When does the body start burning fat or muscle?
I’m a little confused on the whole specifics between the body burning fat or muscle.
What factors are in play that causes the body to choose one or the other? Or is there some type of limit (e.g. burn X calories of muscle, then move on to fat).
For example, I remember reading about how this 700 lb. guy was put in a 500 Cal/day diet, so how much fat v. muscle would he be burning to stay alive?
That’s an interesting question. I know that genetics have a lot to do with it. It sure would be nice to think that if you’re severely obese the body would burn the fat instead of the muscle it needs to move all that bulk. Question is: does the body know how much fat it’s carrying and respond appropriately? I don’t see how unless some sort of chemical signal is present.
If I remeber correctly your body holds onto fat for as long as it can, so it will actually burn muscle first and still hild onto the fat.
[quote]superpimp wrote:
If I remeber correctly your body holds onto fat for as long as it can, so it will actually burn muscle first and still hild onto the fat.[/quote]
That is not entirely true…
If you have a lot of fat to burn your body will do so…
There comes a point however where your body starts to worry about survival and will burn muscle, especially if you do not use them.
There is no survival benefit in amazing abs…
[quote]orion wrote:
There is no survival benefit in amazing abs…[/quote]
There is, however, a reproductive benefit.
[quote]remyc88 wrote:
When does the body start burning fat or muscle?[/quote]
That depends.
[quote]
I’m a little confused on the whole specifics between the body burning fat or muscle.[/quote]
That is because there aren’t very many “specifics” but rather a whole lot of variables involved that make your questions impossible to answer with a single “specific” answer.
[quote]
What factors are in play that causes the body to choose one or the other? Or is there some type of limit (e.g. burn X calories of muscle, then move on to fat).[/quote]
Factors at play as far as burning fat or muscle for energy:
age, sex, activity level, genetic metabolism, length of time since last feeding, the schedule of feeding the body is accustomed to, protein intake, fat intake, carbohydrate intake, anabolic hormone levels and possibly even time of day.
Whatever amount equalled his caloric use for his resting metabolic rate unless he was doing some sort of activity during the day based on all of those variables listed above.
Nutrient timing and how frequently you are eating will also have an effect on what your body is using for fuel.
[quote]Professor X wrote:
remyc88 wrote:
When does the body start burning fat or muscle?
That depends.
I’m a little confused on the whole specifics between the body burning fat or muscle.
That is because there aren’t very many “specifics” but rather a whole lot of variables involved that make your questions impossible to answer with a single “specific” answer.
What factors are in play that causes the body to choose one or the other? Or is there some type of limit (e.g. burn X calories of muscle, then move on to fat).
Factors at play as far as burning fat or muscle for energy:
age, sex, activity level, genetic metabolism, length of time since last feeding, the schedule of feeding the body is accustomed to, protein intake, fat intake, carbohydrate intake, anabolic hormone levels and possibly even time of day.
For example, I remember reading about how this 700 lb. guy was put in a 500 Cal/day diet, so how much fat v. muscle would he be burning to stay alive?
Whatever amount equalled his caloric use for his resting metabolic rate unless he was doing some sort of activity during the day based on all of those variables listed above.[/quote]
So Professor X,
How long would it take for a fat person to starve? If you weighed 500lbs would you live for like 2 months with no food as opposed to a normal sized person?
Or would their poor, or most likely poor physical state cash them in faster?
[quote]OctoberGirl wrote:
Professor X wrote:
remyc88 wrote:
When does the body start burning fat or muscle?
That depends.
I’m a little confused on the whole specifics between the body burning fat or muscle.
That is because there aren’t very many “specifics” but rather a whole lot of variables involved that make your questions impossible to answer with a single “specific” answer.
What factors are in play that causes the body to choose one or the other? Or is there some type of limit (e.g. burn X calories of muscle, then move on to fat).
Factors at play as far as burning fat or muscle for energy:
age, sex, activity level, genetic metabolism, length of time since last feeding, the schedule of feeding the body is accustomed to, protein intake, fat intake, carbohydrate intake, anabolic hormone levels and possibly even time of day.
For example, I remember reading about how this 700 lb. guy was put in a 500 Cal/day diet, so how much fat v. muscle would he be burning to stay alive?
Whatever amount equalled his caloric use for his resting metabolic rate unless he was doing some sort of activity during the day based on all of those variables listed above.
So Professor X,
How long would it take for a fat person to starve? If you weighed 500lbs would you live for like 2 months with no food as opposed to a normal sized person?
Or would their poor, or most likely poor physical state cash them in faster?
[/quote]
The weird thing is, it is possible they could live for over a month or two without food, especially if they found a source of water. Water is the most important resource for us as we can die from lack of it in less than a week but survive for weeks without food.
This article is interesting about starving refugees.
http://www.unhcr.org/publ/PUBL/4135c2434.html
Though I haven’t seen any studies done on it, it wouldn’t surprise me if someone hugely obese could survive more than two months without food.
[quote]Professor X wrote:
OctoberGirl wrote:
Professor X wrote:
remyc88 wrote:
When does the body start burning fat or muscle?
That depends.
I’m a little confused on the whole specifics between the body burning fat or muscle.
That is because there aren’t very many “specifics” but rather a whole lot of variables involved that make your questions impossible to answer with a single “specific” answer.
