How long can you eat under BMR before damage?

First, I'm talking about a little under your BMR (say 1500 calories when your BMR is 1600). I'm not talking about huge deficits.

Second, I'm not proposing this as a weight loss solution or asking if it's cool if I do this! I'm just realizing that with my activity so much reduced by my current situation with work, I've been eating less to maintain the deficit and I'm drifting under BMR more days than I'm not.

I'm making a concerted effort to get my activity levels back where they should be, but I wanted to know if I should just plan on reducing the deficit until this situation resolves or if it won't matter for a couple of weeks if I am under BMR.

Replies

  • deksgrl
    deksgrl Posts: 7,237 Member
    It probably depends a lot on your body fat %. Somebody who has less body fat is likely to run into trouble sooner than someone with extra fat stores. Since you are only talking a few weeks, I would say don't worry about it. However, as someone who is only about 20 pounds from goal, it seems that you shouldn't have to eat below BMR to continue to lose weight, even if your activity is less. You will just be losing a little less, perhaps half a pound a week instead of a pound a week.
  • heybales
    heybales Posts: 18,842 Member
    Since you aren't in a lab study with all kinds of tests and measurements, and bi-weekly followups, and close monitoring of intake, ect, just depends.

    Likely your BMR estimate is inflated anyway, so not really eating under.

    The BMR is merely a line in the sand you might say without having all that lab stuff done, a safety line to hopefully not cause the body to adapt to a slower maintenance, removing some of the deficit you had, and making it more difficult to lose.

    But are you sure you want to maintain a bigger deficit when not exercising - that's asking for muscle mass loss.
    Only 23 lbs to go, I'm guessing you have your deficit too high anyway, should be 1 lb weekly at this point.
  • easjer
    easjer Posts: 219 Member
    My goal is misleading.

    That is to my first goal - which is 285 lbs. My ultimate goal would be a total loss of about 150 lbs.

    So, yeah. Plenty of room to work with (and my BMR isn't 1600 - that was a number I threw out. It's currently about ~2100. On a normal activity day, I burn about 3100, so deficit is easy. Right now, I barely leave my desk to refill my water bottle and pee and my activity is drastically reduced and my energy levels are much lower because I am so stressed out that all I want to do at home is sleep).

    eta - thanks for the responses! Very helpful.
  • kamac413
    kamac413 Posts: 6 Member
    Your BMR, or Basal Metabolic Rate, is the amount of calories your body needs to carry out it's basic functions from day to day (keep in mind that the calculations to determine BMR are based on averages and your personal BMR could be higher or lower than that actual number). You will burn off those calories (in your case 1600 calories) EVEN if you do absolutely nothing but lay in bed all day.

    When you chose to go below your BMR you are actually defeating your purpose (aka. to lose body fat). Your body isn't designed to give up fat when it is under stress. It is designed to store it in times of trouble because it is unsure whether or not you will "feed" it again and fat storage happens. What your body will do is eat your muscles instead which will cause a reduction of weight at the scale but not a reduction in body fat. The ultimate outcome of that long term is a smaller flabbier version of yourself. I'm fairly certain no one wants that.
  • deksgrl
    deksgrl Posts: 7,237 Member
    Since you have that much to still lose, then eating under BMR is fine.
  • deksgrl
    deksgrl Posts: 7,237 Member
    Your BMR, or Basal Metabolic Rate, is the amount of calories your body needs to carry out it's basic functions from day to day (keep in mind that the calculations to determine BMR are based on averages and your personal BMR could be higher or lower than that actual number). You will burn off those calories (in your case 1600 calories) EVEN if you do absolutely nothing but lay in bed all day.

    When you chose to go below your BMR you are actually defeating your purpose (aka. to lose body fat). Your body isn't designed to give up fat when it is under stress. It is designed to store it in times of trouble because it is unsure whether or not you will "feed" it again and fat storage happens. What your body will do is eat your muscles instead which will cause a reduction of weight at the scale but not a reduction in body fat. The ultimate outcome of that long term is a smaller flabbier version of yourself. I'm fairly certain no one wants that.

    She has a significant amount of weight to lose still, AND she is only talking about a few weeks. It is safe in those circumstances.
  • euronorris
    euronorris Posts: 211 Member
    I know it sounds counter intuitive when you are stressed out, but physical exertion will really help you deal with it. Doesn't have to be super active either, just doing some walking will help. It will also get you out in the fresh air, and give you some 'me' time to just clear your head. You can gradually increase the distance and/or speed over time too.

