Losing Muscle?

AlyssasDiet

Can someone please explain to me the science behind "If you eat too few calories, you will lose muscle (instead of fat)"? I'm having trouble finding the logic behind this. The soul purpose of fat is to be energy storage, so why would your body ever go to your muscle for energy, before going to it's designated energy stores(the fat)? I'm not looking for "because it's true!" answer, I would prefer links to actual peer reviewed studies done. :huh:

beachlover317

*Sorry was going to answer, but I don't have studies to quote to you.

psuLemon

http://forum.bodybuilding.com/showthread.php?t=127236133

Here is a good discussion on bb.com about it. This might help. I will see if I can't find more science.

neanderthin

It has to do with body fat.......lots of it, your probably not going to lose much if any muscle with adequate protein and weight resistance.........low body fat and a big deficit, then the body is going to get that deficit energy from somewhere and that's muscle.

Basically the body can liberate about 32 calories per lb of body fat, so it depends on how deep the deficit is and how much fat a person has......if someone is obese and trying to lose weight eating in a fairly big deficit with adequate protein intake, they're probably good to go. Sorry this comes up a lot and didn't feel like researching it, take it or leave my response, doesn't matter to me, said in a nice way.

Derf_Smeggle

/Edit/ It is an incorrect statement people make when they say we lose muscle *instead* of fat. Rather we can lose muscle along with fat loss. /End Edit/

This generally relates to the over all umbrella of Catabolism. Catabolism, in simple terms that I understand, is the metabolic process of breaking down of complex molecules into simpler molecules to release energy. Catabolism covers the breakdown of carbohydrates, fat, and protein that we consume. It also includes the breakdown of stored energy in the body, such as, glycogen that is stored in the liver, stored fat, and protein stored in the muscle tissue.

Our bodies really strive to maintain homeostasis. One part of this homeostasis is blood sugar, or blood glucose levels. Blood glucose levels have to be maintained so that cells can be provided with the material needed to produce ATP. Now here is the thing. The body does not actively care where it gets the glucose from. It will take from the most readily available source.

I will say this is what I understand of the following process. I stand ready to be corrected. In cases where readily available glucose from dietary calories become less available and when glycogen stores are low in the liver our bodies will activate, or perhaps it is better to say, increase the level of a process called gluconeogensis. Gluconeogensis is the breakdown of non-carbohydrate substrates to produce glucose. If your body cannot find dietary sources of fat and protein to breakdown, it starts looking at stored fat and muscle protein to breakdown.

At this point I'll repeat the body does not care where the glucose comes from, so long as it can get that blood glucose level raised.

The general consensus in my reading about the topic on catabolism of lean muscle is that a small amount will occur during dieting and calorie restriction. The method of limiting the lean muscle loss seems to revolve around eating sufficient amounts of protein in a well balanced diet, by eating small amounts of food in greater frequency, and doing some muscle building exercise.

In layman's terms that I understand it seems this works for the following reasons. By eating the right amount of protein in a balanced diet you are insuring there is a quicker, easier source of protein to go to for the catabolic processes. By eating frequently in small amounts you are insuring there is always a little something to "burn" before going to look for it in the muscle. By doing some muscle building exercise you are signaling the body that the protein bound up in the muscles is needed where it is at.

Derf_Smeggle

Basically the body can liberate about 32 calories per lb of body fat, so it depends on how deep the deficit is and how much fat a person has....

I question this number. 1 gram of fat contains an average of 9 calories (kCal if we're being really precise). 1 pound is 454 grams, decimals aside. 1 pound (454 grams) of body fat is on average 87% lipid. 454g * 87% * 9 = 3555 calories.

eric_sg61

Are you implying the body only runs on fat as its fuel source? You'll always lose some muscle in calorie restriction. Research pubmed, be warned this area is very broad

Here are some
http://www.ncbi.nlm.nih.gov/pubmed/16526835
http://www.ncbi.nlm.nih.gov/pubmed/23446962

happystars82

ok just when i think i understand something i then get confused again..

