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'Starvation' Mode


For years we've heard about "starvation" mode, basically where people under eat to the point where they slow metabolism and it makes weight loss difficult.

In theory it makes since as long term calorie deprivation can mess with hormones, and seems like a logical change by the body to help survive during periods low food supply.

so, for years I've sensed from what people tell me they eat and struggle to lose weight that often it is that their body is in "starvation" mode.

But, if it is simply calories in/ calories out, would reducing calories to a low enough amount at some point cause weight loss?

Because we see people in "starvation" mode throughout history (concentration camps, anorexics) and they don't seem to be holding on to an addition 20-30 lbs of body fat.

thoughts? Is there really a "starvation" mode, or is it simply people not reporting how much they're eating in a accurate way.


I just see starvation mode as when your body starts relying on vital tissues (tissues that it would normally not use for energy) for energy. Essentially, the body starts eating itself. And yes the metabolism slows down when you enter starvation mode, as a way to conserve energy, but some people assume that you gain loads of fat right back when you increase caloric level. I don't believe that. When a body is taken out of starvation mode from increasing nutrient intake, it wants to replenish VITAL organs. Your fat stores are not even close to importance as your heart, brain, liver, and kidneys are, so laying down fat tissue is one of the last things the body does when it is presented with an increased nutrient intake.

So yes I believe starvation mode exists, but its pretty damn hard to enter.


You would lose weight if the calories are low enough but, you will get to a point where calories are to low for everyday activities and muscle loss would be ridiculous. Every time I have seen the word "Starvation Mode" used it was in regard to diet/fitness.


Here is the flaw: people who are actually starving still lose tons of weight, like you said.

What's more likely here: the body somehow circumventing the laws of thermodynamics? Or fat people not having an accurate or realistic handle on what they ate putting in their mouths?


I think often times what people consider "starvation mode" is really their body's thyroid shutting down from prolonged caloric deficit.


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check out martin birkinheads site at leangains.com hes got loads of stuff n links to tests RE RMR and fasting etc .
it opened my eyes


What the fuck? That was not on my Word of the Day calendar.

I've submitted it to the manufacturer for the Leap Year addition.


I expect the fourth or fifth discussion on "Is calorie just a calorie" this week to start within the next 15 minutes.


Yes, metabolism slows down when dieting. In normal dieting, this is generally a fairly small slowdown (100-200 calories a day). In anorexic type situations it can be worse, but then you're more closely resembling true starvataion, where the body is trying to juggle depletion of fat, musle, and organs, so that they are all exhausted at the same time (resulting in death, of course).


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I don't think anybody in actual "starvation mode" is having trouble with being over weight. I think some eat so little, slow their metabolism to a halt, and then eat high calories meals when they do eat causing the weight issue.

Friend of mine never ate breakfast, drank pop all day, and then came home to a big unhealthy meal late in the evenings. Even though he worked concrete all day he was around 45 50 lbs over weight. I told him to cut the pop, eat anything for breakfast, snack at work, and eat a lil cleaner at night. By my wedding he was down 40 some lbs.

Some may have hormonal issues among others, but for the most part my friends lifestyle is all too common.


"Starvation mode" is a horrible term for the phenomenon where leptin drops after a few days of dieting. It's not really "starvation"; it's just really the body's way of indicating to itself that energy sources are scarce. Eat more food every couple days and the problem goes away. Keep restricting intake and the body adjusts its metabolism for lower average intake. That's it.


when im on a cuttin phase i do it IF style . for me it makes droppin the fat a piece of cake .
i always thought it was a bad idea but i tried it and found it works for me.
after about 11 or 12 hours of fasting i really feel a sort of lift in energy and its easier to think and concentrate similar to if you pop 200mg of caffiene or have a couple of coffees.
Ive read several studies on pubmed that prove RMR actually increases as a result of short term fasting and dosn't actually drop until fasting continues for quite some time .


You rock. That's all I have to say.


To truly understand the physiological effects of starvation I suggest the following book:
'Hunger Disease: Studies by the Jewish Physicians in the Warsaw Ghetto'

It's rather old, yet enlightening. Definitely not for the faint of heart.


The most fascinating look at "starvation mode" was from a recent study interpreting data from the old Minnesota Starvation Experiment (MSE). Healthy, normal (not overweight) men were basically imprisoned for months, over 6 months IIRC, while they went through the following calorie phases:

  • ad lib calories were recorded (eating whatever they wanted in the cafeteria)
  • calories were severely restricted for several months. Body fat was shed initially in a sharp drop, but then completely plateaued as LBM continued to be shed.
  • calories were raised, but not quite to the previous ad lib level. The body rapidly restored fat BUT NOT LBM as soon as calories were raised.
  • the subjects were allowed to eat ad lib again. They ate MANY more calories than their previous ad lib, and their bodies continued to add fat until body fat reached its previous level from the beginning of the study. THEN the body proceeded to add back LBM, BUT 1) it continued to add fat while adding back LBM, and 2) at the end of the study, LBM was still slightly less (97% I think) than baseline, while fat mass was higher (like 110% or something).

