Why shouldn't you eat under your BMR?

My BMR, set to sedentary ((which most of the time I'm not) is 1589 cals a day. I've been eating 1200 and not losing although I think that is due to quitting smoking. I remember someone saying it isn't a good idea to eat below your BMR. Just wondering, why is that? Thanks to anyone that can help!
«13

Replies

  • kittykat22459
    kittykat22459 Posts: 11 Member
    you have to eat below your bmr in order to lose weight...you doing the right thing by eatig 1200 the only reason why your not seeing any results yet is because ur deficit of calories is so small... it takes 3,500 calories to make a pound so it is just taking longer for u to see results cuz its taking alot time for ur deficit to equal 3,500 calories. normally you eat 500-1,000 calories less a day to lose 1-2 lbs a week but you cant eat less then 1200 calories a day other wise your body goes into starvation mode.
  • ril0riley
    ril0riley Posts: 54 Member
    Your BMR is what your body requires to function

    Don't eat less than what your body requires to function
  • Thankyou, it makes a lot more sense now!
  • ladynocturne
    ladynocturne Posts: 865 Member
    Sorry kittykat, but it's not true at all that you have to eat below your BMR to lose weight.

    The reason why it's recommended to NOT eat below your BMR is because this is the bare minimum your body needs to do basic functioning.

    Your brain is one of those things that does basic functioning. Your brain is unable to convert your fat stores into energy. Your brain will convert your lean muscle mass into energy. Once you do this long enough, you will lose a significant amount of lean muscle mass.

    Why is lean muscle mass important? It increases your metabolism, over all, even without exercise. It also makes you look a whole lot better, ever heard of skinnyfat? That is what happens when people diet too far under their BMRs for too long, they "lose weight" but not all of it is body fat.
  • howardheilweil
    howardheilweil Posts: 604 Member
    you have to eat below your bmr in order to lose weight...you doing the right thing by eatig 1200 the only reason why your not seeing any results yet is because ur deficit of calories is so small... it takes 3,500 calories to make a pound so it is just taking longer for u to see results cuz its taking alot time for ur deficit to equal 3,500 calories. normally you eat 500-1,000 calories less a day to lose 1-2 lbs a week but you cant eat less then 1200 calories a day other wise your body goes into starvation mode.
    This is all pretty much wrong.
  • RGv2
    RGv2 Posts: 5,789 Member
    you have to eat below your bmr in order to lose weight...you doing the right thing by eatig 1200 the only reason why your not seeing any results yet is because ur deficit of calories is so small... it takes 3,500 calories to make a pound so it is just taking longer for u to see results cuz its taking alot time for ur deficit to equal 3,500 calories. normally you eat 500-1,000 calories less a day to lose 1-2 lbs a week but you cant eat less then 1200 calories a day other wise your body goes into starvation mode.

    workaholics-no.gif

    You are confusing BMR with TDEE....for starters.
  • ril0riley
    ril0riley Posts: 54 Member
    The longer answer is that you should never eat below your BMR, since this is the baseline of what you need just to stay alive with functioning organs

    But to your actual question, "why am I not losing weight doing what I'm doing", the answer could be: you've estimated your BMR wrong, you've estimated your caloric intake/expenditure wrong, or you're in some other way over- or under-estimating.

    As another thread has pointed out, all of that is kind of moot anyway. Whatever is throwing your calculations off, if your scale and measurements aren't moving, eat a little less, move a little more, and see where that gets you.
  • Mokey41
    Mokey41 Posts: 5,769 Member
    you have to eat below your bmr in order to lose weight...you doing the right thing by eatig 1200 the only reason why your not seeing any results yet is because ur deficit of calories is so small... it takes 3,500 calories to make a pound so it is just taking longer for u to see results cuz its taking alot time for ur deficit to equal 3,500 calories. normally you eat 500-1,000 calories less a day to lose 1-2 lbs a week but you cant eat less then 1200 calories a day other wise your body goes into starvation mode.

    Whoa, that is so much bad information in one place it's not even funny!

