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Weight Loss
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The Truth about "Starvation Mode"

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Since brokentink's thread received such a strong reaction, I thought I'd research this subject to see what the research studies show about starvation mode, what gets you into it, and what the short-term and long-term effects are.

First, what is starvation mode?  I found this direct answer on --

A starvation diet does not mean the absence of food. It means cutting the total caloric intake to less than 50% of what the body requires.

Using myself as an example, my current weight is 183 lbs. and my bmr is 1450.  So, I would have to cut my calories to below 725 per day.  However, if I were at my goal weight of 109 lbs., my bmr would be 1129, and so I would have to cut my calories to below 565 calories.

Many fear that going into starvation mode will drastically reduce their metabolic rate and cause them to hoard calories and gain weight instead of losing.

This is not borne out by the infamous Minnesota Semistarvation Study (1950), 36 young, healthy, psychologically normal men while restricting their caloric intake for 6 months.  Their calories were restricted in various phases, but the least amount of calories they were allowed was 50% of the "normal" maintenance calories.  Notice, this was dubbed a "semi" starvation diet.

Yes, their metabolic rates were significantly lowered -- to something like 40% below baseline.  Yet at no point did the men stop losing fat until they hit 5% body fat at 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 (and this is true whether the effect is from eating less or exercising more); as well, people vary in how hard or fast their bodies shut down. Women's bodies tend to shut down harder and faster.

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.

And then he follows with the note about the Minnesota men still continuing to lose fat even thugh their metabolic rates had dropped to 40% below baseline.  He says, further, that no study that he's aware of where people were put on strictly controlled diets failed to acknowledge weight or fat loss. lyle.htm

Did the Minnesota men suffer negative consequences from the experience.  They most certainly did, and, interestingly, many of the same consequences that anorexics experience.  You can read all about the various negative consequences at this site and the implications for EDs. age=EffectsOfSemiStarvation

Another starvation study was done in England, at Cambridge University, to determine the different effects starvation had on lean people versus obese people.  It's findings are quite relevant to our discussion.  The entire study is found at 7e11.htm.

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

In the first 2 days of starvation, there is a small absolute increase in BMR 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. 

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.  Obese individuals have a mechanism that conserves lean mass and burns fat instead.  In the study, an example of a lean subject studied after death from starvation: it can be deduced that loss of body fat accounted for 28-36% of the weight loss and fat-free mass 64-72%. In obese individuals, the proportion of energy derived from protein (Pcal%) is only 6% compared to 21% in the lean individual. More than half the weight loss in the obese is fat, whereas most of the weight loss in the lean individual is fat-free mass.

And the loss of lean mass is not as critical to the obese person as to the lean person simply because an obese person has more lean mass than a person of the same age and height but normal weight. 

Grossly obese individuals (FORBES, 1987; JAMES et al., 1978) may have over 30% more fat-free mass than lean individuals of the same height. In the example shown in Figure 3, the obese individual weighting 140 kg has a fat-free mass that is 29% greater than the 70 kg man. Obese individuals appear to have more muscle and bone than lean individuals, and these help support and move the excess body weight. Obese subjects have large vascular volumes and larger hearts, which are necessary to pump more blood around larger bodies, especially during weight-bearing activities. Obese individuals may also have visceromegaly (NAEYE and ROODE, 1970).

But when you think about it, doesn't that make fat storage sense?  Why would our Maker create us with the ability to store fat if it couldn't sustain us and preserve our lean mass in cases of extreme want?

So the effects of a starvation diet upon a normal weight teen would be substantially more devastating than to me, a morbidly obese person. 

Now, if the above gives anyone "permission" to undertake a starvation diet, I recommend remedial reading classes.

My opinion is, you should not go below your goal weight maintenance calories to lose weight, and you should do adequate research and dietary analysis to ensure you are getting the best nutrition you can for your calories.

If reducing your calorie intake to goal weight maintenance creates greater than 1000 calorie a day deficit, then I strongly suggest that you do a value half-way until you have lost some of your weight.

