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TOPIC: Starvation Mode Myths and Science

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February 12, 2010 9:51 AM
So sick of reading responses of people regarding diet and weight loss with everyone throwing around purported "facts" about starvation mode. So, here is a little research on the topic. Feel free to chime in with other studies, but lets keep it based on actual research, not personal anecdotes and not "my trainer says."

Starvation mode does not happen overnight or even in just a few days! Calories in, calories out. Simple, right? Short term, yes, it’s simple, long term, not so much. Let’s add some real science to the discussion:

First, a definition. Starvation mode does not mean going without food. It means that you cut your caloric intake to less than what the body would normally burn in the course of a day. I have seen so many posts where people offer advice and tell people they need to eat more to lose weight because they are starving their bodies. The idea postulated is that eating too few calories will reduce a person’s metabolism to such an extent that the person will gain weight instead of losing.

Now, a look at one of the classic scientific studies on starvation. Probably the most famous study done was conducted after WWII by researchers at the University of Minnesota. Starvation was widespread throughout Europe during the war and scientists were trying to figure out how to re-feed people suffering from starvation and determine the long-term effects. (Remember, tens of thousands of people died after liberation from concentration camps not only from disease but from the reintroduction of food that their bodies were no longer capable of digesting.) Scientists recruited 36 young healthy men to participate in a yearlong study divided into several phases: a 12-week normal control period, a 24-week starvation phase where calories were so dramatically reduced that participants lost approximately 25% of body weight; and, finally, a recovery phase to renourish participants. Results of the study were published in the two-volume, Biology of Human Starvation (Minneapolis: University of Minneapolis, 1950). See more information here: http://en.wikipedia.org/wiki/Minnesota_Starvation_Experiment.

So, what did the results of the study find? First, all participants lost weight. Starvation mode does not result in your body hanging onto extra fat or calories in an effort to “preserve” your body. But, it’s more complicated than just losing weight. All of the participants also experienced a drop in their metabolic rates – approximately 40% below baseline. Now, you will see many posters here that will argue that you will start losing muscle and not fat within a few days of going into so-called “starvation mode.” Yet, the research shows that participants lost both. In fact, at no point did they stop losing fat until they hit a rate of approximately 5% body fat near the end of the study.

Lyle McDonald explains it this way:

In general, it's true that metabolic rate tends to drop more with more excessive caloric deficits… But here's the thing: in no study I've ever seen has the drop in metabolic rate been sufficient to completely offset the caloric deficit. That is, say that cutting your calories by 50% per day leads to a reduction in the metabolic rate of 10%. Starvation mode you say. Well, yes. But you still have a 40% daily deficit.

But, keep in mind that apart from weight loss, semi-starvation has other not-so-cool effects on your mind and body. The other physical effects from the Minnesota study on semi-starvation included a significant drop in physical endurance, reduction in strength of about 10%, and sluggish reflexes. Those that were the most fit initially showed the greatest deterioration. In addition, heart volume shrank about 20%, pulses slowed and their body temperatures dropped. Concentration and judgment became impaired. Sexual function was reduced and all lost interest in sex. They had every physical indication of accelerated aging. But keep in mind, this was a year-long study, not something that happened in a just a few days or two weeks of eating restricted calories.

The more dramatic effects of semi-starvation from the Minnesota study were psychological, similar to what can be observed in anorexic patients. The men became nervous, anxious, apathetic, withdrawn, impatient, self-critical, emotional and depressed. A few even mutilated themselves, one chopping off three fingers in stress. They became obsessed with food, thinking, talking and reading about it constantly; developed weird eating rituals; hoarding, etc.

Now, let’s look at another aspect. The folks at Cambridge University in England did a study to determine the different effects starvation had on lean people versus obese people. The study can be found here: http://www.unu.edu/unupress/food2/UID07E/uid0 7e11.htm. Let’s just cut to the chase with this study.

Does starvation mode slow down the metabolism? No and Yes.