    Your BMR is what your body would need to survive in a coma. You generally need to eat above that unless you are morbidly obese because those calculators are made using the averages of average sized people. When you get way off on either side of average the numbers start to get skewed because there isn't that assumed ratio of lean body mass to fat anymore so it is possible for an obese person to eat under their calculated BMR safely. The only way to really know your BMR is to have it medically tested which isn't feasible for most people.
  • Holly_Roman_Empire
    Holly_Roman_Empire Posts: 4,440 Member
    Bump...because I'd like some real answers.

    I was once told (can't remember the person's name on here, unfortunately), that eating under your BMR for weight loss is not unhealthy if it's temporary. I believe the reason he said it was because your BMR is the calories it takes for your body to function, but for weight loss, if you eat less than BMR, your body can use fat reserves for fuel. If you are at your goal weight, however, it makes sense that you would not want to eat below BMR because your body would be using your muscles or other source to fuel itself, hence losing weight when you don't want to.

    I'd like somebody to confirm or dispute this because I'm not sure if it's right, either.
  • you have to eat below your bmr in order to lose weight...you doing the right thing by eatig 1200 the only reason why your not seeing any results yet is because ur deficit of calories is so small... it takes 3,500 calories to make a pound so it is just taking longer for u to see results cuz its taking alot time for ur deficit to equal 3,500 calories. normally you eat 500-1,000 calories less a day to lose 1-2 lbs a week but you cant eat less then 1200 calories a day other wise your body goes into starvation mode.

    This is all wrong.
  • brraanndi
    brraanndi Posts: 325 Member
    Please disregard what Kittykat said. TDEE is different from BMR.
  • Mokey41
    Mokey41 Posts: 5,769 Member
    Directly to the OP, you haven't been at this long, you've made a lot of posts looking for quicker ways to lose and for the amount of time you've been here I'm not sure what you are expecting to have happened. Set yourself a reasonable budget, stick to it religiously, weigh/measure everything and give it some time.
  • _EndGame_
    _EndGame_ Posts: 770 Member
    Clearly KittyKat has no idea what she is talking about.

    Why would someone dish out that kind of potentially damaging advice?
  • sullus
    sullus Posts: 2,839 Member
    ...
    Your brain is one of those things that does basic functioning. Your brain is unable to convert your fat stores into energy. Your brain will convert your lean muscle mass into energy. Once you do this long enough, you will lose a significant amount of lean muscle mass.
    ...

    lolwut?
  • Colorfan
    Colorfan Posts: 230 Member
    Bump...because I'd like some real answers.

    I was once told (can't remember the person's name on here, unfortunately), that eating under your BMR for weight loss is not unhealthy if it's temporary. I believe the reason he said it was because your BMR is the calories it takes for your body to function, but for weight loss, if you eat less than BMR, your body can use fat reserves for fuel. If you are at your goal weight, however, it makes sense that you would not want to eat below BMR because your body would be using your muscles or other source to fuel itself, hence losing weight when you don't want to.

    I'd like somebody to confirm or dispute this because I'm not sure if it's right, either.

    Thats only if your doctor recommends you doing so and are constantly checking up with your doctor. For example, people who are extremely obese (and are in danger because of it) may be put on such a diet for sakes of getting them down to healthier weight.

    If you eat less than your BMR your body burns not only fat for fuel, but muscle. There is the problem, because you do not want to lose muscle. You lose muscle, and your BMR drops even lower.

    It seems a lot of people are confusing TDEE with BMR. BRM = Base Metabolic Rate, is the bare minimum your body at your weight needs in order to function. This would be the calories burned if you lay in bed for 24 hours. You eat less than this and your body begins to deteriorate.

    TDEE = Total Daily Energy Expenditure, is the average calories your body uses with all your daily activities - going to work, taking a shower, making dinner, walking to the store, etc. Here you can cut your calories a bit and have a healthy weight loss.
  • YesIAm17
    YesIAm17 Posts: 817 Member
    like 99% of what has been said in this thread so far

    what-no-gif.gif

    There is no logic or science behind the "don't go below BMR ever" idea. A deficit is a deficit and will cause your body to tap into fat stores for the energy it needs. In any deficit you may also lose some muslce but getting your macros right and strength training will help minimize this.