Now some advice for those unfortunate individuals who are suffering from EDs or who have foolishly ventured into starvation dieting.  This comes from .htm

Hi, I`m a RD. Have a client that is in the starvation mode. Know your are supposed to not change amount of calories consumed but help them to eat differently. Not sure what this means. Not had a client like this in past. Also, know it will take ~ 6 months for this client regain an appetite. Client states not hungry. I`m out in an area with not a lot of access to information. Hope you can help me to help them. God Bless
Thank you for your question. Many people think that starving themselves will lead to fast weight loss. A starvation diet does not mean the absence of food. It means cutting the total caloric intake to less than 50% of what the body requires. The body responds by using its own reserves to provide energy, and these reserves are not just the body`s extra fat. Initially, glycogen stores are broken down for energy. Glycogen is the storage form of carbohydrate in our body. There is little glycogen available so this energy source is depleted during the first hours of starvation. When glycogen is used, water is released which is noticed as a drop in weight on the scale. These labile stores are quickly replenished when feeding is resumed which is noticed by an increase in weight.

The individual`s initial weight when starting a starvation diet will dictate to what extent fat is lost. Those individuals who are not obese (Body Mass Index (BMI) < 30) will tend to lose their lean body mass more easily and quickly than those who are obese (BMI > 30). It is dangerous for these smaller individuals to go on a starvation diet because the lean mass that is lost may come from organs such as the heart. In the 1970`s there were several deaths resulting from starvation-type diets. Death is a rare side effect, though.

The more common problem resulting from starvation-type diets is the resultant weight regain. Weight is typically regained because there has not been a change in the lifestyle that led to the original weight gain. When the starvation diet is ended, the individual returns to the same old habits. The scale will indicate the weight regain, but it will not identify the composition of the added weight. When weight is regained, it is fat. When fat replaces the muscle mass that was lost during starvation, the metabolic rate (the number of calories needed to maintain the current weight) is decreased. The frustrated individual typically initiates another starvation-type diet only to continue this cycle.

To help an individual break this cycle, begin with a diet history, and help the client make some small changes. The goal should be 4 - 6 small meals/snacks that result in a balanced intake. Also get the patient started exercising. Weight training will be important for rebuilding the lost muscle mass. Increasing muscle mass and increasing aerobic exercise will help increase the appetite appropriately. Don`t forget to help the client identify a realistic weight loss goal. That goal should never exceed 10% of initial weight in a six-month period. After six months, the client should try to maintain the loss for a few months before considering further weight loss.

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Thank you thank you thank you! Good work....very helpful:)
Lots of information, thanks!

All I know,  is no one has ever told me you are not losing weight because your not eating enough.  I don't mean to be a heretic butt I have a feeling your majority of peple are eating too much if they aren't losing not not eating enough.  I can only speak for myself of course.   

Most diets I have been on, this time I choose a life style change, I only ate about 1400 calories.  I worked out every single day and I am 5'8" medium to large frame.  I lost weight every single time down to my goal.  So, perhaps I was in starvation mode but I still lost the weight.  Of course, I was starving alll the time!!!  Perhaps,  that is what starvation mode was for me! LOL

  I refuse to do that ever again and am more than happy to eat the right amount of calories for my active life style.  I do think this is an over blown phenomenon though as I said more people are eating too much and not excersing enough.  That is my humble opinion anyway.  It is an interesting philosophy and subject.

  Some days we are more hungry than others and some of us are trying to heal our food disorders.  So, I say if you are full you should stop eating.  I am trying to listen to my physical hunger not emotional or even calorie intake.  I think it is different for everyone.  Each one of us has to bogey to our own drum.  Thanks 
Manewell - great job! I actually also went googling after reading that thread, and read many of the same articles, but you explain it better than I could! 

Digdig - from what I understand, when you start eating normally again, the weight comes on faster than ever, and your body composition is *worse* than before you dieted. Here's why (and manewell can correct me if I've got this wrong):

Glycogen is the brain's only energy source. It can't get glycogen from stored fat. If there's insufficient glycogen circulating in your system due to restricted calorie intake, then the body has no choice but to break down the muscles for glycogen to feed your brain.

