Naked Science Forum

Life Sciences => Physiology & Medicine => Topic started by: Emilio Romero on 26/02/2009 21:44:21

Title: will the body self-consume if needed?
Post by: Emilio Romero on 26/02/2009 21:44:21

I’ve been a runner for over ten years (OK --unofficial poll-- how many runners do we have here? Fess up), and I’ve heard two sides of a story:
That the body will auto-nourish consuming “itself” when there is a sufficient caloric deficit, or that it simply will not, since it’s impossible.
Furthermore, I once found an article that stated “no healthy, well-nourished individual will use its muscular protein to metabolize. The assumption, that a calorie-reduced diet and accompanying endurance training will lead the body to burn its muscular protein, is not true under any circumstances. Muscle cells are only reduced through inactivity. This process is called atrophy”.
The latter sounds as if it makes sense... but where is the truth?
Help please, you’re my last hope.
Thanks
emilio

Title: will the body self-consume if needed?
Post by: Chemistry4me on 27/02/2009 05:03:18

Protein averages about 5% of the total energy expenditure; this can increase to 15% during long periods of intense physical work. Protein usage also increases when glycogen stores are low, in the liver, the protein is converted to glucose, in doing so, helps to maintain blood glucose levels. As glycogen stores are generally lowered when dieting or following a low-carbohydrate diet, it makes sense that more protein will be utilized for energy.

Title: will the body self-consume if needed?
Post by: Chemistry4me on 27/02/2009 05:14:02

Quote

Probably the most important point to remember about cortisol and diet is that when glycogen (stored carbohydrate) in the body gets low, cortisol levels rise. This makes perfect sense when you keep in mind that carbohydrate is your body's preferred source of calories. When the body does not have enough precious carbohydrates available, alternative sources of energy must be found. The only other options the body has for calories are fat and protein. Rising cortisol levels will speed up the breakdown of lean tissue (protein) in your body and convert the released amino acids into glucose (carbohydrate) for fuel. At the same time, rising cortisol will speed up the release of free fatty acids (from your body fat stores), making more body fat available for aerobic metabolism.

http://www.bodybuilding.com/fun/issa79.htm

Title: will the body self-consume if needed?
Post by: Chemistry4me on 27/02/2009 05:22:04

So the truth is: The body will burn its muscular protein if you're on a calorie-reduced diet. Better start eating [:)]

Title: will the body self-consume if needed?
Post by: Don_1 on 27/02/2009 10:35:56

I will do as you suggest C4M

(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fbestsmileys.com%2Feating1%2F7.gif&hash=b651af108de81ddd3124a42bd205a5f7)(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fbestsmileys.com%2Feating1%2F20.gif&hash=63077d6956a2ad5315c7a3d488fdac8c)(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fwww.freesmileys.org%2Fsmileys%2Fsmiley-eatdrink023.gif&hash=7dc4bb6757b36cb58c56233dd252067e) (http://www.freesmileys.org)

Title: will the body self-consume if needed?
Post by: Chemistry4me on 27/02/2009 10:43:29

Watch out for this bloke:

(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fchidiet.com%2Fnews%2Fphotos%2Fgiraffe.jpg&hash=e19d8dec80c913872d72861f5e824cdb)

Title: will the body self-consume if needed?
Post by: Don_1 on 27/02/2009 10:54:25

Stone me! A Michelin Giraffe!

Title: will the body self-consume if needed?
Post by: Chemistry4me on 27/02/2009 10:56:43

Quote from: Don_1 on 27/02/2009 10:54:25

A Michelin Giraffe!

A what? [???][???][???]

Title: will the body self-consume if needed?
Post by: Don_1 on 27/02/2009 11:00:04

Michelin (French tyre manufacturer) use the Michelin Man for ads, have you never seen it?
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Ffarm2.static.flickr.com%2F1173%2F774789874_7cee7c85b9_o.jpg&hash=44820026f56db35f807d1ff4d05e3ec6)

Title: will the body self-consume if needed?
Post by: Chemistry4me on 27/02/2009 11:02:33

I have never actaully seen a picture of Michelin but I've certainly heard about it/him/her.

I can certainly see the resemblance to the giraffe.

Title: will the body self-consume if needed?
Post by: dentstudent on 27/02/2009 11:18:21

The STB appears to be very healthy and in action this morning!

Title: will the body self-consume if needed?
Post by: Chemistry4me on 27/02/2009 11:22:19

Don_1 just had to shove his big mouth in.

Title: will the body self-consume if needed?
Post by: Emilio Romero on 27/02/2009 13:31:55

Quote from: Chemistry4me on 27/02/2009 05:22:04

So the truth is: The body will burn its muscular protein if you're on a calorie-reduced diet. Better start eating [:)]

Ok, thanks.
However, which would it consume first, fat or muscle?

Title: will the body self-consume if needed?
Post by: Chemistry4me on 27/02/2009 23:28:14

I am fairly certain that it would be the fats first! Seeing as they produce nearly twice as much energy as the same amount of carbohydrates.