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

great question, and I haven't ever found anything that makes sense to me either as far as a defecit and where it comes from. Hope there are some good answers

Your body needs X amount of calories to survive (your BMR). If you do not provide your body with this energy (calories are a unit of energy) via food, it will find it elsewhere. That “elsewhere” it finds it is your muscle (aka lean tissue).

OK, so now you are eating below your BMR and losing fat and muscle. By reducing the amount of muscle your body has, you are lowering your body’s energy requirement. This is known as killing your metabolism. This is why strength training is recommended for people losing weight. The more muscle you build, the more energy your body needs, the better your metabolism.

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.

EXACTLY!!!!!!!

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?

I always go back to the anamalistic way of thinking. Animals fatten up for winter when food is scarce so that the fat can be used for energy. Is there any difference when I reduce my calories so my body will tap into my fat stores for energy to survive.

I also have a problem wrapping my brain around this. I currently consume my BMR, but net below it after exercise.

If all this is true I do not understand why MFP and other mainstream experts set goals well below what many individuals BMRs would be. The only programs I have seen that sets your calorie intake goal off of BMR and TDEE are bodybuilding or heavy lifting programs, and not all of them do.

I am by no means saying it isn't true, I just don't understand why it isn't more widely known away from MFP and used more often in mainstream fitness/weight loss if it is based in research.

And while I'm at it. Why do all the people say you "have to eat 1200 calories". It is alway at least 1200 calories. The state it before even knowing the facts of the person.

My 65 year old 4'11 mother that does nothing and trying to loose 30lbs does not have to eat 1200 calories.

get off the 1200 calorie bandwagon people. Get facts before you state 1200 calories.

Your BMR is the amount of calories that you body needs in order to survive. In order for your heart to pump, for you hair and nails to grow, for you liver and kidneys to work. So if you eat below your bmr, what are you doing to your body? You are stressing it and it needs to get the calories and energy (glucose) from somewhere. When the body runs out of glucose, it can use amino acids which is what protein is made up of, for energy. So it does not pick fat b/c it is not made up with the high amount of amino acids therefore does not have the energy in it that the body needs.
So the quote is saying that the body will take muscle which lowers your calorie intake, because muscle burns more calories throughout the day than fat. The number of calories that 1lb of muscle burns throughout the day varies with the different sources, but from what I have read anywhere between 10-80 calories.
So yes you should not eat below your bmr b/c it stresses your organs. You should eat between your bmr, which is what your body needs to survive and between you tdee (the total amount of calories burned each day). This way you will have a deficit but will not be causing organ problems.

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

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.

Pretty cool answer, especially considering most initial studies on starvation mode and slow metabolism actually comes from those holocaust survivors.

The first studies were done with them, how they survived (slowed metabolism) and recovered. Then nowadays studies are done with people with eating disorders, like anorexia. Take a look at any of the studies on this search, for starters : http://scholar.google.ca/scholar?hl=en&q=anorexia+metabolism&btnG=Search&as_sdt=0,5&as_ylo=&as_vis=0

The reason why it's "bad" is just because it's really not an efficient way to lose weight, especially on the long term. In a 24 hour period, your Metabolism is really what burns the most calories, not your activities, not your workouts. Circuit Training and HIIT were developed specifically to rise your metabolic rhythm for the longest period possible.

So the best route is really to eat well, eat plenty and do some well planned workouts to burn more efficiently. But, if you look at things objectively, holocaust victims surely DID lose weight, lots of it. Fat, muscles, BONES. If you are going for health and fitness though... Not the way to go.

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.

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.

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.

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/

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

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.