Who eats under BMR? HELP!

joejccva71

OP,

It isn't necessarily bad to eat below your BMR on the short term, however it also depends on how morbidly obese a person is. If a person is so overweight then it's fine to knock off the pounds but at some point that person would need to start eating slightly more to slow that weight loss down the more they lose.

The problem lies when people eat a drastic calorie deficit not only under their TDEE but also under their BMR like the folks that eat 500 calories a day on this HCG diet or some other quick fix.

joejccva71

To the human body, Fat is a higher priority than muscle. Fat is part of the endocrine system, it is used to create hormones to regulate body function and also to insulate and protect vital organs. Also so called "brown fat" is how the body regulates body temperature.

What this means is that over time, extended large caloric deficits will lead to the body burning muscle for energy over fat. Large caloric deficits cause the body to prioritize what gets energy and what starves. The brain and vital organs are the number one priority, including fat. Also, fat takes very little caloric energy to sustain, compared to muscle. In times of starvation (keep in mind, your body doesn't understand "dieting to lose weight" it only understands getting enough fuel vs not getting enough fuel) your body will burn off muscle in order to conserve energy.

I don't know where you heard eating under BMR causes starvation mode in 2 days, because that's absolutely false. Complete fasting will cause starvation mode in as little as 2-3 days. Eating at a severe deficit under your TDEE(not BMR) will cause starvation mode, but may take several weeks to several months to kick in, depending on the actual deficit.

Sounds like you know the fine words and wisdom of Lyle McDonald.

Silverkittycat

To the human body, Fat is a higher priority than muscle. Fat is part of the endocrine system, it is used to create hormones to regulate body function and also to insulate and protect vital organs. Also so called "brown fat" is how the body regulates body temperature.

What this means is that over time, extended large caloric deficits will lead to the body burning muscle for energy over fat. Large caloric deficits cause the body to prioritize what gets energy and what starves. The brain and vital organs are the number one priority, including fat. Also, fat takes very little caloric energy to sustain, compared to muscle. In times of starvation (keep in mind, your body doesn't understand "dieting to lose weight" it only understands getting enough fuel vs not getting enough fuel) your body will burn off muscle in order to conserve energy.

I don't know where you heard eating under BMR causes starvation mode in 2 days, because that's absolutely false. Complete fasting will cause starvation mode in as little as 2-3 days. Eating at a severe deficit under your TDEE(not BMR) will cause starvation mode, but may take several weeks to several months to kick in, depending on the actual deficit.

everyone wants to lose weight quickly by running huge deficits and then wonder what they're supposed to do when they plateau, when it would be a better idea to have a deficit around10-20% of TDEE and then lower it if you plateau. just my opinion of course

+1

tigersword

Also, to the OP, the reason you can't find any articles on eating under your BMR is because BMR is meaningless when it comes to calculating calorie deficits. Take 2 people, same height, weight, and body composition. I'll use my BMR to represent them both, which is ~2069. One of those people is extra active, which gives a TDEE (Total Daily Energy Expenditure) of 3932. Obviously, to eat under this person's BMR they would need a deficit of roughly 2000 calories, which will absolutely lead to starvation mode. (Yes, I know someone extra active most likely wouldn't need to lose weight in the first place, but these are hypotheticals after all.) Now, the second person is sedentary. That person's TDEE is 2483. To eat under BMR this person would only need a 400 calorie deficit or so. Eating a 1000 calorie deficit with more than 30 pounds of weight to lose will not lead to any ill effects.

Basically, some people can eat under BMR, and some people can't, it's just a matter of how active they are and how much weight they have to lose. BMR, in and of itself, is only useful to know to calculate your TDEE, then you set your deficit from there, and you really shouldn't have more than a 1000 calorie deficit, generally. Anymore than that and you will be losing muscle as well as fat, for reasons already stated.

NovemberJune

thanks.

Also, to the OP, the reason you can't find any articles on eating under your BMR is because BMR is meaningless when it comes to calculating calorie deficits. Take 2 people, same height, weight, and body composition. I'll use my BMR to represent them both, which is ~2069. One of those people is extra active, which gives a TDEE (Total Daily Energy Expenditure) of 3932. Obviously, to eat under this person's BMR they would need a deficit of roughly 2000 calories, which will absolutely lead to starvation mode. (Yes, I know someone extra active most likely wouldn't need to lose weight in the first place, but these are hypotheticals after all.) Now, the second person is sedentary. That person's TDEE is 2483. To eat under BMR this person would only need a 400 calorie deficit or so. Eating a 1000 calorie deficit with more than 30 pounds of weight to lose will not lead to any ill effects.