In the first 2 days of starvation, there is a small absolute increase in basic metabolic rate relative to values obtained from overnight fasting. Overnight fasting is what every one of us does during our sleeping hours. So it is not true that going below recommended calories for one day is going to slow down your metabolism -- quite the contrary, it may speed it up just a little. Of course, this is just limited to the first few days. After that, studies in fact support that “starvation mode” slows down metabolism.

Does Starvation mode cause our bodies to catabilize (devour our muscles and other lean mass)? Yes and No.

Lean individuals lost great amounts of fat-free, lean tissue during starvation, but obese individuals lost much more fat tissue. The loss of lean mass is not as critical to the obese person simply because an obese person has more lean mass than a person of the same age and height but normal weight. Here we get to a basic idea that makes sense – fat storage – the same way animals build up bulk to rely on during the winter, obese people have fat stores they can use (to a limited extent) in times of need. This means that the effects of a semi-starvation diet upon a normal weight individual are of course much more devastating than the effects on someone who is obese.

Finally, some conclusions. Does all this mean I should reduce my caloric intake below the minimum recommended as an effective way to lose weight? If you think the answer is yes, then you haven’t carefully read everything here, so I will spell it out:

Let’s start by clearing up that major myth I see repeated over and over again in the forums: that a single day or even a few days of extreme caloric restrictions forces your body into starvation mode, significantly reducing your metabolism and causing you to lose muscles. Not true. You may, in fact, lose weight in the short term. Your body does not go into starvation mode after a few days of extreme calorie restricted eating.

However, let’s look again at the Minnesota study for further compelling evidence why semi-starvation is not a good idea for long-term weight loss. In the latter half of the Minnesota Starvation Study the men were allowed to eat ad libitum again. Researchers found they had insatiable appetites, yet never felt full, these effects continued for months afterwards. Semi-starvation diets don’t work long-term for this simple reason – under ordinary pressures, when eating resumes, people put the weight back on and oftentimes, gain more.

And let’s not forget the other physical and psychological effects mentioned earlier. Any of those sound appealing to you? Reduced concentration or sexual function anyone? The Cambridge study also looked at several deaths from people who undertook extreme starvation diets, particularly those that did not create a good nutritional balance in the calories that were consumed.

Bottom line, you should do adequate research and dietary analysis to ensure you are getting the best nutrition you can for your calories.
February 12, 2010 9:55 AM
Thank you!! I agree.
  226682
February 12, 2010 10:03 AM
Great post. Thanks for taking the time to research this and post it.
  232101
February 12, 2010 10:04 AM
Excellent post. I'm adding a link to this thread in my bio for future reference.
  633569
February 12, 2010 10:05 AM
so how much below BMR for caloric intake is semi starvation or starvation starting at...
Thanks
  407025
February 12, 2010 10:05 AM
BUMP!

Great post!

drinker
February 12, 2010 10:10 AM
i know i could look up these studies myself, but i'm hoping to get an easier answer from you! bigsmile what amount of calories were being consumed on the restricted calorie portion of the study? i feel completely satisfied on 1200 calories, so i'm assuming that the studies used far fewer than that. but it would be good to know.
February 12, 2010 10:11 AM
And the CHURCH SAYS AMEN!!!
If I am under 100 calories from my goal on any given day, the first thing some people fling out is "your starving yourself" VERY ANNOYING!
Thanks for the post.
  216688
February 12, 2010 10:16 AM
Any information on how this relates to the reported "Life Extending" benefits of an ultra low calorie diet?
  637572
February 12, 2010 10:22 AM
QUOTE:


However, let’s look again at the Minnesota study for further compelling evidence why semi-starvation is not a good idea for long-term weight loss. In the latter half of the Minnesota Starvation Study the men were allowed to eat ad libitum again. Researchers found they had insatiable appetites, yet never felt full, these effects continued for months afterwards. Semi-starvation diets don’t work long-term for this simple reason – under ordinary pressures, when eating resumes, people put the weight back on and oftentimes, gain more.