i'm 242lb i have a 1000 cals a day deficit i burn on adverage 800 cals 4 times a week and i have gained a 1lb!
i was told this is because of muscle built from gym.... my body must of been burning fat as i have lost inches.. so is it right if you have a deficit and are using muscle then your engery source will be body fat especially someone of my size? would that also explain how i have put on weight....?

one confused little lady from the UK
p.s feel free to add and inbox to explain this more if you like...

eric_sg61

ok just when i think i understand something i then get confused again..

i'm 242lb i have a 1000 cals a day deficit i burn on adverage 800 cals 4 times a week and i have gained a 1lb!
i was told this is because of muscle built from gym.... my body must of been burning fat as i have lost inches.. so is it right if you have a deficit and are using muscle then your engery source will be body fat especially someone of my size? would that also explain how i have put on weight....?

one confused little lady from the UK
p.s feel free to add and inbox to explain this more if you like...

Not sure if this applies to you but:
http://www.bodyrecomposition.com/fat-loss/why-big-caloric-deficits-and-lots-of-activity-can-hurt-fat-loss.html

AlyssasDiet

/Edit/ It is an incorrect statement people make when they say we lose muscle *instead* of fat. Rather we can lose muscle along with fat loss. /End Edit/

This generally relates to the over all umbrella of Catabolism. Catabolism, in simple terms that I understand, is the metabolic process of breaking down of complex molecules into simpler molecules to release energy. Catabolism covers the breakdown of carbohydrates, fat, and protein that we consume. It also includes the breakdown of stored energy in the body, such as, glycogen that is stored in the liver, stored fat, and protein stored in the muscle tissue.

Our bodies really strive to maintain homeostasis. One part of this homeostasis is blood sugar, or blood glucose levels. Blood glucose levels have to be maintained so that cells can be provided with the material needed to produce ATP. Now here is the thing. The body does not actively care where it gets the glucose from. It will take from the most readily available source.

I will say this is what I understand of the following process. I stand ready to be corrected. In cases where readily available glucose from dietary calories become less available and when glycogen stores are low in the liver our bodies will activate, or perhaps it is better to say, increase the level of a process called gluconeogensis. Gluconeogensis is the breakdown of non-carbohydrate substrates to produce glucose. If your body cannot find dietary sources of fat and protein to breakdown, it starts looking at stored fat and muscle protein to breakdown.

At this point I'll repeat the body does not care where the glucose comes from, so long as it can get that blood glucose level raised.

The general consensus in my reading about the topic on catabolism of lean muscle is that a small amount will occur during dieting and calorie restriction. The method of limiting the lean muscle loss seems to revolve around eating sufficient amounts of protein in a well balanced diet, by eating small amounts of food in greater frequency, and doing some muscle building exercise.

In layman's terms that I understand it seems this works for the following reasons. By eating the right amount of protein in a balanced diet you are insuring there is a quicker, easier source of protein to go to for the catabolic processes. By eating frequently in small amounts you are insuring there is always a little something to "burn" before going to look for it in the muscle. By doing some muscle building exercise you are signaling the body that the protein bound up in the muscles is needed where it is at.

Thank you for taking the time to write all of that out! I'm starting to get t now. So it's more of a nutrients thing than a calorie thing. Which means I who eat (to be honest) way too much protein and exercise alongside my diet, shouldn't have to worry about losing any muscle?

AlyssasDiet

Are you implying the body only runs on fat as its fuel source? You'll always lose some muscle in calorie restriction. Research pubmed, be warned this area is very broad

Here are some
http://www.ncbi.nlm.nih.gov/pubmed/16526835
http://www.ncbi.nlm.nih.gov/pubmed/23446962

Thank you for these studies! They were very interesting and exactly what I was looking for!

psuLemon

ok just when i think i understand something i then get confused again..

i'm 242lb i have a 1000 cals a day deficit i burn on adverage 800 cals 4 times a week and i have gained a 1lb!
i was told this is because of muscle built from gym.... my body must of been burning fat as i have lost inches.. so is it right if you have a deficit and are using muscle then your engery source will be body fat especially someone of my size? would that also explain how i have put on weight....?

one confused little lady from the UK
p.s feel free to add and inbox to explain this more if you like...

your weight gain is most likely due to water retention.

happystars82

ok just when i think i understand something i then get confused again..

i'm 242lb i have a 1000 cals a day deficit i burn on adverage 800 cals 4 times a week and i have gained a 1lb!
i was told this is because of muscle built from gym.... my body must of been burning fat as i have lost inches.. so is it right if you have a deficit and are using muscle then your engery source will be body fat especially someone of my size? would that also explain how i have put on weight....?

one confused little lady from the UK
p.s feel free to add and inbox to explain this more if you like...

