The phenotype of normal weight obesity (NWO) is a serious health risk but is often ignored in the diagnosis of obesity. The WHO defines obesity as an excessive or abnormal accumulation of adipose tissue, but the current diagnosis of adiposity is most often based on BMI values. Some individuals may have an increased amount of adipose tissue even though their BMI indicates that their weight is normal. This negative state is associated with an increased risk of cardiometabolic dysregulation and the subsequent development of chronic non-infectious diseases of the mass type. The global prevalence is only estimated to be around 4.5 - 22 % in the adult population due to the disunited definition of NWO. Current knowledge about the etiology of the disease is not clear. They are most often associated with different dietary habits and lack of physical activity. The recommended treatment and prophylaxis is based on diet and physical intervention at the same time. For early detection of the NWO phenotype, it is recommended to determine the amount of adipose tissue in addition to BMI for the diagnosis of obesity.