When you've reached your goal, you have lost not only fat but a certain percentage of muscle (lean mass). If you are severely restricting your calories, there is no way to avoid this. The leaner you are to begin with, the higher the percentage of muscle you lose.

When you start to refeed (i.e., increase your calories to maintenance level) the weight comes on as pure fat, not muscle. Therefore your period of restricted dieting  has changed your body composition. For example maybe before your diet, your body fat percentage was 28%. After your diet when the weight comes back on, your body fat percentage will be higher than that.

This is why weight training is so important. Without it, if you constantly cycle from one restricted diet to another, you will simply get fatter and fatter - regardless of the weight number on the scale - as you lose more and more muscle and never regain it.
I have to second the fact that serious starvation makes you fatter in the end.  When I was a teen I ate less than 500 calories for a very long time to lose weight.  Once I had no control over my food I gained weight very very quickly, like ilisa said, in nearly a month.  It really is a waste of time.  Sure I was skinny (and sickly) looking for a while but once I went back to normal calories my body stored it all as fat.  By the time I was back to my high weight at 17 I was 165 and 36% body fat.  I am 180 now and 10 years later at 31.5% so you can imagine the difference on a smaller body being MORE % fat. 

So my question is WHY then do some stop losing weigh ALL TOGETHER above the 50% mark?  Like I said before my sedentary number is 1881 and the bmr is even lower, in the 1600, so my 50% thing would be above 800-900 calories a day to still lose without ill effects right?  But at 1200-1300 I wasnt losing!  And I gave it over a month!!!  I swear, I have the freaking body from hell, I must have been an axe murderer in my last life and this is my punishment.
I don't quite understand this either.  According to CC, my maintenance should be 1900 calories.  At 1900 calories, I would gain 2-3 pounds/week.  No kidding.  At 1400 calories, I seem to be maintaining things.  And, below that I still lose nothing.  I don't get it. 
Is this net calories consumed without subtracting calories burned from exercise? If I am on 1200 calories a day but then burn 600 at the gym, am I not consuming enough calories?
Great research and a good OP. I don’t know why this is not pinned to the top (and the misleading info on eating multiple meals per day is).The truth is - weight loss is by nature - a catabolic process.   Many so-called experts refer to any catabolic state as "starvation".  This confusion is purposely caused to hype "my diet plan is better than their diet plan - so you must buy my book".  All any dieting is eating fewer calories than expended.   

I constantly see many people throw the "starvation mode" term out like it has instant negative ramifications toward healthy weight loss.  The other term used is the "starvation protection mechanism".    Granted, serious calorie deficits are very unhealthy and can cause long term medical problems – but it bothers me when I see people spouting wrong information about short or long periods of fasting.

This was some fascinating information - thanks so much for posting.

I was more intrigued by the psychological effects on the semistarvation subjects than I was by the metabolic effects.  In fact, reading about what these men underwent, it kind of brought tears to my eyes because I can relate with the uncontrolled eating after a long period of restricted eating.

 I personally am slightly concerned with my own intake - torn between the fear that I may be eating too little and risking a rebound gain later on, and the fear that if I eat much more than I do now, I'll go nuts and pig out every day, or the fear that if I eat the maintenance calories for my goal weight, that the weight loss will take so long that it's unbearable to do that.

I also can identify with the preoccupation with food these subjects felt.  I know that my posting here is part of such a preoccupation, and I do tend to savor my food more now.

I thought I was doing pretty good - I eat a LOT of fresh colorful vegetables and get at least 25% of calories from protein and consume a total of 1600-1800 per day.  I'm 6'2" and 193 lbs hoping to get to and maintain at 170.  I also take a multivitamin, go for walks in winter and bike rides in summer and do a daily routine with dumbells.  I felt like I was getting adequate nutrition, have plenty of energy and feel basically good, but the way my preoccupation with food and dieting mirrors the men in the study does concern me.  The idea that I might go nuts and start binging like they did is terrifying. 

