I've had this question for a long time, I can't seem to make sense of it. Since we store fat on our bodies for an added, or emergency fuel source, why on earth would the body choose to burn muscle when there is a fat source available? That is the purpose of fat! I can see the body burning muscle for survival after all the fat has been depleted, kinda like burning the furniture to stay warm, but why would you burn the furniture when there is firewood? I know it happens, I just don't understand it. Hmmmmm

Geo - I just read an article in this months' MM that says that when your body goes into starvation mode (due to too low a calorie intake), our BMR slows down. Then, "our bodies begin metabolizing our own muscle tissue, converting it into glucose for its primary energy source in order to perserve fat stores that are essential for survival." And, "the activity of our fat-storing enzymes increases and our fat-burning enzymes decrease, so we become very efficient at storing fat".

Sorry - it doesn't really say "why" that is, just that that's what will happen if we eat too few calories - less than 1200 for women or 1800 for men. Sounds like our bodies consider the muscle more expendable than the fat!
Cindy

ok I can answer this one.....

the reason is that fat is dormant and isn't calorie expensive to keep so it sits there and is used last. Muscle on the other hand is expensive and takes calories to maintain (that is why the more muscle you have the more calories you need to maintain it) - it is active and thus when the body goes into starvation it gets rid of muscle first and fat stores last.

HTH

JC

Ahh ha! JC gave me the answer I've been looking for. I just was reading about this and read that the body uses muscle as fuel first when in starvation mode be cause muscle is a liability. It's calorically expensive to maintain. Just like JC told me back in February. I'm slow but it finally all makes sense to me.