Homeostasis in the Body
Healthy Homeostasis
Your body tells you what it "needs." You know when you need to eat, or drink, and you have cravings for foods that supply the nutriments that you need.
Several studies have shown, that young children given a wide variety of foodstuffs to eat from, and freedom of choice, choose a diet that's surprisingly good, in terms of nutritional needs.
Homeostasis controls your body temperature, your weight, your blood sugars, the amount of cholesterol in your system, when you feel sleepy, your desire to exercise; - almost everything you do, is affected.
When your homeostatic system is itself "healthy" it will help you to be healthy too. But because of our personal behaviours, or because of social behaviours we adopt, we can force our homeostatic system to find another "set point" that is not so healthy.
Control of Body Cells
All the cells in your body are under control. That control is from the signalling of other surrounding cells. Every cell requires "You're OK" signals from surrounding cells to continue to "live."
In the absence of "You're OK" signals; cells are programmed to switch themselves off. This process is called apoptosis. It's a process active in your body everyday.
Homeostasis is another example of this sort of control, with the signalling system being hormones and enzymes, linked into the nervous system as well. It's a whole body system; it can't be understood by looking at disassembled parts.
Your Body Adapts to Your Behaviour or Circumstances
Your body tries to find a way to cope with your behaviours, and makes the best adaptation between that behaviour, and the needs of your body.
We know that the body adapts to excessive alcohol use, drug abuse, over-eating, obsessive exercise, and to chronic pain.
The body also adapts to traumatic experiences, like child abuse, or repeated violence or warfare.
Prisoners kept in isolation, slaves, many women in abusive relationships, develop a delusional self-protective mental state, that makes them feel safe, yet reinforces their entrapment. That too becomes part of adaptive homeostasis.
We can call the new set point, that the body achieves, adaptive homeostasis. A place that "feels right," that allows you to continue with your life. This becomes how you normally are.
These forms of adaptive homeostasis are not healthy; they are just a way of coping. The long term effect of this sort of adaptation is likely to develop into a recognised physical or mental illness.
Dietary Homeostasis
Most of the time in our modern world people eat sweet foods or carbohydrates every 2-3 hours. This overloads the blood with glucose, creating a dangerous circumstance. The pancreas creates the hormone insulin, helping the body to use glucose as a primary fuel, and to store any excess glucose.
For most people this glucose based metabolism works well. However, you can force it out of balance.
The body learns to adapt to a constant excessive level of glucose, eventually becoming carbohydrate intolerant (alternatively named insulin resistant).
Throughout history, food supply has been erratic, seasonal, sometimes feast and sometimes famine. You see that now, in less developed countries or during war, when food supply is not reliable, people may be eating only one meal a day. Starvation introduces another form of metabolism, using ketones derived from body fat, and protein, or nutritional fat and nutritional protein.
The human body adapts perfectly well to metabolising ketones. Once you become ketone adapted your body will try to keep you in that homeostatic state. For instance if you do stimulate an insulin spike in your diet, insulin will be used to keep you in nutritional ketosis, rather than to switch back to glucose metabolism.