One thing good is that I live in Japan, so I'm not being as constantly tempted by my old comfort foods as I would be in the states.

Metabolically, I don't feel like I'm in starvation mode because I have lost weight consistently on this intake (although the rate of loss has slowed in the last month) and have had adequate energy.  I'm not bothered that the rate of loss has slowed since I'm getting close to my goal weight.  Once I am at my goal weight, however, I'm a little apprehensive about adjusting to maintenance calories.  I feel like I will need to gradually up them while strictly monitoring my weight to see exactly what the maintenance count should be, because I don't entirely trust the site's calculators.  They say I should eat between 2200 and 2500 to maintain at 170, but I have this hunch that something around 2000 would be about right for me... 

I just read another article by a fitness guy (no dietician certifications noted) who was throwing around the starvation protection mechanism, he claimed if you don't eat for 3 hrs and 20 mins, you went into the SPM and your body canabalized all your muscle.

I think the thing that confuses many dieters, is the advise from body builders.  Body builders are trying to gain mass and lose fat at the same time.  They often use themselves as the test subject and base all their research on themselves.


You definitely have a good point about many bodybuilders using themselves as lab rats to find out what works for fat loss and muscle-building - just because someone has found a method that works for them doesn't mean it will work for everybody. I wish more people understood this. It's like everyone in my local gym goes to the biggest guy for advice, it doesn't make sense at all. What worked for that person will probably not work for someone else, especially a beginner.

I can't think of any reason that a starvation diet has benefits. Here is an excerpt from Tom Venuto of that sums up some of my thoughts about starvation mode diets:

"Ancel Key’s Minnesota starvation study is the classic work in this area, which dates back to 1950 and is still referenced to this day. In this study, there was a 40% decrease in metabolism due to 6 months of “semi-starvation” at 50% deficit.

Much or most of the decrease was due to loss of body mass, (which was much more pronounced because the subjects were not weight training), but not all of the metabolic decline could be explained simply by the loss of body weight, thus “metabolic adaptation” to starvation was proposed as the explanation for the difference.

Abdul Dulloo of the University of Geneva did a series of studies that revisited the 1300 pages of data that keys collected from this landmark study, which will not ever be repeated due to ethical considerations. (it’s not easy to do longitudinal studies that starve people, as you can imagine)

Here’s one of those follow up studies:

“Adaptive reduction in basal metabolic rate in response to food deprivation in humans: a role for feedback signals from fat stores. Dulloo, Jaquet 1998. American journal of clinical nutrition.


“It is well established from longitudinal studies of human starvation and semistarvation that weight loss is accompanied by a decrease in basal metabolicrate (BMR) greater than can be accounted for by the change in body weight or body composition”

“the survival value of such an energy-regulatory process that limits tissue depletion during food scarcity is obvious.”

Also, starvation mode is a series of intense food seeking behaviors and other psychological symptoms and if you do any research on the minnesota study and other more recent studies, you will find out that starvation mode as a spontaneous increase in food seeking behavior is very, very real.

Do you think sex is the most primal urge? Think again! Hunger is the most primal of all human urges and when starved, interest in everything else including reproduction, falls by the wayside until you have been re-fed.

There are even changes in the reproductive system linked to starvation mode: It makes total sense too because if you cannot feed yourself, how can you have offspring and feed them - when you starve and or when body fat drops to extremely low levels, testosterone decreases in men, and menstrual cycle stops in women."


(end excerpt) taken from l

When I read that, it confirms my thoughts that starvation diets are just a bad idea. It doesn't make sense to try and lose weight at the expense of your health in any situation. Normal weight ranges come as a by-product of natural, good health - NOT the opposite.

I'd love to continue the discussion if you have any other questions!

To your health and success,

John Sifferman NSCA-CPT

Fitness Professional

So since I did starve myself in college and weighed 105 lbs, (Which is small for my medium build).  Is that why I can't lose weight now?  I started at in Jan. 08' at  150 lbs and lost 10 lbs. on a 1200 calorie a day diet.  But now can't get under 140 lbs.  Everyone tells me to up my calories to 1400 to get over the plateau but maybe I have ruined my body and will have to eat less than 1200 in order to loss weight.