Not sure if this applies to you but:
http://www.bodyrecomposition.com/fat-loss/why-big-caloric-deficits-and-lots-of-activity-can-hurt-fat-loss.html

it says the link has expired?

happystars82

ok just when i think i understand something i then get confused again..

i'm 242lb i have a 1000 cals a day deficit i burn on adverage 800 cals 4 times a week and i have gained a 1lb!
i was told this is because of muscle built from gym.... my body must of been burning fat as i have lost inches.. so is it right if you have a deficit and are using muscle then your engery source will be body fat especially someone of my size? would that also explain how i have put on weight....?

one confused little lady from the UK
p.s feel free to add and inbox to explain this more if you like...

your weight gain is most likely due to water retention.

after a month?

psuLemon

ok just when i think i understand something i then get confused again..

i'm 242lb i have a 1000 cals a day deficit i burn on adverage 800 cals 4 times a week and i have gained a 1lb!
i was told this is because of muscle built from gym.... my body must of been burning fat as i have lost inches.. so is it right if you have a deficit and are using muscle then your engery source will be body fat especially someone of my size? would that also explain how i have put on weight....?

one confused little lady from the UK
p.s feel free to add and inbox to explain this more if you like...

your weight gain is most likely due to water retention.

after a month?

I just looked at your diary. I bet you are eating a lot more calories than you think you are. You are not consistent with your logging. Also, if you aren't using a food scale, it's another way it could be off. If you want to discuss further, PM me.


OP, sorry about the small hijack.

Bejede

Bump

eric_sg61

ok just when i think i understand something i then get confused again..

i'm 242lb i have a 1000 cals a day deficit i burn on adverage 800 cals 4 times a week and i have gained a 1lb!
i was told this is because of muscle built from gym.... my body must of been burning fat as i have lost inches.. so is it right if you have a deficit and are using muscle then your engery source will be body fat especially someone of my size? would that also explain how i have put on weight....?

one confused little lady from the UK
p.s feel free to add and inbox to explain this more if you like...

Not sure if this applies to you but:
http://www.bodyrecomposition.com/fat-loss/why-big-caloric-deficits-and-lots-of-activity-can-hurt-fat-loss.html

it says the link has expired?

Works fine on my end. Make sure you entered it right.

psuLemon

/Edit/ It is an incorrect statement people make when they say we lose muscle *instead* of fat. Rather we can lose muscle along with fat loss. /End Edit/

This generally relates to the over all umbrella of Catabolism. Catabolism, in simple terms that I understand, is the metabolic process of breaking down of complex molecules into simpler molecules to release energy. Catabolism covers the breakdown of carbohydrates, fat, and protein that we consume. It also includes the breakdown of stored energy in the body, such as, glycogen that is stored in the liver, stored fat, and protein stored in the muscle tissue.

Our bodies really strive to maintain homeostasis. One part of this homeostasis is blood sugar, or blood glucose levels. Blood glucose levels have to be maintained so that cells can be provided with the material needed to produce ATP. Now here is the thing. The body does not actively care where it gets the glucose from. It will take from the most readily available source.

I will say this is what I understand of the following process. I stand ready to be corrected. In cases where readily available glucose from dietary calories become less available and when glycogen stores are low in the liver our bodies will activate, or perhaps it is better to say, increase the level of a process called gluconeogensis. Gluconeogensis is the breakdown of non-carbohydrate substrates to produce glucose. If your body cannot find dietary sources of fat and protein to breakdown, it starts looking at stored fat and muscle protein to breakdown.

At this point I'll repeat the body does not care where the glucose comes from, so long as it can get that blood glucose level raised.