Hmmm... can we say "Yo-yo dieting"? THANK YOU for this VERY informative post!!! flowerforyou
  432270
February 12, 2010 10:27 AM
Great Post and thank you for doing the research!flowerforyou

Laura
  199400
February 12, 2010 10:29 AM
This is what I heard...blah blah blah blah blah. After eating only once a day for decades, I experienced first hand the effects of not taking in adequate calories to sustain a healthy body. I lost muscle, my energy was ridiculously low and my immune system sucked. That was my reality.

Studies are great, but ever notice how something is the gospel of the day based on research and science and a few months, years, decades or centuries later, newer studies prove something else? i.e. Red wine, coffee, newtonian physics, quantum physics, etc.

Perhaps consensus reality is what determines what is myth and what is science. Just a thought. ;P
  234020
February 12, 2010 10:30 AM
Very helpful information - Thanks for posting.
Edited by m2kjenn On February 12, 2010 10:31 AM
  240419
February 12, 2010 10:35 AM
QUOTE:

i know i could look up these studies myself, but i'm hoping to get an easier answer from you! bigsmile what amount of calories were being consumed on the restricted calorie portion of the study? i feel completely satisfied on 1200 calories, so i'm assuming that the studies used far fewer than that. but it would be good to know.


actually the MN study participants received approx. 1,560 cal per day on the restricted-diet weeks. But, keep in mind the baseline diet was approx 3,200 calories, and these were all active, healthy, young men. During the semi-starvation period, they were required to complete daily work tasks and walk 22 miles per week, so they were forced to stay active.
February 12, 2010 10:38 AM
QUOTE:

This is what I heard...blah blah blah blah blah. After eating only once a day for decades, I experienced first hand the effects of not taking in adequate calories to sustain a healthy body. I lost muscle, my energy was ridiculously low and my immune system sucked. That was my reality.

Studies are great, but ever notice how something is the gospel of the day based on research and science and a few months, years, decades or centuries later, newer studies prove something else? i.e. Red wine, coffee, newtonian physics, quantum physics, etc.

Perhaps consensus reality is what determines what is myth and what is science. Just a thought. ;P


We are in fact reaching the same conclusions! Extreme caloric restrictions are not healthy long term. See the later part where I mention the loss of muscle, other physical and psychological side-effects. What I am getting at is it is crazy for people to tell others they are in starvation mode after just a few days of restrictions. It doesn't mean you won't lose weight by restricting yourself, but, bottom line, is long-term it produces harmful effects.
February 12, 2010 10:54 AM
thanks for the post, very informative!
February 12, 2010 10:56 AM
superschupp

CR is a lifestyle and you have to find and diligently monitor you proper caloric intake. It usually is around 30% not starvation level or 50%. It is usually high protein and is only for people who have past the child bearing age. The most poignant fact is you still have the psychological disturbances associated with starvation.
Edited by ivykivy On February 12, 2010 10:57 AM
February 12, 2010 11:05 AM
That might be great and scientific and all that. . . . But, if you CAN eat a "normal" amount of calories and lose weight, why wouldn't you want to do that?
Aren't there going to be some metabolic repercussions when you restrict your calories to a ridiculously low amount, and then STOP doing that?
I'm reminded of the low carb diet craze. Yeah, it works, but the minute you start eating normal, healthy carbs again, it stops working.
I'm in this for the long haul. I eat my target calories, I eat my exercise calories. When I lose weight, I check in, change my settings and my calorie target is lowered. And I still lose weight.
  119882
February 12, 2010 11:10 AM
Oh, and I agree that the whole one or two days of eating well below your caloric target does not induce "starvation mode". Kinda silly.

Almost as silly as "muscle weighs more than fat". A pound of muscle and a pound of fat both weigh. . . .a pound!
  119882
February 12, 2010 11:12 AM
I agree and disagree with most of the things on this post.

