Why not eat below BMR?

lizzardsm

Have you thoroughly read this?

http://www.myfitnesspal.com/topics/show/654536-in-place-of-a-road-map-2-0-revised-7-2-12

From my understanding, muscle is more calorically dense than fat. So when eating below BMR your body is going to reach for the easiest source of calories to keep you and your organs functioning - and it will deplete both lean body mass and fat. Eating above BMR combined with strength training gives you the best bet for maintaining your BMR while in a calorie deficit (you cannot really add muscle mass when in a deficit, only strength gains). In essence, eating below BMR eventually slows your metabolism - and causes your weight loss to stall.

KenosFeoh

I do know why the body will burn muscle before fat. The fat reserves are a last resort against starving. The body will burn muscle first because muscle is metabolically active. The more muscle you have, the faster you will burn through that precious fat to stay alive. So the body reduces muscle mass first.

It's really a delicate balance that we have to find in order to burn fat while retaining muscle. Not eating less than your body requires to stay alive (BMR) is part of that balance.

paperpudding

am not sure of exact science and number crunching - and I dont follow the BMR/TDEE method many on here do - I just eat how many calories the thing tells me to eat for my age gender ,activity level etc plus any 'exercise earned' caloires - number happens to be 1540 plus excercise calories - but it makes sense to me to have a point where eating below this would be detrimental to your health - I like the way MFP recomends slow and steady weight loss, not drastic methods of extremely low caloric intake

I mean, obesity is not good but neither are eating disorders.

Hmmm, not sure if that answer was on topic or not.....

Lupercalia

I'm not into the whole "starvation mode" myth. The reason I don't eat below my BMR is that it causes your metabolism to slow over time. I don't think any of us on this site want that.

I also feel like crap when I don't eat enough calories...get very "hangry" and feel tired and blue.

2EggsSeparated

you could die

cmon, i heard you'd lose a limb at most.

How much do limbs weigh?

AnnInTexas

I actually started "medically supervised" weight loss last week with a doctor.
As part of my pre-planning my program, she set me up to have a RMR test -- that's where they determine your resting metabolism rate -- or the energy burned by your body just sitting down quietly. I'll be happy to share the findings:

My weight: 238 pounds
My height: 5'4"
My RMR: 1800 calories.... that's what my body needs to function.
An additional 540 calories was added to the total as "lifestyle & activity" -- getting up to go the copy machine, climbing stairs to the 2nd floor, etc. That's a total RMR of 2340 calories.

The determination is:
1800-2300 calorie daily intake will maintain my current weight.
1440-1800 calorie daily intake is the "weight loss zone."
Anything under 1440 daily calorie intake should be medically supervised.

I'm going back this Saturday to the gym, to have a VO2 test -- that's where they determine your optimal heart rate for weight loss. Most people tend to exercise in the cardio zone -- which is certainly great. But for someone like me who still needs to focus on weight loss - I need to work out at a different heart rate.

I think the key is "medically supervised." I also underwent a complete blood workup and EKG... which will all be repeated in a couple of weeks. As part of my plan I meet with a nutritionist every week and either the doctor or the PA. I am NOT doing the VLC diet, frankly because that kind of scares me... but knowing this other information is pretty helpful in helping me with my day.

AngryDiet

It's some sort of weird irrational claim that has really gained a lot of traction here. I've never seen anything that backs it up, other than some strange irrational beliefs about comas and "starvation mode."

There are certainly issues like losing LBM which should be considered. But that is a conversation about caloric deficit and LBM. Not about BMR. BMR is irrelevant and just muddles the conversation.

It seems to me that TDEE is a far more valuable number than BMR. With your TDEE you can predict weight loss, and you can predict LBM loss as well. With TDEE you can get a sense of what is right for you and what is inappropriate.

While TDEE can be derived from BMR, TDEE can be directly measured by anyone, while BMR cannot. All you need to do is track your weight and log religiously for a few months, and you'll get a pretty good idea of your TDEE. You don't need to use "best fit" formulas and you don't need to guess which cookie cutter activity level you actually are. (Odds are you are between two anyway).

