Starvation Mode: How It Works

jlsmiles22

Thanks for the awesome explanation.

ladyhawk00

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kje2011

We’ve all seen the countless threads and posts about starvation mode. Many contain a lot of misinformation and apply the concept too broadly. It’s my aim to clear up some misconceptions (of both believers and non-believers). I’m going to try to keep this simple and straightforward and easily understandable.

What is Starvation Mode?
Starvation Mode – aka survival mode, famine response, adaptive thermogenesis

Starvation mode is a reaction to inadequate energy. If your food intake is too low to meet energy requirements, the body starts accessing inside sources. It will attempt to access fat stores first, and in the highest proportion. If you have a lot of fat stores, most of the energy will come from fat, and a little from muscle. If you have less fat stores, most will still come from fat, but a higher percentage will come from lean tissue, such as muscles. The leaner you get, the more difficult it is for the body to access fat quickly.

When the body perceives intake to be too low and energy stores (fat) to be inadequate for making up the difference quickly, it begins to compensate to prolong survival. First, it slows metabolism (the rate at which you use energy.) If intake continues to be too low, it then begins to access muscle, because it is easier and faster. The loss of lean tissue further slows metabolism. If this cycle continues for a significant period, at the right levels, it results in an ever-decreasing metabolism. This means a person can eat less and less (to a point), and still have slow or no weight loss because the body’s energy requirements have decreased. Remember that total energy requirements include BMR, daily activity and purposeful exercise.

Who is at Risk?
Most people with large amounts of fat stores are not at risk of starvation mode. This is usually women over 35% body fat and men over 25% body fat, but there is no exact point. They have sufficient energy stores to supplement the body’s needs for energy (however, they still have other needs that must be met, such as vitamins and minerals). The closer a person is to a healthy BMI, the higher risk and consequences of starvation mode.

When Does it Happen?
It doesn’t happen by skipping a meal or even a whole day or at 1200, 1000, or any other random cal number. Typically, metabolism will begin to decrease after about 72 hours of significantly inadequate intake. But this is dependent on the individual’s specific situation – what the energy requirements are, how much fat they have, and the exact level of intake. The loss of lean tissue begins sometime later. It could be days, weeks or months. It may be at 1200 for one person, and 2000 for another. Again, it depends on the individual and will be a different point for everyone.

Then Why are Anorexics Skinny?
Anorexics were “normal” weight at some point. They began decreasing intake and using up fat stores. How long this takes depends, again, on energy requirements and actual intake. The body has a “range” in which it feels comfortable accessing fat, without decreasing metabolism too much or burning too much muscle. As an average, this is between 250 and 1000 calories below maintenance requirements. When you drop below this range, the body begins starvation mode reactions. Anorexics WERE in starvation mode at some point – but they continued to decrease intake. There is a level of extreme calorie restriction and lack of fat stores at which starvation mode turns into actual starvation. The body is adaptable, but it has its limits. At this point, the body has no choice but to burn everything – fat, muscle, organs, hair, skin, etc - simply to sustain bodily functions. Severe anorexia is the result of continuous extreme calorie restriction and malnutrition (typically below 500 cals). You can try it their way. But remember, a lot of them develop horrible diseases from malnutrition and many of them die.

But Some People Claim You GAIN Weight in Starvation Mode?
Starvation Mode itself will not cause weight gain. However, a combination of starvation mode, binges, and carb loading, can cause weight gain. Once the metabolism decreases, your energy requirements are lower. So you have to eat less just to maintain your current weight. The body has become more efficient at using and storing energy. But most people have a hard time maintaining a very low intake consistently for long periods. So if your typical intake is 1000 (just an example), but you have occasional binges of 3000 and the binge is mostly carbs, the body can’t use all of that at one time anymore. So the body shuttles it to fat storage. This won’t be a huge gain, but a lb or two a month maybe. It’s not dramatic, but if someone lives this way for years, they can gain a decent amount of weight.


Further Reading:
http://www.myfitnesspal.com/topics/show/186814-some-mfp-basics
http://www.myfitnesspal.com/topics/show/61706-guide-to-calorie-deficits
http://www.myfitnesspal.com/topics/show/175241-a-personal-view-on-exercise-cals-and-underfeeding
http://www.myfitnesspal.com/topics/show/222019-60-lbs-in-60-days?hl=60+lbs
http://www.myfitnesspal.com/topics/show/3047-700-calories-a-day-and-not-losing
http://www.myfitnesspal.com/topics/show/10589-for-those-confused-or-questioning-eating-your-exercise-calo
http://www.myfitnesspal.com/topics/show/153704-myth-or-fact-simple-math-3500-calories-one-pound-eat
http://www.myfitnesspal.com/topics/show/173853-an-objective-look-at-eating-exercise-calories
http://www.myfitnesspal.com/topics/show/12250-1000-calorie-deficit-not-for-people-with-healthy-bmi
http://www.myfitnesspal.com/topics/show/208407-how-to-repair-a-damaged-metabolism-stavation-mode?page=1#posts-2752820
http://www.myfitnesspal.com/topics/show/187973-an-email-response-that-might-help-some?page=1%23posts-2493477
http://www.myfitnesspal.com/topics/show/8977-your-body-s-thoughts-on-calories
http://www.myfitnesspal.com/topics/show/777-why-is-starvation-mode-so-bad
http://www.myfitnesspal.com/topics/show/49690-the-banks-plan?page=1#posts-541471
http://www.myfitnesspal.com/topics/show/69708-calorie-deficit-for-dummies-a-little-long
http://www.myfitnesspal.com/topics/show/81391-starvation-mode-myths-and-science
http://www.myfitnesspal.com/topics/show/79181-dogmeat-s-thoughts-on-weight-loss

