PL
Odpowiedź układu hormonalnego na żywienie ma charakter adaptacyjny, służy dopasowaniu metabolizmu do ilości i rodzaju dostarczanych substratów energetycznych i budulcowych, a więc zapewnieniu homeostazy. Modulacje funkcjonowania układu hormonalnego przez pokarm mogą mieć istotny wpływ na skuteczność postępowania terapeutycznego. W dietoterapii nadwagi i otyłości szczególne znaczenie ma odpowiedź hormonalna wpływająca na regulację bilansu energii organizmu, decydująca o pobieraniu pokarmu i wielkości wydatku energetycznego. Do hormonów pełniących takie funkcje regulacyjne należą między innymi lepty na, hormony tarczycy i insulina.
EN
Leptin, the long-sought satiety factor of adipocytes origin, has emerged as one of the major signals that relay the status of fat stores to the hypothalamus and plays a significant role in energy homeostasis. Compare to healthy controls, some obese individuals have higher absolute values of leptin, indicating leptin resistance. Limitation of food intake leads to a fall in serum leptin level as well as suppression of its activity. This in turn can increase appetite and reduce energy expenditure, which can translate the problems encountered in body mass reduction programmes. Restricted feeding results in significant alterations in thyroid hormone economy characterized by decreased circulating levels of thyroxine (T4) and triiodothyronine (T3) and leads to reduction of metabolic rate. Diminished thyroid function during starvation may at least in part be caused by a reduced hypothalamic TRH release as the result of lowering of TSH secretion. Weight loss decreases regional depots of adipose tissue and improves insulin sensitivity. Interventional weight loss data underscore the potential importance of visceral adiposity in relation to insulin resistance and suggest that above a certain threshold of weight loss, improvement in insulin sensitivity does not bear a linear relationship to the magnitude of weight loss. Reduction in energy intake below needs elicits hormonal changes with concomitant adaptations leading to diminution of energy expenditure and consequently to a decrease in body fat mass. Among others, restrictions are directed to hypothalamic-pituitary-thyroid axis, leptin and insulin secretion and activity. Energy restriction by affecting several mechanisms of hormone secretion and activity could change hormonal status also by alterations in the relationships between hormones.