc.), heating (saunas, Turkish baths, synthetic elastic bands, etc.) and,
finally, localized physical exercise. Precisely with regard to the latter, in
the last 40 years researchers have carried out many investigations, some of
which with conflicting results, but most of them are undoubtedly oriented to
disprove this theory.
On the other hand, it is not possible to ignore the opinion
of those who work in the field and of certain high-level bodybuilders;
excluding for a moment nutrition (supplements, notified and otherwise) and
chemistry (doping drugs), various professionals report a noticeable improvement
in results by significantly increasing the volume of training and decreasing
the intensity. It could also be the direct oxidative increase caused by the
increased energy commitment. If so, the same result on the stomach could be
achieved by doing a one-hour walk, rather than 1,000 sit-ups at a time.
To complicate matters, there is the contrasting opinion of
other bodybuilders, also of the highest level, who even DO NOT train the belly
muscles and maintain a "national podium" abdomen.
Conclusions
To conclude, it is important to emphasize that the basis of
the weight loss process is the diet. While exercising, regardless of the
improvement of the state of health, if the diet does not meet the criteria of:
• Negative balance (fewer calories than you consume)
• Nutritional breakdown
no significant variation can occur on the thickness of the
fat folds.
I want to clarify that even the extremeization of the diet
is not a correct behavior. Even with the support of certain food supplements,
organizing the diet by cutting down carbohydrates (in the hope of increasing
fat oxidation) can cause an excessive increase in muscle catabolism; it is
therefore sufficient to take no less than 45% of carbohydrates, with a low
glycemic index and being careful not to exceed the portions (an excessive
glycemic load could excessively stress the increase of insulin).
The same applies to total lipids which, on the other hand, if
too deficient in the diet could induce insufficiency of essential fatty acids
(omega 3 and omega 6), of phospholipids and other secondary components, of
phytosterols and lecithins (not documented in literature) and fat-soluble
vitamins (A, D, E, K).
As regards the physical activity protocol, the mixed one is
undoubtedly the most complete but requires a very careful organization;
therefore, it should be drawn up by a professional. The safest alternative is
always that of moderate and protracted aerobic activity, obviously in
compliance with any pathologies or special conditions.
With regard to localized weight loss, a self-massage or the
performance of some specific exercise are not (normally) harmful to health;
trying doesn't hurt, but it's always better not to set too many expectations
and focus more on diet and sport.
