Eating Below your BMR... Why is it bad?

kaydensmom12

Sounds bogus to me, I believe its just made up and spread over and over on the MFP forums.

Why would your body attack muscle first instead of fat for energy? That would be quite stupid

I can see it using muscle for protein it needs, but not energy.

I don't believe your BMR is the magical cut off for your body to start eating your muscle tissue, if someone can prove to me otherwise I stand corrected

Glucose is energy. When the body runs low on carbs/glucose then it may use amino acids in a process to make energy. No there is no magical cut off number, but what if you are consecutively not giving your body the glucose that it needs and it has to continuously break down the muscle for energy?
http://www.livestrong.com/article/554481-when-does-the-body-start-to-use-muscle-tissue-for-energy/
http://science.howstuffworks.com/environmental/life/human-biology/fat-cell.htm

juicemoogan

I like the way Vaclav Gregor (Greg) put it....All credit goes to Greg.


Metabolic slow down & “Starvation mode”
According to diet programs, you should experience metabolic slow down or starvation mode, when you are not eating regularly or eating below your BMR (explanations differ sometimes, which I found very entertaining btw). There is no study that would support that, quite the contrary. But instead of some research that you will not understand I’ll give you the most simple and logic explanation. Just look at the pictures of people who survived the holocaust or some tragedy and have been left for months or years without food. Did they trick the metabolism and starvation mode? I don’t think so. That means that eating less or fasting will not put you into “starvation mode” and your metabolism will not slow down.

It’s really nothing to be concerned about. These things exist only to confuse you and trick you into buying more food and supplements. It’s just business, sad but true. There are tons of researches and none of them will ever speak about things like starvation mode and metabolic slow down. In this researches when people lost a lot of weight there metabolism slowed down about 100 calories. That’s one large coffee. And I would say that it didn’t slow down, it just came to the normal level from being overweight. Why? Because BMR (Basal Metabolic Rate) is calculated by your height and your lean body mass. So when you lose weight, your lean body mass number decreases.

I'm sorry... have you seen those pictures of people from the holocaust? They sure looked starved to me. No muscle, no fat, just skin and bones. What did their internal organs look like? Is that what you would like to look like?

What everyone is saying you CAN eat below... but it is NOT recommended for Health reasons. No one wants you to look like a Holocaust Survivor or end up in the hospital because your organs have shut down since they were not needed.

But the “Starvation mode” idea here is that you can not loose weight in starvation mode. You have to increase those calories above the BMR. to loose. That is not true. It may be unhealthy but if you have a lot of weight to loose it can be done.

No one said you CAN'T lose weight in starvation mode - you can, its just unhealthy and you will probably end up in a plateau and not lose any MORE weight after a certain point. Your body will also be "starved" of the essential nutrients it needs to function.

wild_wild_life

Good question. I don't think that your body is breaking down only fat if you eat above your BMR and only muscle if you eat below it, I think it is a mix of both either way.

That point aside, why would you want to eat fewer calories than your body needs for the most basic functioning?

Why not? You body can get calories from fat stores, its not going to just shut down if you eat under your BMR

No, it won't shut down, and assuming you have enough fat I'm sure your body will take from that, in part. I'm just not sure why anyone would prefer that to providing your body the energy it needs at least for basic organ function. But to each his own!

manthajill

I did some research on this awhile back. I had started gaining weight, and the advice I got was that I wasn't eating enough. I'm training for a half marathon, so I was doing some long runs, without eating any extra on those days. I've read that starvation mode, as it's typically understood, is a myth. However, I also read that if you eat less than half of the calories you've used in a day, your metabolism WILL start to slow down. It won't slow down enough to stop you losing weight altogether, it will just be slower than predicted.

The other factor to consider is cortisol, a hormone that the body releases under physical or psychological stress, which can wreck havoc with weight loss. I that it's cortisol that would explain why I was gaining weight when not eating extra on long run days. It was my first half marathon, so I was putting a lot of new stress on my body with the running, plus, it wasn't getting the fuel it wanted. This was combined with the fact that I was eating just below half of the calories I would have needed to maintain my weight with that level of activity, so my metabolism probably was slowing down to some degree.

In terms of eating below your BMR, if you did it for a long period of time, I'm sure you would eventually lose weight. However, in the short term, your body might react to the stress by releasing cortisol, which might actually cause weight gain. Personally, I think it's important just to listen to your body and observe and respond to what's happening for you.

Masterdo

Sounds bogus to me, I believe its just made up and spread over and over on the MFP forums.

Why would your body attack muscle first instead of fat for energy? That would be quite stupid

I can see it using muscle for protein it needs, but not energy.

