It is important to remember that as your body breaks down fat, the number of fat cells remains the same but each fat cell becomes smaller in size or when we burn fat, the amount of fat stored within each fat cell decreases and the fat cell simply shrinks in volume.The fat gets break down into the fatty acids and glycerol.The fatty acids are utilized by the body for the production of ATP while glycerol enters into the Krebs cycle.With the correct diet and exercise regime developed or prescribed according to the individual's body type, fat cells can be shrunk enough to reduce your weight or make you lean.However, our genes control the number of fat cells in the body,but our lifestyle and the eating habits play a main role in the weight management.