In 2022, the number of overweight children under the age of 5 was estimated at 37 million people. Although it was formerly thought to be an issue in wealthy nations, overweight people are becoming more common in low- and middle-income nations as well. Notably, obesity in children and adolescents has significant psychosocial effects; it impairs quality of life and academic performance and is exacerbated by discrimination, unfavorable attitudes, and bullying from others. To study the morphometric parameters of mesenteric, epididymal, retroperitoneal and the white adipose tissue under the skin in rats fed a high-fat diet. In rats on a standard diet, the specific gravity and average size of adipocytes of epididymal adipose tissue predominate. A high-fat diet causes all forms of adipose tissue, with a predominance of subcutaneous, to have a higher specific weight. An increase in the specific mass of visceral fat depots is associated with the predominance of large adipocytes. In subcutaneous adipose tissue in rats with a high-fat diet, small adipocytes predominate in comparison with adipose tissue of other localization.