    As long as you get your required macros and micros there is no scientific evidence, anywhere, as far as I am aware, that something bad will automatically and always happen if you go below BMR.

    I recommend using the calculators on iifym.com to determine your Sedentary TDEE (and eat at a 10% to 30% deficit of that depending how much and how fast you want to lose, and eat back your exercise calories) and use their calculator to determine what your macros need to be.

    For those who insist that something bad will happen if you go below BMR please provide a credible source as if such exists I really would like to know. So far I've yet to see a source produced when this topic comes up on the forums. I'm always learning.
  • rick3003
    rick3003 Posts: 1 Member
    your body requires xx calories a day to function which also includes burning calories. When you eat under the BMR you risk entering what is known as starvation mode when this happens your body senses it and "shuts down" all non essential activity which also includes burning calories. Strange as it sounds you do need to eat to lose weight I've been on the program for 3 months working out for 1 hour 2-3 days a week (an elliptical) and following the programs recommended calories as closely as possible and drinking a lot of water and I have lost 22 pounds so it will work just be diligent particularly with the calorie counting. Remember it doesn't help to cheat the calorie count you are only fooling yourself
  • Mokey41
    Mokey41 Posts: 5,769 Member
    your body requires xx calories a day to function which also includes burning calories. When you eat under the BMR you risk entering what is known as starvation mode when this happens your body senses it and "shuts down" all non essential activity which also includes burning calories. Strange as it sounds you do need to eat to lose weight I've been on the program for 3 months working out for 1 hour 2-3 days a week (an elliptical) and following the programs recommended calories as closely as possible and drinking a lot of water and I have lost 22 pounds so it will work just be diligent particularly with the calorie counting. Remember it doesn't help to cheat the calorie count you are only fooling yourself

    Did you read any of the rest of this thread? Forget starvation mode but kudos for a strong first post.
  • brower47
    brower47 Posts: 16,356 Member
    Your BMR is what your body requires to function

    Don't eat less than what your body requires to function

    This.

    Basal Metabolic Rate (BMR) is the rate at which the body uses calories if you do not move at all, aka bedridden. If you eat at BMR, you will lose weight assuming you aren't bedridden. Eating less runs the risk of your body using a disproportionately high amount of lean muscle mass for energy. The result, less weight but with a relatively depressed metabolism (you have to eat less to maintain) and a higher body fat percentage (a flabbier appearance despite a lower weight).

    If you're eating as little as you claim then you'd be in the 'losing weight too fast" category. If you're not losing weight at the calories you're logging, then you're likely underestimating your intake. Weigh and measure everything for an accurate count and take out the guesswork thereby allowing you to actually reach your goal.

    Good luck.
  • Serah87
    Serah87 Posts: 5,481 Member
    you have to eat below your bmr in order to lose weight...you doing the right thing by eatig 1200 the only reason why your not seeing any results yet is because ur deficit of calories is so small... it takes 3,500 calories to make a pound so it is just taking longer for u to see results cuz its taking alot time for ur deficit to equal 3,500 calories. normally you eat 500-1,000 calories less a day to lose 1-2 lbs a week but you cant eat less then 1200 calories a day other wise your body goes into starvation mode.

    NO!!!!!
  • AccioFitness
    AccioFitness Posts: 244 Member
    you have to eat below your bmr in order to lose weight...you doing the right thing by eatig 1200 the only reason why your not seeing any results yet is because ur deficit of calories is so small... it takes 3,500 calories to make a pound so it is just taking longer for u to see results cuz its taking alot time for ur deficit to equal 3,500 calories. normally you eat 500-1,000 calories less a day to lose 1-2 lbs a week but you cant eat less then 1200 calories a day other wise your body goes into starvation mode.

    NOPE.

    OP, please ignore this "advice", it is horribly, outrageously wrong. Your BMR is the amount of calories your body needs at rest. As in, if you were comatose you would need to be taking in that amount to keep your body functioning. Eating below it, especially for long periods of time, is not intelligent.