    I power walk to and from work now, and I REALLY value that time to myself.
  • easjer
    easjer Posts: 219 Member
    Your BMR, or Basal Metabolic Rate, is the amount of calories your body needs to carry out it's basic functions from day to day (keep in mind that the calculations to determine BMR are based on averages and your personal BMR could be higher or lower than that actual number). You will burn off those calories (in your case 1600 calories) EVEN if you do absolutely nothing but lay in bed all day.

    When you chose to go below your BMR you are actually defeating your purpose (aka. to lose body fat). Your body isn't designed to give up fat when it is under stress. It is designed to store it in times of trouble because it is unsure whether or not you will "feed" it again and fat storage happens. What your body will do is eat your muscles instead which will cause a reduction of weight at the scale but not a reduction in body fat. The ultimate outcome of that long term is a smaller flabbier version of yourself. I'm fairly certain no one wants that.

    Right, I understand all of that. But that's my question - how long does it take to get that point, and how far under do you have to be?

    It sounds like I'm probably not actually under to the point I need to be concerned. This has been going on for two weeks, and will likely be another month before my work situation allows me to leave my desk again. So it's not a forever thing, but I didn't know if I was seriously looking at damage in 4-6 weeks time, and should just adjust my deficit and loss expectations right now or whether it's not a big deal for this particular situation.
  • janicelo1971
    janicelo1971 Posts: 823 Member
    First, I'm talking about a little under your BMR (say 1500 calories when your BMR is 1600). I'm not talking about huge deficits.

    Second, I'm not proposing this as a weight loss solution or asking if it's cool if I do this! I'm just realizing that with my activity so much reduced by my current situation with work, I've been eating less to maintain the deficit and I'm drifting under BMR more days than I'm not.

    I'm making a concerted effort to get my activity levels back where they should be, but I wanted to know if I should just plan on reducing the deficit until this situation resolves or if it won't matter for a couple of weeks if I am under BMR.

    Your fine! the less you exercise the less you need to fuel your body anyway..on days I don't exercise I eat 1225 which is under by BMR also...
  • cwolfman13
    cwolfman13 Posts: 41,865 Member
    It depends on how fat you are. An obese individual can sustain that for longer as they have the fat stores necessary to make up the energy difference with very large calorie deficits. Someone leanish like myself would start seeing problems very quickly as I simply don't have the fat stores to cover such a deficit...I would very soon start burning up a lot of muscle as my body makes efforts to be more efficient with what energy it is getting...also in the effort for greater efficiency, my body would start shutting down such non-essential functions like growing hair and/or keeping the hair I have (i.e. my hair would start falling out). My finger and toe nails would start to become brittle and yellow, etc.
  • easjer
    easjer Posts: 219 Member
    I know it sounds counter intuitive when you are stressed out, but physical exertion will really help you deal with it. Doesn't have to be super active either, just doing some walking will help. It will also get you out in the fresh air, and give you some 'me' time to just clear your head. You can gradually increase the distance and/or speed over time too.

    I power walk to and from work now, and I REALLY value that time to myself.

    That is what I was doing at work, which isn't an option now. I don't work out until I get home, about 9:00 in the evening. I am still working out 3-4x per week, but my actual activity level is reduced about 50% because I can't leave my desk. A month ago, I averaged 5000 steps a day at work. I'm averaging 2500 now, and that's includes a coffee break, so some days are even lower.

    Just until I get new hires. Just until I get new hires. Just until I get new hires. . . .
  • nomeejerome
    nomeejerome Posts: 2,616 Member
    Considering the BMR & TDEE calculators are estimates, there is a chance you may not actually be netting under your BMR.
  • I sent a private message
  • RobsGirl_lds
    RobsGirl_lds Posts: 211 Member
    Obese people are sometimes given under BMR diets for up to 12 weeks I believe.
  • deksgrl
    deksgrl Posts: 7,237 Member
    You are fine, don't stress. :)
  • jdb3388
    jdb3388 Posts: 239 Member
    It's not going to hurt you for a very very long time. You are actually a candidate for a higher deficit than the suggested 1000 calories. But those diets are usually done under supervision of someone who knows what they are doing. In other words, being a few hundred under, not gonna hurt you at all.