I don't believe your BMR is the magical cut off for your body to start eating your muscle tissue, if someone can prove to me otherwise I stand corrected

Fat doesn't need much energy to sustain, that's why energy is stored this way to begin with. Muscles on the other end, contribute to your metabolism. Eating muscles not only gives more energy, it also reduces the metabolic rate. But it doesn't attack muscles FIRST. It just attacks them too.

And if you are doing the most perfect diet out there, eating the most perfect way possible to lose weight, you will still lose a % of fat and a % of muscles, it is inevitable. Just like when you bulk up to get muscles, you gain fat too. The trick though is that your nutrition and workout schedules can be used to tweak those numbers and lose the most fat when you lose, and gain the most muscles when you are going back up.

And for the dude mentioning fattening for winter, how nice is it to leave out the most important part : That they use external (temperature) and internal (slowed down metabolism) to actually lower their caloric needs and thus survive:
http://www.springerlink.com/content/m8218m7106171276/
http://physrev.physiology.org/content/83/4/1153.short

But yeah, like you say, keep deluding yourself that science will say anything for a fat check

Edit to add : In fact, the first study even clearly mentions that they lower their BMR during torpor or hibernation, specifically the part about maintaining body temperature. But yeah, "slow metabolism" and BMR, those things don't exist.

gapm

Part of the problem in finding the research related to the effects of eating too little aside from weight loss seems to be that much of the research was done long before the internet. I remember watching a PBS show in the 1970's about research that was done either in the military or in a prison where they were looking into very low calorie diets. One of the findings was that even though everybody on the same very low calorie diet over the same period of time with the same amount of exercise, but did not have the same results. In fact, some of them lost next to nothing. The explanation was that their metabolisms had changed to accommodate the reduction in calories. I wish I could find something that could give you the details about the study without relying on my memory.

Another part of the problem is trying to find hard facts and scientific research among all the other chatter on the internet. There is a massive amount of stuff to sort through.

Edit: I did a little more looking and this article "Why do obese patients not lose more weight when treated with low-calorie diets? A mechanistic perspective" from American Journal of Clinical Nutrition, Vol. 85, No. 2, 346-354, February 2007 looked like it was relevant: http://www.ajcn.org/content/85/2/346.full

I actually found the study I was looking for: http://en.wikipedia.org/wiki/Minnesota_Starvation_Experiment

Another related link: http://www.stress-free-weight-loss.com/

londongirl2012

Hi all
iI need some advice, I am really confused now...I am only 4ft 10 and weigh 50 kg and my BMI is currently 23.5 and would like it to be lower. My BMR according to MFP is 1332 and I am sedentary but walk about 3x a week so my TDEE is 1410 kcal's, so to lose weight I know you should eat 500 less to lose 1lb per week, but I know its bad to eat under 1000 and so I try and aim for 1050 net, but now I'm confused, should i be aiming for more??
I don't want to lose 0.5lb per week, i am going on holiday in 6 weeks and want to wear a bikini and feel confident, so far i have lost 2kg in 4 weeks at this calorie amount and am happy with it.
thanks

melkneec

I am just now starting to read the studies on the subject but I thought this little article was interesting. I have no opinion on the subject just yet. I have to read more research and studies. Not other peoples opinions of the studies.

http://caloriecount.about.com/forums/weight-loss/truth-starvation-mode

kenny_johnson

BMR is what your body needs to simply survive. That is what would be burned if you just stayed in bed and did nothing. Your body NEEDS those calories to work correctly and keep the systems going. When your body can not get the calories it needs, then it looks for them wherever it can get them. That could be fat, but it also will be muscle and other systems. The thing is, it will not be just fat!

Your TDEE is where you take your deficit from. This is how much you burn based off of your daily activity.

This is pretty much what about 75% of the responses to my question said. And it's pretty much what my original post was responding to. If you are in a calorie deficit (AT ALL), your body needs to get that energy from somewhere. It's not ONLY if you are eating below your BMR. If you are eating above your BMR, but still in a calorie deficit, your body is deficient of energy and needs to get it from your body tissue. Some of it will be fat, some will be muscle/bone/lean body mass.

My question is.. To those who say you HAVE to eat above your BMR --- why? If you need a deficit to lose weight, why would a deficit below BMR take from muscle but a deficit above BMR take from fat?

drapes73

Why does the body generate energy by burning calories from fat if you go for a walk but will get this energy from your muscles to perform it's daily tasks?

I'm not convinced it does.

Bridget0927

Sounds bogus to me, I believe its just made up and spread over and over on the MFP forums.

Why would your body attack muscle first instead of fat for energy? That would be quite stupid

I can see it using muscle for protein it needs, but not energy.

