Basic information that you probably already know, but good to reinforce.
Homeostasis is the body's feedback mechanism for regulating, restoring, and maintaining a genetically determined balance. When homeostasis is disturbed, ill health results.
The amount and distribution of body fat is genetically determined, as are other physical characteristics such as hair color and texture, eye color, facial shape, and body proportions.
Body weight remains relatively constant over long periods of time.
Set-point refers to a genetically determined amount of body fat that the body actively defends. This is the only weight at which the body is normometabolic.
Each individual will naturally maintain a weight within a predetermined range.
The body acts in a way as to maintain this weight range and will defend it vigorously by altering metabolic rate and intesity of hunger if it is challened.
Once people stop actively controlling food intake, their weight automatically returns to the body's preferred weight.
Long term exposure to a high-fat diet of more palatable foods (above approximately 40% calores from fat) results in a shift upward in set-point.
Folling a regular exercise program shifts the set-point to a lower body weight. Regardlesss of the amount of exercise this lowering will not be more than approximately 5% of the set-point weight.
A person can choose to maintain a body weight that is below her set-points weight range, but only with progressively greater disruption to her life due to the increased amount of time spent thinking about food, weight, or hunger as her body attempts to return to homeostasis.
Homeostasis regulatory devices are autonomic and thus happen automatically, we have no conscious control over them.
Our bodies can communicate to us, but we cannot communicate to it.
Our bodies communicate physical needs such as need for sleep, need for water, and need for food.
We cannot communicate to the body's regulatory mechanisms that control fat storage that we have decided to maintain a weight below our set-point. Our bodies thus assume that we are straving due to an uncontrollable lack of food (such as faime). It thus responds the way it has evolved to respond. It reacts by increasing sensations of hunger or thought about food, weight or hunger.
...i guess this reinforces something I heard - that eating disorders are the only "diet" that really works, because we can defy homeostasis. sad, but true.