I agree with much of the science, although ALL of it is conjecture, but that's how science is, because the human body is so complex, taking the results from one test group and applying it to another is never going to give 100% accurate results. That's neither here nor there though, as it's kind of a nit picky point (sorry).

Anyway

What I disagree with, is the way it was brought up. While I agree that too many people on here blithely net shout "YOU'RE NOT EATING ENOUGH", that doesn't mean the opposite is true. In many cases my first thought after reading a post is the same, although I always ask for a person's numbers before I even make an educated guess at what the problem is. Starvation mode is real, and it's rampant here. Mainly because very few people, when they start out in weight loss, understand what a correct goal should be. It's utter frustration for me, I see it so much. People looking to lose 10 or 20 lbs should NOT be trying to lose 2 lbs a week, their body just can't support it, you need a certain amount of surface area adipose fat, to be able to pull that many calories from said fat. It goes to the root of the problem, which is impatience. People like the convenience of MFP and choose to see the ease of setup as a shortcut, not realizing that just because you can quickly throw in some goals, doesn't make those goals the right ones for you. Heck, I can set a goal of being an Olympic Luger, doesn't mean it's a goal I can realistically meet, and trying could cause me more harm than good (in more ways than one).

I have tons more opinions on this topic, most of which were thoroughly researched, but I'm not at home where all my research is, and truthfully, I don't have the energy for another starvation mode debate. I read through that army study a long time ago, it's posted on ajcn.org if you want to read the actual study.
February 12, 2010 11:18 AM
first of all a pound of fat is not the same SIZE as a pound of muscle, it's bigger! Therefore if you lose fat and gain muscle you will appear smaller even if no weight difference has occured. Second, I think most people who are posting are trying to warn people what could potentially happen to them if they continue to take in too few calories. Besides a obese person can be malnourished, as it is not the same as not getting enough calories. If someone tries to lose weight and takes in too few calories, there body may use excess fat or muscle as energy, but they could also not get enought nutrients from their food. Either way not taking in enough calories is unhealthy and those people should be talking to their doctors not people on a fitness website!
  574206
February 12, 2010 11:21 AM
Not to mention starvation/malnutrition not only occurs when calories are restricted they can occur when calories are abundant because you do not have proper nutrients. So if you're eating 1200 calories, exercising 2 hours and eating snack packs and non-fat this and that on very little protein, your are looking for trouble in the long term.

Honestly if most people actually took the time to read the study and after study they would not be so gung ho to eat at starvation level. And like Boss said the study was done on a group of fit men not unhealthy men or women. Add starvation issues on top of PMS and you have a straight messlaugh

http://junkfoodscience.blogspot.com/2008/02/how-weve-came-to-believe-that.html

http://jn.nutrition.org/cgi/content/abstract/135/6/1347?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=minnesota+experiment&searchid=1&FIRSTINDEX=0&sortspec=relevance&resourcetype=HWCIT
February 12, 2010 12:12 PM
Let's be honest though. There are Starvation Mode Nazi's who would have you beleive that missing your mid-morning snack would cause you to spiral into starvation mode. I think a lot of that is proliferated by people trying to sell something. I think that's what Fit4Europe was getting at. And I agree.
February 12, 2010 12:18 PM
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

What he said!
February 12, 2010 12:23 PM
I agree it's a shame so many folks here are in the dark about starvation mode and I thank you for posting the research. There's so much good and factual information on this site already about starvation mode, however, don't be disappointed if this post falls on deaf ears (It's too lengthy for a vast majority of MFPers to take the time to read anyway frown).

But I have to say I honestly think it's healthier for people (to be derogatory and crass, "sheeple") to believe that they're going to go into starvation mode with a few days of undereating than it is for them to believe they have to eat as little as possible to lose weight. ohwell
Edited by LittleSpy On February 12, 2010 12:26 PM
  270768

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