No Cerveza... No Trabajo
Join Date: Jun 2002
Location: Where's my beer?
Let expand what I wrote a little...
You have a basal metabolic rate. This is the number of calories you require everyday to breathe, keep the heart pumping, etc.
When your body can obtain all the basal calories it requires throughout the day via food intake, the body can efficiently burn the fat stores. When food intake is reduced below this level, it has an unwanted effect on where your body gets its energy from.
Your body's first choice for energy is also glycogen (blood sugar). After its gone, your body still requires glycogen to run its nervous system (ever not eat and get light headed? you've run out of glycogen). If you aren't active, the body will turn to protein (lean mass) to feed the basal metabolic requirements. Most peeps think this is the time when it goes to fat stores for energy. But, the nervous system and brain can only use glucose for energy. Muscles, kidneys, liver, etc can use fat for energy, your nervous system can not.
Your body does not have enzymes to convert stored fat into glycogen. It does have the required enzymes to convert protein into glucose.
So... if the glucose isn't available, it will turn to your lean mass to convert it into glucose (which if it didn't you would die).
When all this happens, your body will go into starvation mode, while burning lean tissue, which will lower your basal metabolic rate. In doing so, the body will also start storing as much as it can as fat, as a safety precaution.
So, if you want to keep your weight, you need to eat as many calories as you are expending (basal + voluntary calories).
If you want to lose weight, you have to eat less calories, but at least the number required for basal metabolism to occur (if you don't you will start burning lean tissue as opposed to fat).
If you want to gain weight, you have to eat more calories than your expend (basal + voluntary calories).
Last edited by 01WhiteCobra; 05-01-2003 at 02:47 PM.