Rasvakihoon

Rasvakihoon is the biological process by which organisms store excess energy as fat in adipose tissue. In humans, it occurs mainly in white adipose tissue where triglycerides are stored within adipocytes as lipid droplets. This storage form serves as a long-term energy reserve that can be mobilized when energy is needed.

Mechanism and regulation: After a meal or caloric surplus, insulin promotes fat storage by increasing the uptake of fatty acids and promoting lipogenesis. Fatty acids and glycerol are converted into triglycerides through enzymatic steps, and circulating fatty acids from chylomicrons and VLDL are taken up by adipocytes with the help of enzymes such as lipoprotein lipase. Triglycerides are stored in lipid droplets, and adipocytes can increase in size (hypertrophy) and, with prolonged excess energy, in number (hyperplasia). Hormonal signals balance storage and mobilization; catecholamines and other counterregulatory hormones promote lipolysis during fasting or stress to supply energy.

Distribution and health implications: Fat is stored in various depots, primarily subcutaneous and visceral adipose tissue. Subcutaneous fat tends to have a different metabolic impact than visceral fat, which surrounds internal organs and is more closely linked to metabolic risk. Adequate fat storage supports energy homeostasis and protects against energy shortages, but excessive storage—especially visceral fat—associates with insulin resistance, type 2 diabetes, and cardiovascular disease.

Clinical considerations: Abnormal fat storage patterns occur in obesity and lipodystrophy syndromes, where storage capacity or distribution is altered. Understanding rasvakihoon helps explain variations in metabolism, energy balance, and related diseases.