The Science of "Starvation Mode"
MinimalistShoeAddict
Posts: 1,946 Member
The Science of "Starvation Mode"
I am not promoting any diet or particular intake level. The reason for this post is to encourage MFP members to learn more about the science behind "starvation mode". For those of you that like science I suggest reading some scientific studies on the topic. Wikipedia contains a lot of helpful citations:
http://en.wikipedia.org/wiki/Starvation_response
From Wikipedia:
"Starvation response in animals is a set of adaptive biochemical and physiological changes that reduce metabolism in response to a lack of food."
This basically means that after a certain point metabolism can slow down. Metabolism never stops as long as we are alive. The relevant question is how much metabolism slows.
From Wikipedia:
"Starvation mode is a state in which the body is responding to prolonged periods of low energy intake levels. During short periods of energy abstinence, the human body will burn primarily free fatty acids from body fat stores. After prolonged periods of starvation the body has depleted its body fat and begins to burn lean tissue and muscle as a fuel source."
Naturally, a morbidly obese person has an abundant supply of fat stores to begin with and can go a much longer period of time before burning significant lean muscle tissue for fuel (the same reason why a fat bear can hibernate for a much longer period than a bear who was lean before winter began). For this reason, scientific studies of long term very low calorie diets are ONLY conducted on overweight individuals. If someone is very lean to begin with they are at a much greater risk of losing lean muscle mass while eating under TDEE. For centuries before food became so easily available we had periods of feast and famine. During the famine period most people ate very low calorie diets. Some of them died. Who was more likely to survive? Naturally the people who were very overweight before the famine began (unlike today, for much of history it was the rich population who was obese, often by choice for this very reason). People who were very lean before the famine began often did not do well. This is the same reason very low calorie diets should not be used over the long term by underweight people today.
Remember, starvation mode relates not to metabolism stopping completely, but the "adaptive biochemical and physiological changes that reduce metabolism in response to a lack of food." Anyone who eats at a deficit to TDEE will lose weight over time. If you believe this is not the case for you, then you are either incorrectly measuring your intake or incorrectly calculating your TDEE. Any other explanation defies science. The magnitude and speed of the metabolic slowdown will depend on the individual.
Again from Wikipedia:
"The magnitude and composition of the starvation response (i.e. metabolic adaptation) was estimated in a study of 8 individuals living in isolation in Biosphere 2 for two years. During their isolation, they gradually lost an average of 15% (range: 9–24%) of their body weight due to harsh conditions. On emerging from isolation, the eight isolated individuals were compared with a 152-person control group that initially had had similar physical characteristics. On average, the starvation response of the individuals after isolation was a 180 kcal reduction in daily total energy expenditure. 60 kcal of the starvation response was explained by a reduction in fat-free mass and fat mass. An additional 65 kcal was explained by a reduction in fidgeting, and the remaining 55 kcal was statistically insignificant."
My only goal is to help more MFP members understand what "starvation mode" actually means as I believe it is among the most misunderstood terms in the forums. I am not advocating that anyone start a very low calorie diet. Just because "starvation mode" is misunderstood as applied to many people, does not mean I think a very low calorie diet is the best method for anyone. Each individual should make his/her own diet decisions with consultation with his/her doctor.
Long term very low calorie diets are NOT appropriate for anyone within either the normal or underweight ranges of the BMI tables. Nor are they appropriate for anyone with medical conditions unless under the care of a medical doctor. However please do not automatically that everyone who consumes under a certain number of calories will automatically enter "starvation mode" and immediately suffer a dramatic drop in metabolism even if they started out as very obese (meaning they have an abundant supply of energy stores). According to the studies cited by Wikipedia metabolism does not stop or even slow down in an overly dramatic fashion for individuals who are severely obese (again this would be a major concern for those who are lean to begin with).
If you want to see more examples, read Table 1 (test of carbohydrate metabolism) in this study of a 382 day fast of an otherwise healthy 27 year old morbidly obese male under medical supervision:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2495396/pdf/postmedj00315-0056.pdf
The good news is that better understanding can help you protect lean muscle mass as you diet. If you are already lean to begin with, huge calorie deficits are more likely to cause muscle loss.
For anyone who wants to lose weight, according to Wikipedia:
"Resistance training (such as weight lifting) can also prevent the loss of muscle mass while a person is energy-restricted."
For those of you that hope to learn more about the true definition of "starvation mode", I hope this post and citations will help clear up some common misunderstandings.
