Leptin is a peptide hormone secreted by fat cells. Leptin regulates energy metabolism and fat burning in the body; it takes part in the regulation of body weight, causing a decrease in appetite and reducing food intake. Leptin content in the blood increases with increasing obesity and decreases with decreasing adipose tissue. High leptin levels may indicate an increased risk of cardiovascular and thrombotic complications.  Preparation It is recommended to give blood in the morning on an empty stomach (you can drink water) in the morning hours - from 8 to 11 hours. Avoid food overload, alcohol intake 1-2 days before the study.  When fasting may decrease the indicators.