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ShoeDeahva

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kayi2601

Thank you for this amazing post. I was just questioning whether i should eat the calories i burn during exercise or not but i definitely will from now on even if i am above 35% fat...x

ivansmomma

This has been a great and most informative post. Right now, I try not to eat my exercise calories, but will continue to monitor. Being older, on meds, blah, blah, blah, it's always good to watch your own body and see how it reacts. Thanks again!

ladyhawk00

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BrokenWings

Faboulous post, adresses a lot of the issues surrounding starvation mode and healthy calorie intake in a clear to read manner. It should be required reading for all dieters/newbies/people looking to lose weight healthily.

ladyhawk00

Faboulous post, adresses a lot of the issues surrounding starvation mode and healthy calorie intake in a clear to read manner. It should be required reading for all dieters/newbies/people looking to lose weight healthily.

Thanks! Glad you liked it :blushing:

baisleac

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ladyhawk00

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akaTheQueen

Great info. . thanks for bumping. Wish I had seen it before I posted my "question" earlier tonight and got attacked. . .

ladyhawk00

Great info. . thanks for bumping. Wish I had seen it before I posted my "question" earlier tonight and got attacked. . .

Glad it helped... people get touchy about this subject...don't let it get to you. Good luck with your goals! :flowerforyou:

DragonSkip

But Some People Claim You GAIN Weight in Starvation Mode?
Starvation Mode itself will not cause weight gain. However, a combination of starvation mode, binges, and carb loading, can cause weight gain. Once the metabolism decreases, your energy requirements are lower. So you have to eat less just to maintain your current weight. The body has become more efficient at using and storing energy. But most people have a hard time maintaining a very low intake consistently for long periods. So if your typical intake is 1000 (just an example), but you have occasional binges of 3000 and the binge is mostly carbs, the body can’t use all of that at one time anymore. So the body shuttles it to fat storage. This won’t be a huge gain, but a lb or two a month maybe. It’s not dramatic, but if someone lives this way for years, they can gain a decent amount of weight.

This!!!!!

I did this and gained!!!!! The only time that I would lose weight is during Christmas or long vacations! I couldn't understand it until I joing MFP and read the boards.

I think this is the exact same thing as what happened to me! Years and years of going in and out of this for months at a time, with binges every week or two. I remember some summers when I was a teen when I would go days where I would only eat a few bites in front of my mom at dinner so she would stop nagging!

babygurl48

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baisleac

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ladyhawk00

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Angeloftheshore

Bump...great post ladyhawk00!

dodd319

Thank you so much for the information!

ladyhawk00

Thanks, glad you liked it

AI1108

This totally makes sense! Just a question..

so I have a 21% BF and have MFP set at 1 lb a week, which gets me to 1200 cals a day (my bmr is about 1380). For a while I would go below between 1050 - 1150, because I just wouldn't get hungry. One day I had 1900 calories in one day! The next day I had about 1250 calories and lost 2 lbs. I figured you might understand this better but what happened there?! any idea?!

ladyhawk00

This totally makes sense! Just a question..

so I have a 21% BF and have MFP set at 1 lb a week, which gets me to 1200 cals a day (my bmr is about 1380). For a while I would go below between 1050 - 1150, because I just wouldn't get hungry. One day I had 1900 calories in one day! The next day I had about 1250 calories and lost 2 lbs. I figured you might understand this better but what happened there?! any idea?!

Could be a number of things...you may have just had water retention and then unloaded it. But could also be a reaction to FUEL! lol

At 21%BF, your body really cannot withstand that kind of deficit. The less fat stores you have, the less "available" the fat is (ie it's harder for the body to access it quickly in reaction to a need for fuel due to exertion, etc). So you need a much more conservative deficit to keep the energy balance. If you don't have enough intake, your body won't be willing to access the fat - it will use more readily available sources (lean mass like muscle) and simply try to reduce energy expenditure (decrease metabolism and fatigue, etc).

So, when you do feed it, you'll likely see better results in overall weight loss, and definitely in body composition. I'd highly recommend going to at least 1/2 lb per week loss goal, or even maintenance, lots of strength training to maintain or even increase muscle.

At that high of a deficit, you'll likely start running into the body starting to maintain body fat - so you may lose weight, but it won't be fat.

AI1108

Thanks for the info! Hmm looks like I may need to up my cals..

_Jessica_

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ladyhawk00

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whisperingdragon

:flowerforyou:

pearlymae

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Thanks for the info.

cmriverside

GreenSkinnyJeans

Very informational, thanks for posting : ). I knew most of this, but the detail was much more of interest to me. XD

fairbanksmommy

I have a general question....Not directly relating to me, but something I can pass on to my 16 year old ex step daughter. What if one eats in their calorie range one day, then eats nothing the next, and so on? So every other day, they eat absolutely nothing?? What does that do to your body weight wise as well as long term?