I am not promoting any diet or particular intake level. The reason for this post is to encourage MFP members to learn more about the science behind "starvation mode". For those of you that like science I suggest reading some scientific studies on the topic. Wikipedia contains a lot of helpful citations:
http://en.wikipedia.org/wiki/Starvation_response
From Wikipedia:
"Starvation response in animals is a set of adaptive biochemical and physiological changes that reduce metabolism in response to a lack of food."
This basically means that after a certain point metabolism can slow down. Metabolism never stops as long as we are alive. The relevant question is how much metabolism slows.
From Wikipedia:
"Starvation mode is a state in which the body is responding to prolonged periods of low energy intake levels. During short periods of energy abstinence, the human body will burn primarily free fatty acids from body fat stores. After prolonged periods of starvation the body has depleted its body fat and begins to burn lean tissue and muscle as a fuel source."
Naturally, a morbidly obese person has an abundant supply of fat stores to begin with and can go a much longer period of time before burning significant lean muscle tissue for fuel (the same reason why a fat bear can hibernate for a much longer period than a bear who was lean before winter began). For this reason, scientific studies of long term very low calorie diets are ONLY conducted on overweight individuals. If someone is very lean to begin with they are at a much greater risk of losing lean muscle mass while eating under TDEE. For centuries before food became so easily available we had periods of feast and famine. During the famine period most people ate very low calorie diets. Some of them died. Who was more likely to survive? Naturally the people who were very overweight before the famine began (unlike today, for much of history it was the rich population who was obese, often by choice for this very reason). People who were very lean before the famine began often did not do well. This is the same reason very low calorie diets should not be used over the long term by underweight people today.
Remember, starvation mode relates not to metabolism stopping completely, but the "adaptive biochemical and physiological changes that reduce metabolism in response to a lack of food." Anyone who eats at a deficit to TDEE will lose weight over time. If you believe this is not the case for you, then you are either incorrectly measuring your intake or incorrectly calculating your TDEE. Any other explanation defies science. The magnitude and speed of the metabolic slowdown will depend on the individual.
Again from Wikipedia:
"The magnitude and composition of the starvation response (i.e. metabolic adaptation) was estimated in a study of 8 individuals living in isolation in Biosphere 2 for two years. During their isolation, they gradually lost an average of 15% (range: 9–24%) of their body weight due to harsh conditions. On emerging from isolation, the eight isolated individuals were compared with a 152-person control group that initially had had similar physical characteristics. On average, the starvation response of the individuals after isolation was a 180 kcal reduction in daily total energy expenditure. 60 kcal of the starvation response was explained by a reduction in fat-free mass and fat mass. An additional 65 kcal was explained by a reduction in fidgeting, and the remaining 55 kcal was statistically insignificant."
My only goal is to help more MFP members understand what "starvation mode" actually means as I believe it is among the most misunderstood terms in the forums. I am not advocating that anyone start a very low calorie diet. Just because "starvation mode" is misunderstood as applied to many people, does not mean I think a very low calorie diet is the best method for anyone. Each individual should make his/her own diet decisions with consultation with his/her doctor.
Long term very low calorie diets are NOT appropriate for anyone within either the normal or underweight ranges of the BMI tables. Nor are they appropriate for anyone with medical conditions unless under the care of a medical doctor. However please do not automatically that everyone who consumes under a certain number of calories will automatically enter "starvation mode" and immediately suffer a dramatic drop in metabolism even if they started out as very obese (meaning they have an abundant supply of energy stores). According to the studies cited by Wikipedia metabolism does not stop or even slow down in an overly dramatic fashion for individuals who are severely obese (again this would be a major concern for those who are lean to begin with).
If you want to see more examples, read Table 1 (test of carbohydrate metabolism) in this study of a 382 day fast of an otherwise healthy 27 year old morbidly obese male under medical supervision:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2495396/pdf/postmedj00315-0056.pdf
The good news is that better understanding can help you protect lean muscle mass as you diet. If you are already lean to begin with, huge calorie deficits are more likely to cause muscle loss.
For anyone who wants to lose weight, according to Wikipedia:
"Resistance training (such as weight lifting) can also prevent the loss of muscle mass while a person is energy-restricted."
For those of you that hope to learn more about the true definition of "starvation mode", I hope this post and citations will help clear up some common misunderstandings.
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Replies
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Nice post. There are also tons of other studies out there on the effects of diet on BMR at varying levels of weight, calorie restriction and lengths of time. I have posted a ton of them so there are quite a few in my post history. Additional information can be found by going to scholar.google.com and typing in whatever you want to research. It will pull up some books and articles but mostly peer reviewed research and journal articles some free and some not free.