Basically, some people can eat under BMR, and some people can't, it's just a matter of how active they are and how much weight they have to lose. BMR, in and of itself, is only useful to know to calculate your TDEE, then you set your deficit from there, and you really shouldn't have more than a 1000 calorie deficit, generally. Anymore than that and you will be losing muscle as well as fat, for reasons already stated.

NovemberJune

thanks. i definitely am not interested in eating 500 calories per day! if i'm hungry i eat! i just haven't been concerning myself with making sure i eat at least my BMR anymore. i've lost 33 in 7 months, and my goal is to lose 60 by the time i hit 1 year, then lose 30 in the following year. i expect it to get harder the more i've lost.

thanks

OP,

It isn't necessarily bad to eat below your BMR on the short term, however it also depends on how morbidly obese a person is. If a person is so overweight then it's fine to knock off the pounds but at some point that person would need to start eating slightly more to slow that weight loss down the more they lose.

The problem lies when people eat a drastic calorie deficit not only under their TDEE but also under their BMR like the folks that eat 500 calories a day on this HCG diet or some other quick fix.

tigersword

It definitely gets harder the closer you get to your goal. The lower your body fat percentage, the more your body wants to cling to the fat it has, out of fear of not having enough to survive, since you are at a calorie deficit. This is why calorie deficits must get smaller and smaller as you get closer to goal, and also why you should take a week or two every few months and eat at maintenance, in order for your body to deregulate itself.

Again, your body and brain to communicate very well. You may be thinking, "gotta lose some weight," but your body just thinks, "Boy there sure is a lot less food around here suddenly, better store some fat to make sure we survive until we find more."

Feed it, and it gets the message that food isn't that scarce, and burning fat is ok.

malenahan

I love working out and am a marathon runner. My next marathon is in about a month so trying to figure out how many calories I need to eat gets very difficult at times. I typically run 50-55 miles a week which includes a long run of 16-22 miles on Saturday and I also do a lot of cross training (elliptical, ChaLean Extreme, Turbo Fire). I also eat very healthy and pretty much eat the same things all the time. How should I handle my calories after a 22 mile run? Are there any marathon runners that have these same questions? I am not trying to lose weight necessarily but just want to become leaner and stronger.

rileysowner

I ate under my BMR for the first 60-70 pounds of my weight loss. It didn't seem to negatively effect my weight loss at all. I don't do it now, but then I am no longer obese, so I am no longer trying to lose 2 pounds a week.

souki19

bump

servilia

I have eaten under my BMR since starting in late July and have lost almost 20lbs. I was not obese or even overweight either so I didn't have much to lose to begin with. I certainly didn't go into starvation mode and GAIN weight LMAO.

Erica0718

I have eaten under my BMR since starting in late July and have lost almost 20lbs. I was not obese or even overweight either so I didn't have much to lose to begin with. I certainly didn't go into starvation mode and GAIN weight LMAO.

servilia, are you eating at your BMR plus exercise calories ? I am curious because I am also 5'9 and only have 10-15 lbs to lose but I am struggling to find out what works for me. When I signed up I was at 1200 that didn't work so I went up to 1400 and lost 4lbs. Now I am stuck and my weight is fluctuating. Currently I do eat most of my exercise cals. I have my lifestyle set as sedentary because I work at a desk job but I do exercise after work and am active on the weekends. My BMR is 1507, should I eat that plus my exercise cals? Thanks you all for any help.

servilia

I have eaten under my BMR since starting in late July and have lost almost 20lbs. I was not obese or even overweight either so I didn't have much to lose to begin with. I certainly didn't go into starvation mode and GAIN weight LMAO.

servilia, are you eating at your BMR plus exercise calories ? I am curious because I am also 5'9 and only have 10-15 lbs to lose but I am struggling to find out what works for me. When I signed up I was at 1200 that didn't work so I went up to 1400 and lost 4lbs. Now I am stuck and my weight is fluctuating. Currently I do eat most of my exercise cals. I have my lifestyle set as sedentary because I work at a desk job but I do exercise after work and am active on the weekends. My BMR is 1507, should I eat that plus my exercise cals? Thanks you all for any help.

I already messages you but in case anyone else is reading - I have my goal set to 1200 and go under and over depending how hungry I am.

caly_man

this was very good reading.

when i started

weeks 1 - 6: I ate 400 kcals below my BMR (following the suggestion of MFP calc.)

on week 6, it really hit me hard, that week, i stayed at 1600 but was hungry all the time.

week 7-11: I ate 200 kcals below my BMR.

at the moment, I'm still obese, not famished, so I'm not sure If I'm going to change anything just yet.

(in order not to confuse anyone, Im a man and in the above scenarios, the total cals. were 1600 & 1800)