Do you burn FAT or MUSCLE? How do you know?

[johntaylorny]

Just out of curiosity... if you are looking to burn fat and lose weight and you are consuming a calorie deficit how does your body know to burn fat or muscle for fuel? Of course I'd rather it burn fat. That's what I want to know.

[snacker]

Keep protein intake high if you're going calorie deficit. Best way to keep muscle loss to minimum while losing weight.

[weiss1967]

Just out of curiosity... if you are looking to burn fat and lose weight and you are consuming a calorie deficit how does your body know to burn fat or muscle for fuel? Of course I'd rather it burn fat. That's what I want to know.

One way to spare muscle and burn fat is by switching your metabolism to fat-burning mode through ketogenic diet. Do some reading on this. In a nutshell - you eat fat to burn fat.

[EjnarKolinkar]

You send the body stimulus to keep the muscle by training and eat properly.

This has some good general info:

http://www.bodyrecomposition.com/mus...mass-gain.html

[Plateauplower]

Fat is simply energy stored for later use. Your body will prefer to burn fat for energy over muscle. However by lifting heavy and maintaining adequate protein intake will help ensure that. There are essential amino acids that cannot be made in the body, if complete protein sources were absent in diet, some muscle may be broken down to get these amino acids to repair more important tissues (organs etc). At higher body fat levels muscle loss is likely not as much of an issue as it is with people who are already lean and trying to get single digit body fat.

[hmmmm16417]

Fat is simply energy

lol that's why fat people are so energetic?

Jk

[SideSteal]

One way to spare muscle and burn fat is by switching your metabolism to fat-burning mode through ketogenic diet. Do some reading on this. In a nutshell - you eat fat to burn fat.

There's an inherent flaw with this logic though, in that on a ketogenic diet fat intake is significantly higher. So yes, you burn more fat, but you also eat more fat.

http://www.bodyrecomposition.com/fat...rn-fat-qa.html
http://www.bodyrecomposition.com/nut...oxidation.html




Generally speaking, people don't really need to be concerned with acute fat oxidation. As long as you are in a net energy deficit and getting in sufficient macronutrients for your goals, fat oxidation over the long term will exceed fat storage and you will end up with a net loss of fat.

[JWoodCF10]

The human body as and evolutionary machine is not designed to destroy its muscles. They are the fuel of last resort. There is one reason however that the body will start to break down muscle fibres but its rare.
If the body needs electrolytes it may break down the amino acids in muscle to find them. Otherwise after glycogen, fat is the next best thing.

The ketogenic diet is not so much as eating loads of fat, but cutting back on sugar to ensure that there is low to zero insulin levels in the body. Yes you get into ketosis quickly by eating loads of fat, but once there you can calorie restrict happily to burn off fat stores. :-)

[pastorgbc]

There's an inherent flaw with this logic though, in that on a ketogenic diet fat intake is significantly higher. So yes, you burn more fat, but you also eat more fat.

http://www.bodyrecomposition.com/fat...rn-fat-qa.html
http://www.bodyrecomposition.com/nut...oxidation.html




Generally speaking, people don't really need to be concerned with acute fat oxidation. As long as you are in a net energy deficit and getting in sufficient macronutrients for your goals, fat oxidation over the long term will exceed fat storage and you will end up with a net loss of fat.

Yes, but it takes much more fat to generate your body's energy needs than it does sugars. The theory of the ketogenic diet is that you cannot consume so much fat that you will overwhelm your body and it will store fat as well. I know people who put that to the test.

One of the truths of the matter is that if you basically eliminate a macro group, it becomes difficult to eat at a surplus, thus you lose weight. If you are in ketosis, the body is actively burning fat for energy. However, the burning of nutrients for energy is not a linear progression (I.e., carbs, then fats, then protein), but it becomes a combo factor based on many things, not the least of which is amount of body at a person has.

The bottom line is that if you are on a drastic diet that eliminates a food group, it becomes very difficult not to burn some muscle. Certainly, hitting your protein requirements is essential to mitigating this.

Ray

[SideSteal]

Yes, but it takes much more fat to generate your body's energy needs than it does sugars.
Ray

Couldn't you argue the opposite given that fat has higher energy density?

[pastorgbc]

Couldn't you argue the opposite given that fat has higher energy density?

You could argue it all you want; it doen't change the truth. Burning fat for energy is not nearly as efficient as burning carbs and it is an incomplete process. This is why when the body is in ketosis, ketone bodies (residual fat particles) are present in the blood stream.

Ray

[JWoodCF10]

Yes, but it takes much more fat to generate your body's energy needs than it does sugars. The theory of the ketogenic diet is that you cannot consume so much fat that you will overwhelm your body and it will store fat as well. I know people who put that to the test.

One of the truths of the matter is that if you basically eliminate a macro group, it becomes difficult to eat at a surplus, thus you lose weight. If you are in ketosis, the body is actively burning fat for energy. However, the burning of nutrients for energy is not a linear progression (I.e., carbs, then fats, then protein), but it becomes a combo factor based on many things, not the least of which is amount of body at a person has.

The bottom line is that if you are on a drastic diet that eliminates a food group, it becomes very difficult not to burn some muscle. Certainly, hitting your protein requirements is essential to mitigating this.