The general consensus in my reading about the topic on catabolism of lean muscle is that a small amount will occur during dieting and calorie restriction. The method of limiting the lean muscle loss seems to revolve around eating sufficient amounts of protein in a well balanced diet, by eating small amounts of food in greater frequency, and doing some muscle building exercise.

In layman's terms that I understand it seems this works for the following reasons. By eating the right amount of protein in a balanced diet you are insuring there is a quicker, easier source of protein to go to for the catabolic processes. By eating frequently in small amounts you are insuring there is always a little something to "burn" before going to look for it in the muscle. By doing some muscle building exercise you are signaling the body that the protein bound up in the muscles is needed where it is at.

Thank you for taking the time to write all of that out! I'm starting to get t now. So it's more of a nutrients thing than a calorie thing. Which means I who eat (to be honest) way too much protein and exercise alongside my diet, shouldn't have to worry about losing any muscle?

How much weight/resistance training do you do? Regardless of how keen you are with nutrition and exercise, you will lose some amount of lean body mass. A small deficit and adequate protein will decrease the amount of muscle loss, but a threshold of 10-20% isn't uncommon.

I will note, I have seen up to 50% loss in cases of LCD (person lost 40% but then again she was eating like 800 calories a day)

danimalkeys

ok just when i think i understand something i then get confused again..

i'm 242lb i have a 1000 cals a day deficit i burn on adverage 800 cals 4 times a week and i have gained a 1lb!
i was told this is because of muscle built from gym.... my body must of been burning fat as i have lost inches.. so is it right if you have a deficit and are using muscle then your engery source will be body fat especially someone of my size? would that also explain how i have put on weight....?

one confused little lady from the UK
p.s feel free to add and inbox to explain this more if you like...

your weight gain is most likely due to water retention.

after a month?

Yes, even after a month- you retain water when you work out so your body can repair the muscles. It's much more likely that you've gained water weight than gained 1lb of muscle in a month while eating at a deficit. Building muscle needs a surplus of calories and a lot of hard work in the gym, and even then the gains are not 1lb a month, at least, in women who have a harder time putting muscle mass on.

Derf_Smeggle

Thank you for taking the time to write all of that out! I'm starting to get t now. So it's more of a nutrients thing than a calorie thing. Which means I who eat (to be honest) way too much protein and exercise alongside my diet, shouldn't have to worry about losing any muscle?

Not exactly. Some lean body mass loss is going to occur, but by eating the proper amounts of protein and by doing muscle building/weight training exercises you will reduce the amount of lean mass loss. You will also build overall muscle mass by causing the muscle cells to become hypertrophic.

Basically, don't drive yourself nuts about the minor lean body mass loss. Eat properly. Workout. Enjoy your success!

Derf_Smeggle

ok just when i think i understand something i then get confused again..

i'm 242lb i have a 1000 cals a day deficit i burn on adverage 800 cals 4 times a week and i have gained a 1lb!
i was told this is because of muscle built from gym.... my body must of been burning fat as i have lost inches.. so is it right if you have a deficit and are using muscle then your engery source will be body fat especially someone of my size? would that also explain how i have put on weight....?

one confused little lady from the UK
p.s feel free to add and inbox to explain this more if you like...

Re-examine your calorie logging and re-examine your calculation for the calorie burn. I ran into the very same problem a couple years ago, during an earlier attempt to adjust my BMI. I broke out my food scale and my pocket notepad to check my consistency.

Realized I was significantly underestimating my calorie intake.

It is so ridiculously easy for me to underestimate, or to forget to log something.

susannamarie

Basically the body can liberate about 32 calories per lb of body fat, so it depends on how deep the deficit is and how much fat a person has....

I question this number. 1 gram of fat contains an average of 9 calories (kCal if we're being really precise). 1 pound is 454 grams, decimals aside. 1 pound (454 grams) of body fat is on average 87% lipid. 454g * 87% * 9 = 3555 calories.

They mean 32 calories per pound per day. I've seen 31 instead but close enough. IOW, you can get the whole 3500 calories -- just not all in one day.