I've been eating slightly below BMR for over a year now. I've been losing between 1 and 2 lb a week for most of that. Oddly I'm still alive. YMMV.

twinketta

This is the short answer, you sound educated, so you would not need me to tell you any of this?

No, it has nothing to do with education! If I was actually educated in this arena, I wouldn't be asking the questions, so rest assured that I am most definitely not. My reasons for asking is that I am trying to take a good, hard look at the principles espoused in this Community, and I feel that some of the fundamental precepts, like this, are just stated as accepted fact with no inquiry into where this comes from.

I don't think it is that your body begins to "cannibalize" the organs. The problem is that there is a certain amount of fuel that your body needs just to function. When you don't supply it, but you still expect it to do its job, you put a strain on those organs and jeopardize your health and doing damage to the body. It takes energy even just to burn the fat you want to use, just like it takes energy to digest and use the food you eat. Conversion, consumption, digestion, and waste systems all require energy. Expecting to get energy from them while not providing energy to run them is like expecting a combine harvester to plow fields so you can eat without putting any gas in the tank. I'll see if I can find any links that are more authoritative and scientific than this... but that's my basic understanding.

Cannibalize may be the wrong words, but the point is that BMR is spoken of as a threshold under which the body is detrimented, and starvation mode begins (some implying it is just around the corner, even). You are right that the body needs a minimum amount of energy, it must. However, even taking into account both the energy to mobilize fat and the rate at which the body is able to do this - which is what you I think are getting it - there isn't, on the face of it to me, any basis to see BMR as anything other than a useful number from which to calculate one's total daily energy expenditure. I don't see how from where a conclusion is drawn that it serves as some sort of threshold above which the body will grab from organs or feel the need to downregulate and enter "starvation" mode.

It really seems that you are very educated...and I am sorry to emphasise this point.

You will know this anyway, BMR has been calculated for a reason as our basic metabolic rate, this has been calculated scientifically, whether it is up to date I do not know?

Starvation mode is a little more hard to define, I am not aware of any hard facts in this century that it does exist?

But as I said in a previous post, if you eat below your BMR then you are depriving your `organism` generally of nutrients that it needs to `survive` in a healthy fashion.

ninerbuff

IF you had lots and lots of weight to lose, or say you're a person who doesn't exercise and has a sedentary life, then in those cases eating under one's BMR may not be a big deal.

IE. Person's BMR is 1500. Sedentary life brings TDEE to 1900. Person wants to lose a pound a week, so takes in 1400 a day.

A.C.E. Certified Personal/Group FitnessTrainer
IDEA Fitness member
Kickboxing Certified Instructor
Been in fitness for 30 years and have studied kinesiology and nutrition

FromHereOnOut

Interesting topic.

I have been experimenting on myself and am (finally) seeing some results after increasing calories in. In my experimenting, my calories have been all over the place and I'm trying to come to a number that I can put as a baseline, which is why I'm interested in your thread. I'm wondering about netting below BMR, because this month I'm working out much harder than the past 2 months. I have a feeling I'll be netting below BMR because it might be too much to try to eat. However, I won't be EATING below BMR. To the contrary, I'll be eating quite alot and will give my body plenty of fuel and NUTRIENTS and the rest of what the body needs for my extra work outs can come from fuel storage (fat). I think this will work well.