What factors are in play that causes the body to choose one or the other? Or is there some type of limit (e.g. burn X calories of muscle, then move on to fat).
Factors at play as far as burning fat or muscle for energy:
age, sex, activity level, genetic metabolism, length of time since last feeding, the schedule of feeding the body is accustomed to, protein intake, fat intake, carbohydrate intake, anabolic hormone levels and possibly even time of day.
For example, I remember reading about how this 700 lb. guy was put in a 500 Cal/day diet, so how much fat v. muscle would he be burning to stay alive?
Whatever amount equalled his caloric use for his resting metabolic rate unless he was doing some sort of activity during the day based on all of those variables listed above.
So Professor X,
How long would it take for a fat person to starve? If you weighed 500lbs would you live for like 2 months with no food as opposed to a normal sized person?
Or would their poor, or most likely poor physical state cash them in faster?
The weird thing is, it is possible they could live for over a month or two without food, especially if they found a source of water. Water is the most important resource for us as we can die from lack of it in less than a week but survive for weeks without food.
This article is interesting about starving refugees.
http://www.unhcr.org/publ/PUBL/4135c2434.html
Though I haven’t seen any studies done on it, it wouldn’t surprise me if someone hugely obese could survive more than two months without food.[/quote]
Thanks for the link, that is a scary statistic about the water. I live in San Diego where we are always in drought conditions, or rather, what is a drought condition for us. I feel as if I am water conscious, I can only imagine what it must be like to be thirsty and not be able to drink, not because you are stuck in your car on the freeway but because there literally is no water.
And also interesting was that those refugees, who probably aren’t obese, can live for weeks without food.
the body is amazing.
[quote]Kruiser wrote:
That’s an interesting question. I know that genetics have a lot to do with it. It sure would be nice to think that if you’re severely obese the body would burn the fat instead of the muscle it needs to move all that bulk. Question is: does the body know how much fat it’s carrying and respond appropriately? I don’t see how unless some sort of chemical signal is present.[/quote]
The body does know how much fat it is carrying around. The hormone secreted by fat is called Leptin and studies have show that one of many things it does is influence the body?s energy expenditure to some extent.
[quote]Professor X wrote:
Though I haven’t seen any studies done on it, it wouldn’t surprise me if someone hugely obese could survive more than two months without food.[/quote]
I’d agree, as long as the person is getting adequate water, vitamins and minerals their fat reserves should be able to sustain them until they are all used up. Otherwise what would be the point of storing fat in the first place?
If there is 9 Kcal/gram of Fat
and there are 454 grams to a pound
than there are 4,086 kcal/lb of body fat.
Assuming a starving persons metabolism would slow down significantly. Lets assume they are only burning 1000 kcal/day.
If they had 200 lbs of excess body fat then that person would theoretically only burn 1 lb. every 4 days. That means they could live for 800 days. Or 2 years and 2 months without eating any food.
That doesn’t sound right.
Lets see, if the fat hormone Leptin works like some say it does than maybe that persons metabolism wouldn’t slow down that much seeing that they have so much stored energy. So lets say they continued to burn 2500 kcals/day.
Then they would burn 1 lb. every 1.6 days and they could survive 326 days or 10 months. That sounds more possible.
But as the body lost fat it would burn fewer calories so they might be able to live slightly longer.
how does that sound?
There have been a few documented instances in which people have gone on hunger strikes for up to 120 days. These were probably fairly normal weight people. Not morbidly obese like my example. But water, vitamins and minerals would be crucial.
Assuming they had water and minerals I would imagine that their protein stores (muscle) necessary for upkeep would be exhausted before their ample fat stores.
Ever notice the prisoners of the WW2 Japanese, on a diet of rice and hard labor, still held on to some fat but lost vast amounts of muscle…(No way to get “cut” there)…
[quote]Professor X wrote:
Water is the most important resource for us…[/quote]
I had my money on oxygen.
[quote]pookie wrote:
Professor X wrote:
Water is the most important resource for us…
I had my money on oxygen.[/quote]
Well, if you want to go there, where we would be without anything to stand on? Therefore, Earth is our greatest resource for providing land.
[quote]Professor X wrote:
Well, if you want to go there, where we would be without anything to stand on?[/quote]
In the same place you eventually find yourself in every argument?
[quote]pookie wrote:
Professor X wrote:
Well, if you want to go there, where we would be without anything to stand on?
In the same place you eventually find yourself in every argument?
[/quote]
This was an argument? You jumped into a thread about STARVATION and pointed out (oh so cleverly) that humans need oxygen. Well, if that don’t win the debate hands down I don’t know what does.
You’re right. You win. You beat me. I am so defeated.
“Oxygen”. What a whopper!!
We didn’t learn a thing about oxygen at all in classes through school. We just kept inhaling while remaining mystified at our ability to keep living.
[quote]pookie wrote:
Professor X wrote:
Well, if you want to go there, where we would be without anything to stand on?
In the same place you eventually find yourself in every argument?
[/quote]
ROFLMAO!!!
[quote]Professor X wrote:
We just kept inhaling while remaining mystified at our ability to keep living.[/quote]
Are you sure? You do exhibit many of the signs of prolonged oxygen-deprivation.
Although it’s probably because of your propensity for immediately converting most of it to hot air.