Research does not really support what most people post on these boards.0 -
Thank you. Very valuable information!0
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Great post!!0
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never use wikipedia as a source.0
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I am not saying that any of this information is incorrect BUT Wikipedia is the least reliable source on the web. When I was in college we were not allowed to use it as a source ever. The site allows you to change any information without verification. I would find a different source. The Mayo Clinic has great information.0
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People will always believe that your body goes into starvation if you don't eat every two hours thanks to folks like Jillian Michaels. I hope some of those people stop by to read this post.0
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The trick to using wikipedia as a source is to use its sources.
Also is this new thang of discounting the source rather than the statements this generation's ad hominem?0 -
never use wikipedia as a source.
I was thinking/going to say the same thing...
However, Starvation Mode is one of the most used terms on the threads and people really have no clue as to what they are saying. essentially, it boils down to the fact that you have to eat nothing for 72 hours to go into true starvation mode where you would start turning to muscle for energy; even at the 72 hour mark the effects of starvation mode are minimal. I would suggest anyone interested in finding the actual studies go to www.leangains.com...it is laid out pretty well there.0 -
Holly cow. He lost 302 lbs (482 to 180) on a medically supervised fast for over a year. Can you imagine not eating anything for that long? I wonder what it was like to learn to eat again.0
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Wikipedia can be a great source of information if you use it as a place to find sources just as he has done. Read the information and the sources before discounting someone's very well written and well forced post just because t mention Wikipedia.
Great post!0 -
Holly cow. He lost 302 lbs (482 to 180) on a medically supervised fast for over a year. Can you imagine not eating anything for that long? I wonder what it was like to learn to eat again.
It undoubtedly felt wonderful to be 302 pounds lighter. He also probably could not have gotten down to 180 on a more gradual method.0 -
never use wikipedia as a source.
Wikipedia has very accurate information. Your post is void..0 -
Good post.0
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Wikipedia has been proven to be just as reliable as any other encyclopedia. I know it's counter intuitive because the information is editable by anyone, but the fact remains that misinformation doesn't last long on Wikipedia because it is quickly edited out.
Several studies have been done to assess the reliability of Wikipedia. A notable early study in the journal Nature said that Wikipedia scientific articles came as close to the level of accuracy as Encyclopedia Britannica and had a similar rate of serious errors. A study conducted by IBM found that "vandalism is usually repaired extremely quickly—so quickly that most users will never see its effects"
The reason it's banned from use for school research papers has nothing to do with it's reliability, and everything to do with how easy it would be to write a paper using only Wikipedia as a source. Your teachers want you to have to work harder than that.0 -
Yep, so good that most reputable sources won't touch it. So good that most college professors don't allow it. So good the the company its self admits it has problems with erroneous information. So good that some "definitions" end up locked because of bad information.never use wikipedia as a source.
Wikipedia has very accurate information. Your post is void..
Wikipedia is garbage.0 -
I am not promoting any diet or particular intake level. The reason for this post is to encourage MFP members to learn more about the science behind "starvation mode". For those of you that like science I suggest reading some scientific studies on the topic. Wikipedia contains a lot of helpful citations:
I am sorry that many of you do not like Wikipedia. I mention the page because it is a source of well organized information that happens to mention multiple sources on the topic in question. Thank you for those that took the time to address the content of my post instead of debating whether or not Wikipedia was a reliable source. Feel free to tell me which source cited by Wikipedia you have a specific issue with. I have no interest in defending Wikipedia in general.0 -
Great post, regardless of cited sources. If people want to source data, they can click the reference links ;-)~0
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never use wikipedia as a source.
I was thinking/going to say the same thing...
However, Starvation Mode is one of the most used terms on the threads and people really have no clue as to what they are saying. essentially, it boils down to the fact that you have to eat nothing for 72 hours to go into true starvation mode where you would start turning to muscle for energy; even at the 72 hour mark the effects of starvation mode are minimal. I would suggest anyone interested in finding the actual studies go to www.leangains.com...it is laid out pretty well there.
Great post! I agree that the author of that website does a good job citing actual science. While 72 hours is an estimate (see citations below) I think the clear point is that that fasting for short periods will not trigger "starvation mode" People like myself who often fast for 24 hour periods, but still hit their weekly calorie targets are at no risk of harming their metabolism.
http://www.leangains.com/2010/10/top-ten-fasting-myths-debunked.html
http://www.ncbi.nlm.nih.gov/pubmed/3661473
In fact some studies have shown that short term fasting can actually cause a temporary boost to metabolism
http://www.ncbi.nlm.nih.gov/pubmed/2405717
http://www.ncbi.nlm.nih.gov/pubmed/108372920 -
Ah, now I remember why you're on my friends list :flowerforyou:
Quality post, bro.0 -
Yep, so good that most reputable sources won't touch it. So good that most college professors don't allow it. So good the the company its self admits it has problems with erroneous information. So good that some "definitions" end up locked because of bad information.never use wikipedia as a source.