As for the reasoning for not eating below BMR...I DO think it's about wrecking your metabolism. Your body is a magnificently adaptable organism. If you cut cals way down, your body will create energy-sparing and will remain there even after your cals increase to a more sustainable eating style. The new energy-sparing mode of your body will then have to store the "extra" calories that you introduce. In other words, the low cal diet will work upto a point, where you'll either plateau/stall, or you go into maintenance calorie level and you'll put on weight again. The other factor is stress to the body and the hormone changes that it creates. Stressing the body increases cortisol, which messes with metabolism and energy usage v. storage. This is all just my understanding of it. I don't have any studies, and in fact what I have read seems to suggest that scientist in this field don't entirely understand it, for example whether the increased calories (above VLC) flips some metabolic switch...or simply causes the body to create more movement (toe tapping, body swaying, etc) that adds up to higher expenditure. You could probably keyword search PubMed and find some things, but I've found that I had to just bite the bullet and experiment. I was terrified at first, but it worked out. My husband is a K.I.S.S. kinda guy and his take on my journey is this: eat the way you were eating (I wasn't eating alot of junk), but workout (I also wasn't working out). After experimenting, that's basically where I came back around to. I'm eating the way I was before, but working out (and working out more and more).

karenhray7

My understanding is that your body goes for muscle before fat, and will eventually get used to operating at a reduced efficiency because there isn't enough new food energy. I dont have any links for you, just what I've read over the years from here, books, and websites.

I think it's a choice, do you want to lose fat or muscle? I personally want to lose fat, so I dont want to eat less than 1200 calories or go into starvation mode.

If you look at people anorexic who eat very little or nothing, they lose weight... lots, they lose all their muscle first and then can be 'skinny fat'. eek!

Glycogen (energy stored in muscle tissue) is easier to break down and use than triglycerides (energy stored as fat).

babydiego87

you could die

cmon, i heard you'd lose a limb at most.

How much do limbs weigh?

an elephants peen.

kxlly

Truthfully... no reason. Doctors even prescribe VLC diets. which is under BMR.

Even a reported case of someone with a few vitamins and minerals solely living on fat for a year or something because he had so much to lose... And you know what? Maintained LBM....

It's myths that MFP decides upon and mods here enforce. They are not part of the medical science community, never will be and yet they pretend it.

Thank you.

Mads1997

Twinketta is right about losing your Lean Body Mass too. You will lose muscle, a lot more than you want to. That is another problem with radical cutting diets.

You will lose lean muscle mass if you do extreme cardio and eat over your BMR too.

hmm!! elaborate on that one???

The point is even if you are eating at your BMR or higher you will lose lean muscle mass if you do not do resistance training to maintain that muscle.

I have maintained my lean muscle mass for 4 months now while eating under my BMR under the care of my dietician. Previous to that I was eating above my bmr doing lots of walking and still losing lean muscle mass.

Edited to say: I have another 13 kilos to lose, that's a lot of fat stores right there.

karenhray7

[/quote]
It really seems that you are very educated...and I am sorry to emphasise this point.

You will know this anyway, BMR has been calculated for a reason as our basic metabolic rate, this has been calculated scientifically, whether it is up to date I do not know?

Starvation mode is a little more hard to define, I am not aware of any hard facts in this century that it does exist?

But as I said in a previous post, if you eat below your BMR then you are depriving your `organism` generally of nutrients that it needs to `survive` in a healthy fashion.
[/quote]
************
I must respectfully disagree here. It is quite possible to eat below BMR and maintain nutrition. I do it every day.

cavellj

Your body won't start to break down muscle until it's used all it's fat reserves. Which is why we have fat reserves and not muscle reserves. Where do you ppl learn this stuff?? The fact is, you don't store certain vitamins and minerals that your body needs to run, the same way you reserve energy. For example, potassium is not an energy source, but you need it in order to keep your heart pumping and nerves firing- See Terri Schivo for a real life example of what happens when you stop eating. Eating 1200 calories per day is the least you should eat without medical supervision. Anything less, you need to be monitored by a physician to make sure you're getting the foods you need to survive (plus th eonly ppl who should be put on very low calorie diets are thsoe with severe and immediate health issues related to their weight). Plus, why would you eat anything less than your BMR?? You're venturing into starving yourself mode, and that's not part of a healthy lifestyle. You will start to become irritable and cranky in addition to the physiological problems like headaches, stomach cramps and constipation...And in the end, you will either over-eat or make yourself sick from starving. Either way is not a good idea.

twinketta

Twinketta is right about losing your Lean Body Mass too. You will lose muscle, a lot more than you want to. That is another problem with radical cutting diets.