Siansonea

So, if you're smaller overall, why would you need the same muscle mass you had when you were larger? Your body has less mass to carry around and keep upright, so wouldn't it need less muscle mass to do all that lifting and carrying? :huh:

susannamarie

So, if you're smaller overall, why would you need the same muscle mass you had when you were larger? Your body has less mass to carry around and keep upright, so wouldn't it need less muscle mass to do all that lifting and carrying? :huh:

First, losing muscle doesn't affect only the muscles that carry you around, but also muscles such as your heart, so avoiding excessive muscle loss is necessary so your body doesn't lose the necessary muscles with the no longer necessary.

Secondly, many people increase activity significantly when they lose weight, so the amount of muscle that was reasonable for the inactive obese person is still reasonable for the more active slender person.

Lastly, losing enough muscle can result in needing to lose significantly more weight to reach the desired bodyfat level/aesthetic appearance, resulting in needing to eat significantly fewer calories to maintain weight, which can cause problems with regain.

johan1585

ok just when i think i understand something i then get confused again..

i'm 242lb i have a 1000 cals a day deficit i burn on adverage 800 cals 4 times a week and i have gained a 1lb!
i was told this is because of muscle built from gym.... my body must of been burning fat as i have lost inches.. so is it right if you have a deficit and are using muscle then your engery source will be body fat especially someone of my size? would that also explain how i have put on weight....?

one confused little lady from the UK
p.s feel free to add and inbox to explain this more if you like...

Could allso be blood vollume increase

tigersword

Your body is constantly breaking down muscle tissue. During caloric maintenance, there's enough fuel coming in to repair all the muscle tissue being broken down. During a caloric deficit, there isn't. The larger the deficit, the less muscle, bone, and organ tissue can be replaced after being broken down. While strength training can help maintain a level of muscle mass during moderate deficit (by convincing the body that the muscle is a requirement for survival,) if the deficit is too large it's impossible for the body to make up the difference. Yes, your body dips into fat stores for energy purposes, however, like muscle breakdown, that occurs every second of every day, no matter how much you eat. Like muscle, if you are eating at maintenance, your body refills the fat stores that were used to maintain homeostasis. In a deficit, there isn't enough fuel to refill the fat stores. In a severe deficit, the body will actually swing toward prioritizing refilling fat stores rather than repairing muscle as a survival mechanism, as in periods of famine you can survive much longer with little muscle and lots of fat than you can with lots of muscle and little fat.

That's why small to moderate deficit plus some form of strength training tends to be the "magic formula" for long term success.

Derf_Smeggle

Basically the body can liberate about 32 calories per lb of body fat, so it depends on how deep the deficit is and how much fat a person has....

I question this number. 1 gram of fat contains an average of 9 calories (kCal if we're being really precise). 1 pound is 454 grams, decimals aside. 1 pound (454 grams) of body fat is on average 87% lipid. 454g * 87% * 9 = 3555 calories.

They mean 32 calories per pound per day. I've seen 31 instead but close enough. IOW, you can get the whole 3500 calories -- just not all in one day.

Ah-ha. I see what they were talking about now. Slightly confusing the way it was written.

Siansonea

So, if you're smaller overall, why would you need the same muscle mass you had when you were larger? Your body has less mass to carry around and keep upright, so wouldn't it need less muscle mass to do all that lifting and carrying? :huh:

First, losing muscle doesn't affect only the muscles that carry you around, but also muscles such as your heart, so avoiding excessive muscle loss is necessary so your body doesn't lose the necessary muscles with the no longer necessary.

Secondly, many people increase activity significantly when they lose weight, so the amount of muscle that was reasonable for the inactive obese person is still reasonable for the more active slender person.

Lastly, losing enough muscle can result in needing to lose significantly more weight to reach the desired bodyfat level/aesthetic appearance, resulting in needing to eat significantly fewer calories to maintain weight, which can cause problems with regain.

Oh, izzat so? I'd sure like to see the numbers we're talking about here, and rigorous scientific research about this, etc.