I don't believe your BMR is the magical cut off for your body to start eating your muscle tissue, if someone can prove to me otherwise I stand corrected

Agreed.

kenny_johnson

Part of the problem in finding the research related to the effects of eating too little aside from weight loss seems to be that much of the research was done long before the internet. I remember watching a PBS show in the 1970's about research that was done either in the military or in a prison where they were looking into very low calorie diets. One of the findings was that even though everybody on the same very low calorie diet over the same period of time with the same amount of exercise, but did not have the same results. In fact, some of them lost next to nothing. The explanation was that their metabolisms had changed to accommodate the reduction in calories. I wish I could find something that could give you the details about the study without relying on my memory.

Another part of the problem is trying to find hard facts and scientific research among all the other chatter on the internet. There is a massive amount of stuff to sort through.

Edit: I did a little more looking and this article "Why do obese patients not lose more weight when treated with low-calorie diets? A mechanistic perspective" from American Journal of Clinical Nutrition, Vol. 85, No. 2, 346-354, February 2007 looked like it was relevant: http://www.ajcn.org/content/85/2/346.full

I actually found the study I was looking for: http://en.wikipedia.org/wiki/Minnesota_Starvation_Experiment

Another related link: http://www.stress-free-weight-loss.com/

The thing about these studies -- and what they actually call starvation mode is that these people were eating WELL below their BMR. The minnesota study had them eating, at one time, about 50% of their BMR. These were already lean people -- so they were probably on about 800 calories or less. I'm not suggesting that isn't unhealthy.

Instead, I'm questioning the wisdom that I keep seeing repeated that you HAVE to eat your BMR to lose weight healthily and safely -- because not doing so will either make you lose more muscle/lean body mass or put you into starvation mode.

MFP has below my BMR and that's what I've been doing. But I'm also exercising and doing resistance training. It may just be in my head, but my biceps feel bigger to me. I just started tracking my fat percent with a new scale. Out of the last 5 pounds I lost, if the scale is accurate, much less than 1 pound of that was lean body mass. The great majority of it was fat.

kenny_johnson

Why does the body generate energy by burning calories from fat if you go for a walk but will get this energy from your muscles to perform it's daily tasks?

I'm not convinced it does.

Exactly. It's as if the body is saying -- to keep the heart pumping, I'm going to take energy from the muscles, but to fuel your workout I'm going to use food or fat.

Masterdo

My question is.. To those who say you HAVE to eat above your BMR --- why? If you need a deficit to lose weight, why would a deficit below BMR take from muscle but a deficit above BMR take from fat?

Oh, you don't. An absolute answer would definitely be that you don't HAVE to. Studies don't show either that fat loss stops when you do, just that it slows. And other studies show very nicely how stuff like HIIT, circuit training, etc. can help increase total metabolic activity and help losing fat. But still, muscles too, like you pointed out. It's just the ratio that changes.

People that say you HAVE to, mostly mean that it's the best way to go I guess.

dansls1

One of the things you need to understand is that the BMR calculators are all estimates. And the calories you think you eat are estimates (probably usually low estimates). So if your BMR calculates at 2000 calories and you eat 1700 you are probably really eating 1900. Then you exercise - and overestimate the amount of calories burned. So by the time you put all those estimates in, you probalby do not need to eat more if you average around 1700 and the BMR calculates to 2000. If it is a huge difference, like you are eating 900 calories with a BMR of 2000, then I might think about eating more.

kenny_johnson

Studies don't show either that fat loss stops when you do [eat below your BMR], just that it slows.

Which studies?

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cmccorma

Why does the body generate energy by burning calories from fat if you go for a walk but will get this energy from your muscles to perform it's daily tasks?

I'm not convinced it does.

Double agreed.

Masterdo

Studies don't show either that fat loss stops when you do [eat below your BMR], just that it slows.

Which studies?

[/quote]

I linked them already in this thread in fact. Mostly on the link with anorexia and other eating disorders, where it affects production of cortisol and other metabolic regulators. Give it a read

cmccorma

Another thought; there are a few people who have posted that they had their BMR tested professionally. One was something like new leaf testing. In any case, their BMR's were a lot lower than some I have seen by just putting your measurements into a website. One girl who was very close to goal had a BMR tested at 1,100! I am thinking that everyone is different and just like eating 1,200 calories doesn't not work for everyone, using a formula off of a website does not work for everyone either.

kenny_johnson

I linked them already in this thread in fact. Mostly on the link with anorexia and other eating disorders, where it affects production of cortisol and other metabolic regulators. Give it a read

Maybe I'm not finding them. I found 2 that had to do with hibernation and one that was a link to a google scholar search (not an article) for anorexia (not eating below your BMR).