 Starvation diets damage the metabolism which can have lasting consequences.  Sometimes increasing your calories is what it takes to repair your metabolism to healthy levels.  Fat loss is achieved through four major things... proper nutrition, progressive strength training, progressive cardio (and usually a mixture of steady-state cardio and interval training throughout the week), and adequate recovery.  If these four things are in line correctly, fat loss will occur in a healthy environment.  If you're missing one (which can include not eating enough calories) your fat loss results will either be stalled or even prevented.  Make sense?

To your health and success,

John Sifferman NSCA-CPT

Fitness Professional

Are you sure it's half the BMR (basal metabolic rate) or the resting metabolic rate?

I haven't read up on it for a while so i could well be wrong, but from what i remember, you BMR is only the calories required to keep you alive, presuming you slept all day. If you are awake at all, even sedentary, you must multiply your BMR by 1.3 to get your RMR. This being a higher amount, could mean you might enter starvation mode earlier; at a higher calorie intake.

Starvation diets and calorie restrictive diets are two separate things.  One is dangerous and unhealthy, the other - a sensible way to lose EXCESS weight.
You bring up an important point - starvation mode is a serious concern when calories are restricted for a long period of time.  But Tom Venuto, leads you to believe the body enters starvation mode after a few hours of not eating.  But Venuto is focusing on individuals, like himself, with very little fat to catabolise during periods of fast.  With so little body fat, these individuals produce very little leptin and suffer from satiety problems.  Because of these extremely limited fat stores, their bodies are trying to adapt to this “starved condition” and they suffer from intensive food seeking behaviors. 
Tom Venuto does promote some sound dietary practices, but his reasoning is often misleading and his advice works better for an individual trying to become body builder "cut", than an individual trying to lose 30 or more pounds to reduce total body mass.   Again Venuto uses his own results - and Venuto's does not maintain a normally healthy percentage of body fat.  "Cut" is not particularly a healthy condition.  Venuto’s strategies do work for some dieter’s by supplying them a tactical means to control satiety, and can result in weight loss – but it is nothing more than one of several hundred tactical approaches to a reduced calories to aid in weight loss. 


I'm 5'9" and now 47. In 2002 I was about 275 and changed from a very sedentary job/lifestyle to a very physically active demanding job. I worked 8-12 hours usually 6 days a week. I was on my feet and walking the whole time and lifting/pushing things constantly. By the end of 2003 I was down to 153.

I was eating very healthy during this time period. It was a low fat diet. I was sort of watching calories, I occasionally would add them up and I was regularly eating a minimum of 1400 to 1800. I know I gained muscle during this period, because I became very strong. I always had energy.

I kept the weight off until late 2005. I started having trouble staying under 160. In early 2006 I quit that job and took a more sedentary job. I then had trouble staying under 180. Starting in early 2007 I really started packing on the pounds and found myself all the way up to 262 in January of this year, I can tell its all fat.

I'm now at an extremely sedentary job again and finding it hard to exercise. I know I need to add activity. I've been eating around 1600-1700 calories per day without added exercise, which is about a 500 calorie deficit. I saw 9 pounds drop very quickly, 3 weeks. The last 2 weeks basically nothing.

Do you have any suggestions? I'm thinking I should work on strength training first, as that is something I can do at home easily. In a couple of months it will be nice enough outside for me to walk and ride my bike.

see i have always beleved this way from the get go i havea post on it.