So, body comp was worse after a period of severe calorie restriction.

I've also read informal discussion (not published scientifically, so don't know if it is true) that subjects suffered from a variety of long-lasting ill effects from the experiment.

The recent analysis of the data tried to look at mechanisms in the body for this apparent memory for fat mass and LBM and what exactly happens as the body fights to maintain it or regain it.

The experiment also matches exactly what I have seen happen in many obese friends and family members who have "crash dieted," and that includes many hospital-sponsored PSMFs, of which I have a very low opinion. Yes the weight comes off -- as it did in the MSE -- and it goes back on even faster than it came off.

Regarding "a calorie is a calorie," it would REALLY HELP if people could realize that it is JUST A MODEL of energy metabolism and expenditure. It describes pretty well (not perfectly: no model is perfect, nor should they be) what happens, on average over a period of time, in a person in a "normal" metabolic mode. The model has its limits of conditions under which it can make a useful prediction. The MSE described above shows exactly that severe calorie restriction DOES CHANGE the body's energy expenditure. You could call this "starvation mode."

It is also a near-universal truth of dieting that after a period of calorie restriction, your calorie expenditure will fall. I have been curious about this, so I bought a GoWear Fit calorie expenditure device and tracked my calorie expenditure while dieting. I decided to try severe calorie restriction. My expenditure remained stable for 3 weeks. Then it dropped like a rock. A lot of the drop comes from less movement and activity. Without the graphs from this device, I would never have been aware of this. It FELT like I was just as active as usual. Part of energy conservation is slowing and reducing movements. I also noticed a drop in BMR (calories burned while sitting or sleeping). You might think it would be easy to overcome the movement reduction by purposefully moving more. And to some extent, you can, especially with feedback from the device. BUT, even while you move, your energy expenditure goes down. So for the SAME activity or SAME exercise with the SAME perceived exertion (or greater!), you burn fewer calories.

Now some people interpret this drop in expenditure as proof your thyroid is crashing or leptin or whatever -- you're killing your hormones. They might be involved in this energy conservation somehow, but I don't think that's really the concern. I didn't have my thyroid tested, but I DID NOT notice any drop in my body temperature (morning, daytime, or activity) even while my calorie expenditure dropped significantly.

Still, the calorie model holds here for fat loss. Calories in was the same, but calories out dropped a lot, so weight/fat loss slowed. You have to either drop calories further, or increase expenditure through more activity.

So for short-term dieting, I think that conservation mode is a better term than starvation mode. Starvation mode is to be avoided, through a more moderate calorie deficit. Conservation mode is unavoidable, and the only solution is eating less and moving more.

I also firmly believe that most overweight people, and even many athletic types or bodybuilders, will have the best results losing fat at a fairly slow rate. I think the pound-per-week typical recommendation has a lot going for it. I firmly believe that you can MINIMIZE the LBM-wasting panic mechanisms seen in the MSE by taking a slower, more patient route. By "the best results losing fat," I mean minimal loss of LBM, minimal loss of perceived energy (which leads to less EE anyway), AND least rebound hunger that drives you to eat like a pig till all your fat is restored.

As far as people who believe that they are dieting but not losing weight, I find the answer is always simple. It's not crashed hormones. It's just that normal, natural conservation mode that is INEVITABLE with dieting: you WILL expend less energy, and you WILL have more hunger and drive to eat, even if you are not conscious of it. That's how the body works. And if it didn't work that way, people could die of starvation from an ill-advised low-calorie diet. The body protects itself from this extremely well. You cannot change this.

So if someone claims to be eating very little but not losing fat, but then I require them to measure every single molecule that goes into their mouths, and record it (say in Fitday), they find that ON AVERAGE, over say a week, they are eating many more calories than they claimed. I've had people PM me, then refer me to their blog...in their PM, they list a diet that should have them rapidly wasting away, like plain lettuce, chicken breast, 6 almonds, stuff like that. Then I go over to their blog, where they describe the "WHOOPS" moment of eating an entire (large) bag of Dorito Chips. They do not seem to realize that although they suffered through 6 days of low cals, they blew their entire deficit for the week with that bag of Doritos. This is Leigh Peele's whole thing, and she's right. When you make people record everything, the slow rate of fat loss becomes clear.


Hi my friend, YGM when you have the time. I stopped checking my email when I didn't hear back from you, only to find it the other day!

In response to your comment, true starvation mode is also consistent with elevated gh and catecholamines, which will elevate FA liberation and HSLipase activity. But I assume your point was in disrupted macronutrient percentages, not true extreme hypocaloric restriction.


Good posting Andersons.