Role of “Set Point” in Body Size
From our day of birth do we have regulatory systems already in place for personal level of fatness or thinness? Other body systems must operate within a narrow range such as blood pressure, blood sugar, blood chemistry levels, and body temperature. If these levels become too low or too high, our body becomes ill and long term damage can occur. Set point is the term used for this narrow range of usual or natural levels that the body regulates and defends to keep it there. The development of your adult body weight--with all its genetic, environmental, cultural, and personal behaviors effects on it--is assessed by each person’s body and the “set point” becomes established. When a person has an energy deficit either by dieting or illness, the body turns up the appetite mechanism in order to return to usual levels. Thus a person’s adult weight is pretty constant. The “set point” can also endure through eating excesses for a short period of time, but can be over-ridden by consistent over-eating. The new level of fatness becomes the “set point” that is easily maintained.
To change this “set point” to maintain weight loss, the level of effort required is significant with consistent changes in eating behaviors and activity level. One study showed that in successful weight loss maintenance, women ate only about 1300 calories per day and the men about 1700 calories with very low levels of fat intake (about twenty-four percent). They also exercised almost daily. In fact, some researchers recommend actually increasing your daily exercise from thirty minutes per day to sixty minutes per day once you move from dieting to weight maintenance. You cannot return to old eating behaviors and activity levels to keep this lower “set point.”