if you dont eat your going to lose weight i dont care,i do believe your metabolism does slow down,i do beleive in plataues, but i have always lived by that method

the less you eat the less you weigh,i hear people saying you gain weight if your on a very low calorie diet "rubbish" yeah when you go back to eating normal,but i try to stress this so much i'm not wanting people to starve them selves, i just want them to realize that you can lose weight,quit worrying about this starvation mode,but thats not telling you to go and do 500 calories a day,cuz i realize going on to much on a crash diet leads to failure, i only did it once and yes i lost every bit of weight i til i couldent lose nomore,but i quit working out and went back to normal eating and gained all my weight back and then some,i shouldent have ever quit.working out that is,and i tried to crash diet again and again,i just cant doi it ,it ends up failing the hunger always wins,so i realize i now will just go on a low calorie diet,which will be 1500 calories a day,but zig zag them,somthing i could handle. i sit back and say how the hek did i do it the first time,than  i realize i wasnt 311lbs either when i went on my first weight loss journey,so what im saying is yes you can lose alot of weight on a very low calorie diet,but dont go to extreme,do somehting you know you can stick to,thats what i realized i have to do.yeah i could do 1000 calories day,and go to the gym for 3 hours a day but i know in about 3 months i'm going to get tired and say forget its okay to go low but not to extreme


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First thanks to whoever posted for getting the information together but second it's not completely accurate.  The poster gave the example that they'd have to eat around 725 calories a day to lose weight. DO NOT do that.  BMR/RMR is what your body burns when resting. So unless you sleep all day then you're burning more caloires than that. Even with a desk job and no exercise at all you'd burn about 1.2 times your BMR/RMR a day. So if your BMR is 1450 then you're burning about 1740 calories a day and eating 500 calories less a day is 1240. This is the reason why most people reading are confused. No doctor or expert would ever recommend eating 725 calories a day.

Hope this helps... hp

Hi John,

I appreciate your posts and hope you could offer me a little counsel as well. I am a 24-yr old female, 5'4, 138 pounds. I have gained about 15 pounds in the past two years, but I don't know how this has happened. I eat sensibly and low-cal, usually about 12-1600 per day, do 60 to 90 minutes of cardio and/or weights 5-6 days per week, and work a desk job but try to live a pretty active lifestyle. Since January 12, 2009, I've been consciously eating an average of 12-1300 calories per day and working out the same amount or harder. I've lost maybe a few pounds, but I can't even tell if it's water weight or real fat, and lately I seem to have hit a plateau. My husband now thinks that I might be in starvation mode, and that my metabolism is shot, and that I might need to try to get back to eating a real number of maintenance calories for someone of my activity level, weight, height etc...maybe 1600 or 1800 per day. Then, from there, once my metab revs back up to normal, I could try dipping back down to 1200, or I could try calorie cyling or zig-zagging. I have a feeling that this could be the right move, but I'm scared because I don't know what the consequences of these actions will be. Will I just gain more weight? Or will it "fix" my metab?

I really do feel like my metabolism is very slow... I am always cold, I am never really very hungry even on the few cals I eat, and my cycle is irregular and sometimes skipped. I had a TSH test done last spring and the results were indicative of a healthy, on-the-active-side thyroid. However, I've read about different hormonal imbalances that are caused by different hormones and glands (pituitary for example) that do not show up on the TSH test but could still cause similar problems as a lack of thyroid hormone. A part of my wonders if this could be the case, although I know your hormone levels could be ok but you could still have a slow metabolism... 

That last paragraph was a little divergent... but I am wondering if you know anything about calorie cycling or speculate that this could have to do with hormones, and what you might recommend I do as far as what next steps to take, how many calories to consume to get my body back to normal (and how long I should stay at those levels--weeks? days?) if it is indeed "starving," etc. I have an appt with a nutritionist next week and I hope she can offer some counsel as well. I'm a little worried that she'll tell me the same thing I could read in a copy of Health magazine... consume fewer calories, expend more, etc.

Right now i'm just so frustrated, because I feel like I'm unable to live a normal life. I can't eat normal levels of food, I don't even get very hungry, I work out so hard, I'm cold, etc. Something isn't right. Thanks in advance for your time.

Thanks for posting. I think starvation mode is a totally overused term here. I know it's possible to wreck your metabolism but it doesn't happen overnight as some posters tell others.

This was extremely helpful. It answered all the questions I've been dying to know. Thank you, really!

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