    Our bodies are wired for feast vs. famine. If we are not taking in adequate calories our body will assume it's a time of famine and hold on to as much as it can. It will eat muscle first and then fat stores, which means all these people who are eating 500+ below their BMR are not losing fat, they are losing muscle. And generally when you start eating normally again your body will cling to those extra calories because it still thinks it's in a time of famine, which is why so many people gain everything back plus some following a low-cal diet.

    When a person wants to lose weight they do need a deficit, that is true. But not from your BMR. If should be taken from your total daily energy expenditure (TDEE), which is the amount of calories your body needs to have daily for all your activities; like walking, cleaning, working out, etc. If you were to take 500 calories a day from your TDEE that would create a deficit of 3,500 calories a week, equivalent to about a pound. The more you move/workout the more your body generally needs. That is why we have members here eating 2,000+ calories daily and still actively losing.

    Please do your research. There are some amazing links here on MFP that are stickied to the top of the Getting Started board. Read them and learn how to stay healthy while actively losing.
  • ril0riley
    ril0riley Posts: 54 Member

    There is no logic or science behind the "don't go below BMR" idea.

    Here is a working definition of BMR for you
    Basal metabolic rate (BMR), and the closely related resting metabolic rate (RMR), is the amount of energy expended daily by humans and other animals at rest. Rest is defined as existing in a neutrally temperate environment while in the post-absorptive state. In plants, different considerations apply.

    The release, and using, of energy in this state is sufficient only for the functioning of the vital organs, the heart, lungs, nervous system, kidneys, liver, intestine, sex organs, muscles, and skin.

    If you agree with that definition, I don't see why you'd think it would be okay to eat less than what is required for minimum bodily function

    If you think that definition is somehow flawed, I'm open to hear what you think is wrong about it

    We're talking about BMR, not TDEE
  • YesIAm17
    YesIAm17 Posts: 817 Member

    There is no logic or science behind the "don't go below BMR" idea.

    Here is a working definition of BMR for you
    Basal metabolic rate (BMR), and the closely related resting metabolic rate (RMR), is the amount of energy expended daily by humans and other animals at rest. Rest is defined as existing in a neutrally temperate environment while in the post-absorptive state. In plants, different considerations apply.

    The release, and using, of energy in this state is sufficient only for the functioning of the vital organs, the heart, lungs, nervous system, kidneys, liver, intestine, sex organs, muscles, and skin.

    If you agree with that definition, I don't see why you'd think it would be okay to eat less than what is required for minimum bodily function

    If you think that definition is somehow flawed, I'm open to hear what you think is wrong about it

    We're talking about BMR, not TDEE

    Thanks, but I am well aware of the definitions and the differences.

    I still see nothing in there that suggests the needed energy would not simply be acquired from the fat you have stored.

    When you are in a deficit of TDEE the energy deficit is filled by tapping into fat stores.

    When you are in a deficit of BMR why would the deficit not also be filled by tapping into fat stores?

    I am genuinely open to any facts with credible sources that say otherwise, but the definition you pasted doesn't really speak to the question at hand or discount my statement.
  • yarwell
    yarwell Posts: 10,477 Member
    If you think that definition is somehow flawed, I'm open to hear what you think is wrong about it

    the definition is ok, it's what you do with it.

    The BMR is the largest part of the calories we expend, however it does not have to be provided from food - it can be provided from fat reserves. That's why hunger strikers take months to die, not five minutes of not eating. Geez.

    This is where the "don't eat below your BMR" chorus go wrong. Most (or at least many) clinical studies on weight loss feed people less than 1,000 calories a day, which is below pretty well anyone's BMR apart from anorexics.

    Find out about Mr AB the very very obese Scotsman, who ate nothing for over a year, lived off his fat reserves which were vastly reduced and he went on to maintain his lower weight for some time.
  • brower47
    brower47 Posts: 16,356 Member

    There is no logic or science behind the "don't go below BMR" idea.

    Here is a working definition of BMR for you
    Basal metabolic rate (BMR), and the closely related resting metabolic rate (RMR), is the amount of energy expended daily by humans and other animals at rest. Rest is defined as existing in a neutrally temperate environment while in the post-absorptive state. In plants, different considerations apply.

    The release, and using, of energy in this state is sufficient only for the functioning of the vital organs, the heart, lungs, nervous system, kidneys, liver, intestine, sex organs, muscles, and skin.

