starvation mode: myth or fact?

Mokey41

nice going, now she deactivated. not sure you could have been ruder. hope you have a good day

Considering someone dredged up this thread from over 2 years ago the OP quite likely left a long time ago.

melindasuefritz

Fact

yarwell

When the body is in survival mode, does it always go for the fat first to feed itself?

Fat is the preference for energy storage - we can carry 100,000 calories of fat but nowhere near that amount of anything else. Every night while asleep you use fat from storage to tide you over tot he next morning.

At http://www.cussp.org/sites/default/files/Hall Slides.pdf you can see the science of what happens if you don't eat at all - fasting - where fat oxidation settles down at about 1000 calories a day of energy supply. An overweight woman would have a few months worth on board at that rate.

grimendale

When the body is in survival mode, does it always go for the fat first to feed itself?

Fat is the preference for energy storage - we can carry 100,000 calories of fat but nowhere near that amount of anything else. Every night while asleep you use fat from storage to tide you over tot he next morning.

At http://www.cussp.org/sites/default/files/Hall Slides.pdf you can see the science of what happens if you don't eat at all - fasting - where fat oxidation settles down at about 1000 calories a day of energy supply. An overweight woman would have a few months worth on board at that rate.

Fasting is not the same as starvation mode. When people use intermittent fasting, it is the intermittent part that is the key. Your body will not enter starvation mode in a matter of days, so fasting is not going to do metabolic damage. Maintaining excessive deficits over a long term (weeks or months) will cause a change. Your statement that we carry more fat than anything else is categorically incorrect. We carry far more muscle (assuming you are at a healthy weight). When you carry a very large deficit over a long period of time, your body begins to burn a higher percentage of muscle than fat in order to preserve the energy reserves. Muscle tissue is a less efficient, but more abundant energy source - it has a lot of calories, but is harder to break down. Muscle also requires more calories to maintain than fat does. Thus, when your body encounters a significant, long term food shortage, it burns muscle to ensure the maximum amount of stored energy for the longest period of time. Only once muscle mass is severely reduced will the ratio shift back towards fat again. This is a large part of the reason that anorexics have so little muscle definition. Their bodies canabilized their muscle tissue first, and when they kept starving themselves because they still saw body fat, it then broke down the fat reserves. Starvation mode is not a myth, but is severely misunderstood. Intermittent fasting does not disprove starvation mode.

SkimFlatWhite68

I'd also like to add a special message to anyone over 50 who might read this post. The older we get the more bone and muscle mass we lose; therefore, it is essential you eat no less than what your body requires to function and strength train using a moderate amount of weight.

Nice one. Nothing to do with the thread but I'll add - eat adequate amounts of Protein, Vitamin C, D, Calcium and Magnesium to help ward off the ill effects of Menopause and Osteoporosis. Also helped by strength training, as mentioned above.

SurfyFriend

Isn't "mode" a technology term? We are not robots so we don't have "modes".
If we don't eat enough food we starve, yes.

grimendale

Isn't "mode" a technology term? We are not robots so we don't have "modes".
If we don't eat enough food we starve, yes.

mode [ mōd ] 1.manner or form: a way, manner, or form, e.g. a way of doing something, or the form in which something exists
2.style or fashion: a style or fashion, e.g. in art or in dress
3.machine setting: a setting or function on a machine such as a computer

That's one definition. However, the first definition more accurately applies in this case. Starvation mode is the way, manner or form of storing and burning calories used by your body under large, long term deficits.

yarwell

Fasting is not the same as starvation mode. When people use intermittent fasting, it is the intermittent part that is the key. Your body will not enter starvation mode in a matter of days, so fasting is not going to do metabolic damage. Maintaining excessive deficits over a long term (weeks or months) will cause a change. Your statement that we carry more fat than anything else is categorically incorrect.

I meant as calories. 160 lb woman, 40% fat, 64 lb fat = 224,000 calories. Way more than any other reserve.

We carry far more muscle (assuming you are at a healthy weight).

I'm not sure people looking to lose weight are at a healthy weight, but setting that aside we're mainly water and the amount of muscle is very likely to be less than the amount of fat in overweight or obese people http://www.jawon.com/reng/res/body-composition.html

Starvation mode is not a myth, but is severely misunderstood. Intermittent fasting does not disprove starvation mode.

You did have an epic comprehension fail. I did not mention intermittent fasting at all, I referred to analysis of total fasting ( surely counts as "starvation" ) which shows fat as the primary energy source. That evidence clearly shows that muscle is not the "go to fuel" but it is catabolised to provide amino acids to fuel gluconeogenesis in the absence of dietary protein.

So an overweight dieter eating adequate protein will use and hence lose largely fat, as demonstrated in countless VLCD clinical studies.

Here's the fuel supply during fasting ie no food - maximum deficit :-

https://dl.dropboxusercontent.com/u/18312762/fastingfuel.png

marciebrian

nice going, now she deactivated. not sure you could have been ruder. hope you have a good day

Considering someone dredged up this thread from over 2 years ago the OP quite likely left a long time ago.

You're probably right but still no excuse for calling people stupid.