Lose Weight: Physiology
The human body is made up of various tissues, including a reserve one called adipose tissue. This, mainly subcutaneous, has the function of storing energy reserves in the form of fats.
The management of the aforementioned stocks takes place thanks to the communication of the adipose tissue with the rest of the organism, 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 manner, while localized weight loss - that is concentrated in specific areas of the body - is very difficult to achieve (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 the adipose tissue but anabolic on the proteosynthesis; it is the insulin-like growth factor (IGF-1) secreted thanks stimulated by 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 districts show a different sensitivity to fat accumulation. The adipose tissue localized 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 few men with flat stomachs and prominent hips-buttocks, but also many men and few women with prominent stomachs and thin hips-buttocks. It is also important to keep in mind that the adipose tissue of subjects with android depot 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 strongly influenced by the state of nutrition in childhood.
This does not mean that, in order to lose weight, it is always necessary to establish the aforementioned catabolic condition. How? By increasing the overall energy expenditure with respect to the caloric intake of the diet, trying above all to emphasize the cellular consumption of fatty acids with respect to creatine phosphate, carbohydrates and branched amino acids.
Belly Weight Loss: When Is It Necessary?
Belly slimming is desirable in various circumstances, which can basically be 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 correlated with metabolic disorders such as: type 2 diabetes mellitus, hypertension and imbalances of lipids in the blood; this morphological feature 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 characteristic that we will also mention in the next paragraph.
- For other secondary reasons; for example, to favor the postural correction of a possible 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 , gastroesophageal reflux with complications and other disorders of the digestive tract, sleep apnea, 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 some third world people, it can affect these elements and cause a very serious pathological decompensation.
Women, before men, suffer the effect of excessive weight loss. Under a certain percentage of body fat (subjective parameter), fertile women accuse a "interruption of the menstrual cycle as a defense reaction of the organism" (the restoration takes place, generally, with the repurchase of 10% more than the weight in which it stopped).
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 trend in the weight referred to the general population in the West tends to increase, 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:
- 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)
- Intravisceral accumulation, typical of sedentary lifestyle, alcoholic abuse and junk food (it is part of the android conformation) does not persist; however, generally, by correcting the diet and motor activity, this type of fat is the fastest to go away
- There is a general predisposition to weight loss or a specific protocol is carried out and that the district is sensitive to catabolism
- 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)
- 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)
- 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 subjects lose weight very quickly compared to those of normal weight; therefore, it is necessary to keep in mind that, most of the time, the belly flat, narrow and sculpted, corresponds to a percentage of fat lower than the average or even the normal threshold. Therefore, it is logical to deduce that the desired aesthetic result will be all the more difficult to obtain, the more significant it is; nevertheless, the more the closer to the goal, the greater the difficulty and the lower the progression of the results.
How to lose weight on the belly?
Let's start immediately the description of the methods specifying that slimming is a general process and regulated only (or almost) by the organism. It is therefore not possible to intervene as effectively as you would like on the localized slimming of the belly, even if some professionals argue the opposite.
Those who claim to have understood the mechanism, on the other hand, suggest a very specific protocol (not uniquely 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 into the following way:
- First of all, the missing energy with respect to weight maintenance (normocaloric), must not exceed 30% of the total daily requirement in normal subjects and 10% in athletes who practice intense activity (personal opinion). Therefore, in the 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.
- 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 intake of mineral salts and vitamins, as well as fibers and other nutritional components (phytosterols, lecithins, polyphenols, etc.)
- Regarding the caloric division 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, that is 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:
- 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.
- The second method is more "modern" and revolutionary, but not always shared; it is frequently associated with alternative nutritional regimes (often characterized by a lack of carbohydrates, rich in proteins and sometimes poor in fats) 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 the 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 movements 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 it 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 most, it is reasonable to think that the degree of vascularization of the adipose tissue may have a "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 the increase in body temperature; its presence in the body is generally very low (except for the Yupik - Eskimo ethnic group).
Well, this is the principle followed by the supporters of localized weight loss: as the 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 capacity of capillaries) is one of the responses to the aerobic training stimulus. However, for fat (as well as for 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 the 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 not) 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 with a greater energy commitment. If so, the same tummy result could be achieved by doing a one-hour walk, rather than 1,000 sit-ups at a time.
To complicate matters, there is the conflicting 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 would like 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 reducing carbohydrates (in the hope of increasing the oxidation of fats) can lead to an excessive increase in catabolism. muscle; 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 in 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 far as the physical activity protocol is concerned, 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 prolonged aerobic activity, obviously respecting 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 does not hurt, but it is always better not to set too many expectations and focus more on diet and sport.
