Premise
Losing weight is a process physiological characterized by the reduction of the reserve adipose tissue, to which is added, as a consequence, a decrease in the total body mass.
The slimming process is based on four main factors, which, depending on the case, can prevail one over the other:
- lack of balance between energy introduced with food (lower) and energy consumed by cells (upper) → typical of low-calorie diets;
- increased metabolic impact of foods → typical of high-protein / ketogenic diets and / or rich in nerve foods;
- increased metabolism → typical of slimming regimes that provide for the association of moderately low-calorie diets with toning and muscle strengthening activities; temporarily also favored by the use of nerve / thermogenic foods or supplements;
- achievement of the nutritional balance that affects both the nutrients and the nutritional components (first of all, the fiber) → typical of balanced, moderately low-calorie slimming regimes, which provide for a weight loss in the order of 500/750 grams per week.
In general, weight loss exploits a complex mechanism of positive and negative feedbacks that affect the entire metabolism, the hormonal axis and the various cellular processes of the tissues. More precisely, to lose weight it is necessary to place the body in conditions of "catabolism", that is, of "demolition" of the reserve tissues for energy purposes (the "opposite" of "anabolism" or "construction").
The main targets of the catabolic slimming process are subcutaneous fat, visceral fat, muscle glycogen and hepatic glycogen; however, for various reasons, an excessively intense or prolonged catabolic phase can also significantly compromise the integrity of other structures, primarily the muscle.
Note: weight loss is not a selective process on fat mass, therefore a mild catabolism of other tissues is almost always inevitable; this can be limited by starting a well-thought-out muscle-building protocol or, less intelligently, by using doping (thyroid hormones, steroids, somatotropin, etc.). On the other hand, this depletion can be both imperceptible and very intense, depending on the "speed" of weight reduction, nutritional balance, volume and type of motor activity, etc.
