Effectiveness of the Use of External Body Weight in the Regulation of Body Weight, Body Composition and Analytical Parameters in Adults With Grade II and III Obesity

BACKGROUND Obesity is one of the most prevalent and booming health and social problems in recent decades in industrialized societies. Obesity rates in European countries such as the United Kingdom, Germany, France and Spain fluctuate between 23 and 29% in the adult population, according to the World Health Organization (WHO). These values increase to 42.4%, 27% and 31% in the United States, Canada and Australia, respectively, considering data from the last 5 years from the main health agencies of these countries, making it a social and public health problem.

The etiopathogenesis of this condition is multifactorial; the obesogenic characteristics of the environment can influence gene expression conditioning the development of obesity. Increased caloric intake, influenced by high-fat diets (Westerns' diet), the absence or insufficiency of physical activity and alterations in energy metabolism seem to be the three fundamental factors contributing to the development of obesity. Moreover, these factors seem to play a major role in the development of other metabolic entities such as hypertension, dyslipidemia and insulin resistance or type II diabetes, which, together with central obesity, make up the metabolic syndrome. This clinical entity doubles the risk of coronary and cerebrovascular disease, increases the risk of diabetes fivefold, and increases all-cause mortality by 50%. In parallel to the risk factors listed above, some studies highlight the role of a sedentary lifestyle as a factor independent of physical activity in contributing to the development of metabolic pathology. Not only the absence of low, moderate or high intensity physical activity has been correlated with the development of metabolic syndrome, but also the increase in time spent in sedentary activities, with an odds ratio of 2.38.

These intrinsic and extrinsic factors seem to interact and condition each other, altering homeostatic and physiological processes in obese individuals.

Since its discovery and description in the 1990s by Friedman leptin has been the most important hormonal factor in the regulation and control of caloric intake and metabolism, and consequently of body weight and composition. Its peripheral production at the level of white fat tissue and its hypothalamic effects (decrease in orexic neuronal activity and conditioning of dopaminergic reward circuits) condition the individual's response to food, regulating satiety and intake.

Evidence shows that this mechanism is altered in people with obesity where excessive leptin production, due to increased concentrations of fat tissue, and consequently high serum concentrations, condition central and peripheral sensitivity to this hormone, generating, in the long run, lower response efficiency, giving rise to the term "leptin resistance ". This resistance seems to modify the hypothalamic satiety signal, as well as the dopaminergic circuits associated with food intake,predisposing to the appearance or increase of metabolic pathology, especially obesity. This dysregulation in caloric intake appears without alterations in the production and function of ghrelin, a hormone produced in the stomach associated with hunger.