You will lose lean muscle mass if you do extreme cardio and eat over your BMR too.

hmm!! elaborate on that one???

The point is even if you are eating at your BMR or higher you will lose lean muscle mass if you do not do resistance training to maintain that muscle.

I have maintained my lean muscle mass for 4 months now while eating under my BMR under the care of my dietician. Previous to that I was eating above my bmr doing lots of walking and still losing lean muscle mass.

Edited to say: I have another 13 kilos to lose, that's a lot of fat stores right there.

Well done to you for keeping up with the work from your dietician x

I don`t want to seem pedantic, but walking is not extreme cardio? I agree wholeheartedly that resistance/muscle training is a big factor and you can take your bmr into the quotation?

twinketta

It really seems that you are very educated...and I am sorry to emphasise this point.

You will know this anyway, BMR has been calculated for a reason as our basic metabolic rate, this has been calculated scientifically, whether it is up to date I do not know?

Starvation mode is a little more hard to define, I am not aware of any hard facts in this century that it does exist?

But as I said in a previous post, if you eat below your BMR then you are depriving your `organism` generally of nutrients that it needs to `survive` in a healthy fashion.
[/quote]
************
I must respectfully disagree here. It is quite possible to eat below BMR and maintain nutrition. I do it every day.
[/quote]

With respect can you open your diary and show me how you do that everyday???

cwolfman13

BMR is a medical term, not something someone on MFP made up. Your estimated BMR is in fact what they would feed you in the hospital in a coma...which is why the coma comment comes up. Generally speaking, health care professionals, dietitians, and nutritionists do not recommend having a net calorie intake below your BMR unless you have a substantial amount of weight to lose as it can be dangerous...particularly when you're talking about people with 5 or 10 cosmetic Lbs to lose and completely crashing their diets. Having a VLCD prescribed by a Dr. and monitored by a Dr. is a far cry different thing than some random person with 20 Lbs to lose netting 500 calories per day. Really, there's no reason to net below your BMR on any consistent basis without being under the supervision of a health care professional.

Individuals with a substantial amount of weight to lose can get by eating below BMR with few side effects for longer because they have substantial fat stores to burn. Your body is a smart machine...it knows the difference between having 30-40 Lbs of fat reserve to say 200-300 Lbs of fat storage reserve. Your body is going to treat that deficit differently depending on how much you have to lose.

Personally, I think it's really only an issue with people with very drastically low calorie intakes...like having a 1,200 calorie goal and then exercising and netting to 500 or 600 calories. That's just plain unhealthy and completely unsustainable. I'm not so worried about myself occasionally dipping a couple of calories below my BMR or something though...it is an estimate. It's the folks with a BMR of 1,300 or 1,400, but netting 500 that scare the **** out of me. Basically all they are doing is developing an eating disorder (anorexia) at that point.

Mads1997

Twinketta is right about losing your Lean Body Mass too. You will lose muscle, a lot more than you want to. That is another problem with radical cutting diets.

You will lose lean muscle mass if you do extreme cardio and eat over your BMR too.

hmm!! elaborate on that one???

The point is even if you are eating at your BMR or higher you will lose lean muscle mass if you do not do resistance training to maintain that muscle.

I have maintained my lean muscle mass for 4 months now while eating under my BMR under the care of my dietician. Previous to that I was eating above my bmr doing lots of walking and still losing lean muscle mass.

Edited to say: I have another 13 kilos to lose, that's a lot of fat stores right there.

Well done to you for keeping up with the work from your dietician x

I don`t want to seem pedantic, but walking is not extreme cardio? I agree wholeheartedly that resistance/muscle training is a big factor and you can take your bmr into the quotation?

Yes you are being pedantic.