Body Fat vs. Deitary Fat - How much of each is my body actually burning for fuel page

[brahnamin]

Can anyone give me an idea (ballpark figure is fine) of the percentage of dietary fat vs stored body fat that your body is apt to use when eating primal?


I'm seeing results, but I'm also trying to explain to my wife what I'm doing and she keeps insisting that my body is mostly using the fat I'm eating versus the fat I'm storing as fuel.


I'm losing weight, so I figure something is burning off, but I'm too fresh into this to effectively quantify anything.


Anyone got a good answer or an easy layman's way of explaining what our bodies are doing as far as burning fat on a high fat diet?

[thebkon]

I am not sure of the ratio nor am I sure if a solid one exists. What I can say is that once your body is used to burning fat (dietary or body) then it will burn what ever fat it has access to (so long as no sugars are thrown onto the fire).


Correct me if I am wrong.

[SerialSinner]

In a low-carb diet, and when in need of energy, stored fats are used for fuel via ketosis.


Fats acquired from diet are, as far as I know, broken down into ketones as well.


Once energy needs are met, excess ketones can't be stored back as fat, so they are excreted through urine and breath.


My take is that the fat in adipose tissues tends to be more readily used as a source of ketones than dietary fats. This would explain how we lose weight in spite of going over 2k+ calories a day.


I'm not 100% sure though.

[SerialSinner]

Edit: Just confirmed that that the storage of dietary fat in adipose tissues is catalysed by the lipoprotein lipase, which is itself stimulated by insulin.


Therefore, a low-carb diet resulting in low insulin levels will result in the breakup and excretion of excess dietary fats and not in it's storage as part of adipose tissue.


Please correct me if I'm wrong.

[deepthought]

to make it simple, if your insulin levels are low(and you stay low on carbs) you are constantly "shifting" fat in and out of you cells. Taubes sais: "fat in the cells of the adipose tissue is in a continual state of flux" GCBC p.383 it also takes a special substance to "lock" the fat in the fat cells, "alpha-glycerol-fosfate". This molecule converts free fatty acids in your fat cells into triglycerides, with keeps them within the cell ie stopping the "flux". AGF is made from the liver burning sugar! reduce sugar, your AGF level will decrease and your fats can "flow"


to get back to the original question: when eating high fat, you take away the "fat locking" effect since high insulin does not push fat into the cells, and low levels of AGP makes the storing impossible. Fat "flows" and and adipose tissue is reduced.


Was it simple

[brahnamin]

Okay, I think I get it now. The trick will be to see if I can make it simple enough for my wife to understand. She goes into *Atkins Alarm* anytime I even try to broach the subject.


I appreciate all the responses. You guys really make it easy to be the newbie around here and that's not been my experience most places on the web. Thanks.

[Nick]

There's another mechanism for fat storage called acylation stimulating protein. I've already linked to Dave Dixon's article about it on another thread, but I'll link it again: http://sparkofreason.blogspot.com/2008/06/swift-kick-in-asp.html


Supposedly it only works for subcutaneous (love handles and so on), not visceral (pot belly) fat. Which is why even native peoples who don't eat carbs can still be a little pudgy, they don't all have 8 packs, etc. It's not in an Inuit's best interest to really be 6% body fat.


It's not really something to worry about stalling your progress; insulin effects dominate in most modern people. It's just good evidence that you won't waste away and die if you don't eat carbs, because your body can still store fat without them. Not only because protein releases a little bit of insulin, but because it just makes good sense from an evolutionary standpoint: even people who only ate meat and fat needed to have some ability, however minimal, to store calories for later, and maybe fatten up a bit for winter.

[Jedi]

I think its worth remembering that the PB is not excatly low carb, at least not for maintenance. Mark suggests 100-150gr of carbs per day for maintenance, that's not low carb in my book.

[SerialSinner]

brahnamin how about this: the body can manage to get rid of excess fat and protein from diet, but not glucose (unless you are a diabetic).


It makes sense to think that the body would strive to persist in an optimal physical state (obesity brings obvious short-term survival disadvantages) even in times of food abundance. as far as I know, we never see obese animals in the wild (we do see obese domesticated animals though (starch?)), regardless of how abundant food might be.


However, since very high quality foods such as sources rich in glucose where scarce, we evolved to take the most out of it upon consuming it. There was no risk of becoming obese from them due to their low availability.


In short, Grok never counted calories and probably gorged on whatever he found, and couldn't afford an inefficient physical state such as obesity due to it's survival disadvantages. Sugar, available today in massive daily quantities, breaks this balance.

[erik.cisler]

I've noticed Lyle Macdonald, who seems to detest Taubes, often cites ASP as proof that the insulin-fat storage thesis is incorrect. People seem unwilling to grasp that while calories do matter to some extent (see ASP), it's the quality of calories that matters most. I mean, it's not like we're claiming we can eat 10,000 calories of fat a day and not gain an ounce; we're just claiming that 10,000 calories of carbohydrate will be way, way worse for fat accumulation.