By Dr. Roberto Uliano
The common cause of obesity is an increase in caloric revenue compared to exits and consequently in an inadequate energy expenditure compared to what you eat. The common therapy for overweight and obesity is to restrict the caloric intake through a more or less restrictive diet. This is the most immediate method for balancing the energy balance, but it has the side effect of reducing the lean mass and some components of the metabolism, which will later be investigated further. Furthermore, diets have the limit of the patient's adherence to therapy both from a psychological and a physical point of view, and in some cases induce the distortion of eating and living habits. An important aspect that is still little considered by patients today is to increase energy expenditure by influencing everything concerning the metabolism. In this article we will deepen our knowledge of metabolism in all its aspects and how it can be increased.
Metabolism in its classical definition corresponds to the energy expenditure of the organism for all its vital functions. The cells, tissues, organs (liver, muscle, brain, heart, etc.) carry out their activities through energy forfeited with food. Metabolism consists mainly of four components:
- BASAL METABOLISM;
- THERMOGENETIC ACTION OF FOOD (TID);
- ADAPTIVE THERMOGENESIS;
- ENERGETIC EXPENDITURE FOR ACTIVITIES.
Basal metabolism
The basal metabolism represents the minimum energy expenditure for the survival of the organism. It constitutes 65-75% of total metabolism. Although the basal metabolism is due to the essential activities of the organs (snc, liver, heart and other organs) its variations among individuals depend above all on the musculature, the body surface and the lean mass (the lean mass is all that is not adipose tissue ). Women have a lower basal metabolic rate than men (5-10% less) due to a lower amount of lean mass and a greater quantity of adipose tissue. The basal metabolic rate decreases by about 2-3% every decade of life in both men and women, as the lean mass is replaced by adipose tissue, which by its nature has a lower energy metabolism. Regular exercise, both of strengthening and of resistance is able to increase the basal metabolism by 8% and to counteract its decrease with advancing age. During exercise, muscle metabolism can increase up to 120 times.
The main factors influencing basal metabolism are listed below.
Thyroid hormones (thyroxine and triiodothyronine) in maximal quantities (thyrotoxicosis) increase the metabolism even by 50% -100%, while their deficit (hypothyroidism) reduces it enormously. This is because thyroid hormones induce an increase in the speed of chemical reactions in many cells of the body. Functional adaptation to the climate (greater secretions of these hormones when it is cold or less in hot weather) contributes to the differences in basal metabolism that are found in people living in different geographical regions; for example, people living in Arctic countries have a basal metabolism of 10-20% greater than the inhabitants of tropical regions. These physiological bases go against the trend compared to the various beauty centers that advertise weight loss through rooms above the normal temperature. At most, these machines can cause water loss and therefore lead to dehydration. Rather than resorting to these useless strategies, machinery with slightly low temperatures should be invented. With the cold, therefore, at least if there is not a poor thyroid function, it is possible to lose weight more easily, with the precaution of not eating more (it is known that with the cold it increases hunger, precisely because it increases the metabolism). Consider that to increase the basal metabolism by 30% you should administer three times the amount of thyroid hormones compared to the physiological ones. Which means huge side effects, which many people who are losing weight with the help of thyroid extracts (TRIAC) know well.
The male sex hormone, testosterone, can increase basal metabolism by 10-15%. Much of the effect of testosterone on metabolism is due to its anabolic action, which increases skeletal muscle. This is noticeable in adolescents who lose weight easily during development. Many individuals who have testosterone deficiency can increase it through a strengthening sport. Women with excessive amounts of testosterone (characteristics of hirsutism and polycystic ovary) store visceral fat inside the belly and can undergo states of insulin resistance and therefore an altered metabolism of sugars.
Growth hormone (GH) can increase metabolism by 15-20%. Children in full growth have a higher metabolism.
An important note is to be made about hormones (testosterone, nandrolone, GH) that are administered in various gyms to increase metabolism and muscle mass. Although the results may be those desired, there are not few side effects and the chances of incurring serious illnesses.
From what was said in a weight loss program it is important to associate a constant physical activity with a low-calorie diet. In fact physical activity, in addition to increasing muscle mass, induces an increase in testosterone in men and stimulates the production of hormones (catecholamines) which, as we will see, are able to increase the efficiency of thermogenesis, another important component of metabolism.
Measurement of basal metabolism .
The actual measurement can be accurately performed through indirect calorimetry, a fast and non-invasive reference method. It consists in measuring the consumption of oxygen and carbon dioxide inspired and exhaled by the subject in a precise interval of time. Based on the recorded data, the basal energy metabolism is then deducted. The actual measurement of metabolism lays the foundation for a correct nutritional program. In fact, giving a diet far below one's metabolism induces a loss of lean mass with a consequent decrease in the metabolism itself. Under these conditions it is more likely that weight loss will stop very soon. In fact, weight loss should not be greater than one kilo per week, corresponding to around 1000 kcal less than the total daily energy expenditure.
Thermogenesis and metabolism ยป