    If you agree with that definition, I don't see why you'd think it would be okay to eat less than what is required for minimum bodily function

    If you think that definition is somehow flawed, I'm open to hear what you think is wrong about it

    We're talking about BMR, not TDEE

    Thanks, but I am well aware of the definitions and the differences.

    I still see nothing in there that suggests the needed energy would not simply be acquired from the fat you have stored.

    When you are in a deficit of TDEE the energy deficit is filled by tapping into fat stores.

    When you are in a deficit of BMR why would the deficit not also be filled by tapping into fat stores?

    I am genuinely open to any facts with credible sources that say otherwise, but the definition you pasted doesn't really speak to the question at hand or discount my statement.

    It's difficult enough for most people to get the micronutrients they need for proper body function when eating below maintenance. The lower you go, the more difficult it becomes and the more time and thought is required to plan your diet accordingly. Most people don't take the time to preplan a week's worth of food in order to ensure that those micronutrient minimums are met in order to maintain proper bodily function (some of which it takes weeks to months of poor nutrition for the effects to become noticeable).

    Also, eating at such a high deficit runs the risk of the body using a disproportionate amount of muscle to fat as its energy source leaving the person with either the same body fat percentage or in some cases, an even higher % that before the weight loss took place (this is not the case in obese individuals but more for people within 50 lbs of their idea weight). Smaller deficits (especially combined with some sort of weight bearing exercise) will help to ensure that the muscle loss is minimized, leaving the individual with a lower body fat percentage once the weight is lost.

    You can and will lose weight eating below BMR but it's difficult to do in a healthy (nutrients) manner and runs the very high risk of high muscle loss.
  • YesIAm17
    YesIAm17 Posts: 817 Member
    If you think that definition is somehow flawed, I'm open to hear what you think is wrong about it

    the definition is ok, it's what you do with it.

    The BMR is the largest part of the calories we expend, however it does not have to be provided from food - it can be provided from fat reserves. That's why hunger strikers take months to die, not five minutes of not eating. Geez.

    This is where the "don't eat below your BMR" chorus go wrong. Most (or at least many) clinical studies on weight loss feed people less than 1,000 calories a day, which is below pretty well anyone's BMR apart from anorexics.

    Find out about Mr AB the very very obese Scotsman, who ate nothing for over a year, lived off his fat reserves which were vastly reduced and he went on to maintain his lower weight for some time.

    43591-THIS-gif-ECaV.gif
  • Holly_Roman_Empire
    Holly_Roman_Empire Posts: 4,440 Member
    If you think that definition is somehow flawed, I'm open to hear what you think is wrong about it

    the definition is ok, it's what you do with it.

    The BMR is the largest part of the calories we expend, however it does not have to be provided from food - it can be provided from fat reserves. That's why hunger strikers take months to die, not five minutes of not eating. Geez.

    This is where the "don't eat below your BMR" chorus go wrong. Most (or at least many) clinical studies on weight loss feed people less than 1,000 calories a day, which is below pretty well anyone's BMR apart from anorexics.

    Find out about Mr AB the very very obese Scotsman, who ate nothing for over a year, lived off his fat reserves which were vastly reduced and he went on to maintain his lower weight for some time.

    This is pretty much what I've been told too, and what my previous post was referring to. It's assumed that if you eat less than your BMR, your organs will shut down or something. Why won't your body use up the fat stores on your body?
  • ril0riley
    ril0riley Posts: 54 Member
    If you think that definition is somehow flawed, I'm open to hear what you think is wrong about it

    Find out about Mr AB the very very obese Scotsman, who ate nothing for over a year, lived off his fat reserves which were vastly reduced and he went on to maintain his lower weight for some time.

    Sorry, you mean the guy who was warned every step of the way not to starve himself by his doctors? I'm not claiming you'd go into immediate organ failure eating below BMR, I'm wondering why you would go into such a steep calorie deficit as to eat below your basic daily needs.

    A modest deficit from TDEE should be sufficient. Is anyone here operating under the assumption that OP's issue is that she isn't cutting deep enough into her BMR?