Mechanisms involved in fat metabolism slowdown??

[Ralph_Wiggum]

Ok, I am not new to dieting by any means, but, I am at the point where I want some concrete information about why I diet the way I do. I specifically want to know about why the body starts to slow down metabolism and fat burning as your diet progresses.

I have heard all the lines such as "your metabolism slows down to adjust to your diet", "you have to trick your body", "to burn fat and keep muscle, you have to diet slow and smart", etc etc...but I am wondering how much myth is thrown into those statements which I generally believe.

1. What causes the thyroid to slowdown output?

2. What causes Leptin levels to drop so fast?

3. What causes the body to favor muscle mass instead of fat for fuel, when fat is stored specifically for energy purposes?! Why is everyone so paranoid that the body will rush to eat up all its muscle mass @ the slightest drop in calories?

4. How fast do all of these changes listed above happen?

5. How long does it take to get the body back into optimal fat burning mode after dropping your calories to an intake level enough to burn around 1-1.5 pounds per week?

I've pretty much heard all of the pseudo-scientific explanations to the above questions, but I'd like to hear more concrete explanations that can be backed up with relevant data (relevant studies and science in reguards to body composition changes).


Part of this info I get I will use in my competition I am having w/ a good friend of mine where the person b/w the 2 of us who loses the most bodyfat in 6 weeks wins money. We talk/argue about this stuff so much and I just suggested we both put up or shut the fuck up...I want to be a fat burning maniac, so I want to tweak my methods to do so.

 

[The Red Dragon]

use pubmed for that kind of information, clinical peer reviewed journal articles (science does lag behind bodybuilder knowledge, but there's lot of bogus shit in bodybuilding whether its from self-proclaimed scientists or marketers)

I've read some pretty bogus stuff out there. I think I read something about muscle glycogen being released into the blood during cardio and therefore, it makes AM cardio useless lol.

I no longer try not to focus on the science of bodybuilding, there's like 10 000 variables you have to control for. Just eat and train properly, do it from empirical knowledge than theoretical knowledge...Theory gets ya no where in this game really, it did nothing for me (I'm natural btw, if I started shooting T3 or Insulin and shit then I can see it being useful)

 

[Ralph_Wiggum]

so I guess it is journal searching for me if I want more concrete info... I was hoping some members here who have competed before could provide info, but I understand how my post was packed with questions, and given a person's busy life, it is a quite time-consuming response. No big deal, I'm not crying about it.

I'll frekin crush this guy in our contest anyway . Instinct vs "by the books". I'm the instinctive person, and he feels that college professors, bodybuilding magazines, and doctors need to tell him what to do instead of working with his own body. I'm going to suggest bumping up the timeframe of this contest to 9+ weeks total so we can both get in better condition.

 

[Makavelli]

1. What causes the thyroid to slowdown output?
The thryroid is slowed down due to less conversion of T4 to T3. This is caused by the body recognizing that it's losing too much fat too fast. It's a survival mechanism whereas the body tries to conserve bodyfat to be used for fuel later. When this happens a plethora of bad things go along with it. The body begins to use muscle for fuel in an attempt to conserve fat. So basically you get smaller and fatter...

2. What causes Leptin levels to drop so fast?

Again, the survival mechanism.

3. What causes the body to favor muscle mass instead of fat for fuel, when fat is stored specifically for energy purposes?! Why is everyone so paranoid that the body will rush to eat up all its muscle mass @ the slightest drop in calories?
Dropping cals slightly and adding cardio to expend additional calories is the best way to burn off fat. This way the body thinks that it's being fed properly. No panic. No muscle loss.

4. How fast do all of these changes listed above happen? After about 2 weeks.

5. How long does it take to get the body back into optimal fat burning mode after dropping your calories to an intake level enough to burn around 1-1.5 pounds per week? 1-2 weeks of maintenance eating.

 

[Ralph_Wiggum]

So the thyroid output and leptin levels start dropping after 1-2 weeks of a 500 calorie/day deficit below your total caloric expendature per day (1 pound of fat per week)? That is faster than I thought. Do you have any cites for that info?

for the competition I am having w/ my friend (which I want bumped up to a 8-9 week timeframe), I plan on cutting calories gradually. 3000/day, 2600/day, 2200/day, then finally 1800/day untill a 1 week refeed of 3500/day. Each caloric phase will be for 1-2 weeks since this thing is 8-9 weeks long.