Wikipedia has very accurate information. Your post is void..
Wikipedia is garbage.
It's not an all or nothing thing. If the sources are sound and the information is presented accurately, it's good. The problem is it doesn't stop some knucklehead from posting some crap info for fun.
That's why you need discernment when evaluating information and not blindly accepting things.0 -
never use wikipedia as a source.
Yep, sorry, OP, but you lost me at "Wikipedia" 0 -
never use wikipedia as a source.
^^^THIS!
I tell my students to avoid wikipedia as a source for any and all research projects they are required to do. ANYONE can go on there and edit ANYTHING they want.0 -
Excellent post!0
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Wikipedia has been proven to be just as reliable as any other encyclopedia. I know it's counter intuitive because the information is editable by anyone, but the fact remains that misinformation doesn't last long on Wikipedia because it is quickly edited out.
Several studies have been done to assess the reliability of Wikipedia. A notable early study in the journal Nature said that Wikipedia scientific articles came as close to the level of accuracy as Encyclopedia Britannica and had a similar rate of serious errors. A study conducted by IBM found that "vandalism is usually repaired extremely quickly—so quickly that most users will never see its effects"
The reason it's banned from use for school research papers has nothing to do with it's reliability, and everything to do with how easy it would be to write a paper using only Wikipedia as a source. Your teachers want you to have to work harder than that.
I ban it because it is an uncertifiable resource. I tell my students (who are in middle school, btw) that I only want them using websites that contain a .edu or .org suffix on them, as the rest of them (.com or .net) are unreliable and likely can be disputed as to their origin of authenticity and varified facts. I prefer they go directly to the websites that are second sources or primary sources.0 -
Did you guys even check out the sources?
Not linked to blogs or news articles but scientific studies. Haven't checked them out extensively but kind of arrogant to dismiss information out of hand because it must be wrong because it's wikipedia.
I'm glad I had a college english professor make us choose a topic on wikipedia and update it.0 -
The conclusion of this thread is that if you read Wikipedia then you will go into Starvation mode.0
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Did you guys even check out the sources?
Not linked to blogs or news articles but scientific studies. Haven't checked them out extensively but kind of arrogant to dismiss information out of hand because it must be wrong because it's wikipedia.
I'm glad I had a college english professor make us choose a topic on wikipedia and update it.
I'd rather they go STRAIGHT to the sources, and not start at Wikipedia. If taught properly, they would know what the .edu and the .orgs have to offer. What's the point in starting with wikipedia, if only to get the sources?0 -
Wikipedia has been proven to be just as reliable as any other encyclopedia. I know it's counter intuitive because the information is editable by anyone, but the fact remains that misinformation doesn't last long on Wikipedia because it is quickly edited out.
Several studies have been done to assess the reliability of Wikipedia. A notable early study in the journal Nature said that Wikipedia scientific articles came as close to the level of accuracy as Encyclopedia Britannica and had a similar rate of serious errors. A study conducted by IBM found that "vandalism is usually repaired extremely quickly—so quickly that most users will never see its effects"
The reason it's banned from use for school research papers has nothing to do with it's reliability, and everything to do with how easy it would be to write a paper using only Wikipedia as a source. Your teachers want you to have to work harder than that.
I ban it because it is an uncertifiable resource. I tell my students (who are in middle school, btw) that I only want them using websites that contain a .edu or .org suffix on them, as the rest of them (.com or .net) are unreliable and likely can be disputed as to their origin of authenticity and varified facts. I prefer they go directly to the websites that are second sources or primary sources.
http://en.wikipedia.org/wiki/.org
Wikipedia says anyone can have a .org website, including craigslist.org. Its not reliable information though so I don't know.
And if that is how you like to teach your students to learn I don't really care and I'm not saying you are right or wrong for doing so (no offense). The point is several people dismissed the OP who appears to be trying to post pertinent information regarding a topic that is largely misunderstood and misrepresented on MFP because they saw wikipedia.0 -
I wouldn't recommend Wickipedia as a source of information. The American Medical Association has a lot of reliable and scientifically based sources of information. I have college professors who tell me never to use wikipedia as a source of information. Just saying
Lisa0
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