The protective effect of obesity on bone tissue has not been unequivocally demonstrated. On one hand, it is known that obese people have a lower risk of osteoporotic fractures compared with normal-weight individuals. On the other hand, obese patients are characterized by disorders of calcium-phosphate homeostasis and bone metabolism. Moreover, it is not known whether it is fat or lean body mass that determines the development of bone mass. It can be assumed that adipose tissue exerts independent effects on bone remodeling by releasing a number of biologically active substances. Moreover, it seems that the main mechanism of action of these substances is closely related to the type and location of adipose tissue in the body. The present article describes the relationship between fat and bones, including the effect of body weight on bone tissue, the local mechanisms of osteoblast and adipocyte differentiation, and the hormonal activity of adipose tissue.