Ray

Most fat in the body (nearly all) comes from excess carbohydrate. If we ingest to much fat, i.e. more than we can handle we end up with steatorrhea (or fatty cannon but LOL).

For the body to convert ingested fats to stored fats is quite a long winded biosynthetic pathway, which mostly does not happen. I have spoken to many people who have lost a lot of weight eating massive calorie excesses but as there carbs were so low <20gm / day, they had tiny amounts of insulin so there was no drive to store energy.

Biochemistry I find fascinating, and that couple with how the human evolved makes diet and nutrition one of the most interesting sciences there is :-)

[SideSteal]

Most fat in the body (nearly all) comes from excess carbohydrate. If we ingest to much fat, i.e. more than we can handle we end up with steatorrhea (or fatty cannon but LOL).

For the body to convert ingested fats to stored fats is quite a long winded biosynthetic pathway, which mostly does not happen.

Are you claiming that DNL is the most common cause of fat gain in most people rather than dietary fat storage?

[JWoodCF10]

Are you claiming that DNL is the most common cause of fat gain in most people rather than dietary fat storage?

Nae idea what DNL is I'm afraid.

The reason for dietary fat storage is an excess of energy in the body, the energy most commonly stored as fat comes from the carbs.

Body fat biosynth pathway is normally:

Starch's going to Glucose going to Pyruvate going to Acetyl CoA going to Fatty acids Going to Triglycerides.

edit:
DNL as in de-novo lipogenesis. then yes that IS how fat is stored. To put it into perspective. If you were to take some adipose tissue from vegetarian and compare it to life long Atkins dieter, you would find that both were basically made out of exactly the same thing Palmitic and stearic acid. Or saturated fats. Plats normally make unsaturated fats, either mono or poly unsaturated.

Again this is purely a physiological thing, as it would be a bit rubbish if our fat storage was liquid at body temperature LOL.

[TacoTommy11]

As mention a couple times. The body prefers to burn fat for energy after glycogen. If you eat at least your minimum amount of protein it will help retain muscle loss if you are on a cut or eating a calorie deficit.

I'd like to add eating a calorie surplus is what causes the body to store fat, not eating fat. Its simply calories in vs calories out. Fatty food have a lot of calories so too many, and you will be eating at a surplus. You eat less calories then your TDEE you lose fat, you eat more...you gain some fat and muscle if you are resistance training, you eat exactly your TDEE you maintain.

[weiss1967]

Just out of curiosity... if you are looking to burn fat and lose weight and you are consuming a calorie deficit how does your body know to burn fat or muscle for fuel? Of course I'd rather it burn fat. That's what I want to know.

another theory is that your calorific deficit must be small enough, like no more than 500 calories below maintenance if you want to spare the muscle. But this part is difficult, small deficit means very slow rates of fat loss, something like 0.5 pound to one pound / week.

[SideSteal]

I'd like to add eating a calorie surplus is what causes the body to store fat, not eating fat.

Absolutely. The previous discussion/confusion was around mechanisms by which fat accumulation occurs, whether it's through DNL or direct storage.

[SideSteal]

Nae idea what DNL is I'm afraid.

The reason for dietary fat storage is an excess of energy in the body, the energy most commonly stored as fat comes from the carbs.

Body fat biosynth pathway is normally:

Starch's going to Glucose going to Pyruvate going to Acetyl CoA going to Fatty acids Going to Triglycerides.

edit:
DNL as in de-novo lipogenesis. then yes that IS how fat is stored. To put it into perspective. If you were to take some adipose tissue from vegetarian and compare it to life long Atkins dieter, you would find that both were basically made out of exactly the same thing Palmitic and stearic acid. Or saturated fats. Plats normally make unsaturated fats, either mono or poly unsaturated.

Again this is purely a physiological thing, as it would be a bit rubbish if our fat storage was liquid at body temperature LOL.

I'm not disputing the pathway you're suggesting as I've not researched it but there's evidence that DNL does not occur at a significant rate under most conditions. (IE it doesn't account for the majority of fat storage)

Overconsumption of carbohydrate blunts fat oxidation (carb oxidation goes up, fat oxidation goes down) and increases direct fat storage rather than the carbohydrates themselves storing as fat.

[JWoodCF10]

I'm not disputing the pathway you're suggesting as I've not researched it but there's evidence that DNL does not occur at a significant rate under most conditions. (IE it doesn't account for the majority of fat storage)

Overconsumption of carbohydrate blunts fat oxidation (carb oxidation goes up, fat oxidation goes down) and increases direct fat storage rather than the carbohydrates themselves storing as fat.

Yes you are right consumption of carbs causes fat oxidation to stop, but this is an effect of insulin. Hence diabetic keto-acidosis happens.

I will look up if I can find anything about direct storage of fats, and if any fats can be directly deposited into adipose tissue. You have me genuinely interested to find out.

I'll post back when I find out :-).

What I know is that I have been on an almost zero carb very high animal fat diet since 22 march and I've lost 15 kg and 7 inch from my waist, and that is without eating a particular calorie deficit, or upping my exercise. I have been solidly pissing out ketones since 24th march, and I doubt that my body has released any insulin since then.

(Yes I know that is my own personal experience and not necessarily reproducible or particularly scientific).