Set point theory
According to this theory, you have a predetermined weight and level of body fat—called a set point—that your body wants to maintain.
This body fat level is determined by genetics, just like your height.
Exactly how the body controls its fat stores is unknown, but the regulatory mechanism, sometimes called the adipostat, (like a thermostat for fat) is located in the brain. The adipostat monitors the body’s fat stores, possibly through the actions of the hormone leptin, and works to maintain the set point by adjusting appetite, physical activity, and resting metabolic rate to conserve or expend energy. Thus, eating and physical activity may be subtly controlled by the set point mechanism.