Siansonea

Your body is constantly breaking down muscle tissue. During caloric maintenance, there's enough fuel coming in to repair all the muscle tissue being broken down. During a caloric deficit, there isn't. The larger the deficit, the less muscle, bone, and organ tissue can be replaced after being broken down. While strength training can help maintain a level of muscle mass during moderate deficit (by convincing the body that the muscle is a requirement for survival,) if the deficit is too large it's impossible for the body to make up the difference. Yes, your body dips into fat stores for energy purposes, however, like muscle breakdown, that occurs every second of every day, no matter how much you eat. Like muscle, if you are eating at maintenance, your body refills the fat stores that were used to maintain homeostasis. In a deficit, there isn't enough fuel to refill the fat stores. In a severe deficit, the body will actually swing toward prioritizing refilling fat stores rather than repairing muscle as a survival mechanism, as in periods of famine you can survive much longer with little muscle and lots of fat than you can with lots of muscle and little fat.

That's why small to moderate deficit plus some form of strength training tends to be the "magic formula" for long term success.

Quite a claim. Evidence?

neanderthin

Your body is constantly breaking down muscle tissue. During caloric maintenance, there's enough fuel coming in to repair all the muscle tissue being broken down. During a caloric deficit, there isn't. The larger the deficit, the less muscle, bone, and organ tissue can be replaced after being broken down. While strength training can help maintain a level of muscle mass during moderate deficit (by convincing the body that the muscle is a requirement for survival,) if the deficit is too large it's impossible for the body to make up the difference. Yes, your body dips into fat stores for energy purposes, however, like muscle breakdown, that occurs every second of every day, no matter how much you eat. Like muscle, if you are eating at maintenance, your body refills the fat stores that were used to maintain homeostasis. In a deficit, there isn't enough fuel to refill the fat stores. In a severe deficit, the body will actually swing toward prioritizing refilling fat stores rather than repairing muscle as a survival mechanism, as in periods of famine you can survive much longer with little muscle and lots of fat than you can with lots of muscle and little fat.

That's why small to moderate deficit plus some form of strength training tends to be the "magic formula" for long term success.

QFT

tigersword

Your body is constantly breaking down muscle tissue. During caloric maintenance, there's enough fuel coming in to repair all the muscle tissue being broken down. During a caloric deficit, there isn't. The larger the deficit, the less muscle, bone, and organ tissue can be replaced after being broken down. While strength training can help maintain a level of muscle mass during moderate deficit (by convincing the body that the muscle is a requirement for survival,) if the deficit is too large it's impossible for the body to make up the difference. Yes, your body dips into fat stores for energy purposes, however, like muscle breakdown, that occurs every second of every day, no matter how much you eat. Like muscle, if you are eating at maintenance, your body refills the fat stores that were used to maintain homeostasis. In a deficit, there isn't enough fuel to refill the fat stores. In a severe deficit, the body will actually swing toward prioritizing refilling fat stores rather than repairing muscle as a survival mechanism, as in periods of famine you can survive much longer with little muscle and lots of fat than you can with lots of muscle and little fat.

That's why small to moderate deficit plus some form of strength training tends to be the "magic formula" for long term success.

Quite a claim. Evidence?

Open a biology textbook? It's very basic human biology. The body goes back and forth between being anabolic (building stuff) and catabolic (tearing stuff down) on a constant basis. When you eat, you shift into anabolic mode. Once the food is digested and partitioned, the body shifts into catabolic mode. Cells die by the millions every day (sounds like a lot, but the human body contains roughly 100 trillion cells,) when they die, they get broken down and depending on what they are, may be used for fuel, or may just be eliminated. How many of those millions of cells get replaced depends on how much food is eaten. The order they get replaced in depends purely on need for survival. That's why hair loss is commonly the first symptom of starvation and malnutrition; hair is important for UV protection from the sun, but not as important as skin, bones, heart, brain, and muscles.

As for muscle vs fat partitioning, again, depending on how severe the deficit is, the body may preferentially store fat and continue to catabolize muscle in a quest for homeostasis; muscle is metabolically active, and in times of terrible famine (the human body doesn't know "dieting" it just knows food is abundant or scarce based on how much it receives) muscle is shed so that the body will need less calories for homestasis. Strength training requires the use of muscle, which forces the body to hang on to it, as again, the body doesn't understand "exercise;" it just knows that the muscles are being used and are now necessary for survival and need to be maintained.