Why is losing weight too fast a bad thing?

Just like the title says, my question is, why is losing weight too fast a bad thing?

Obviously, I do not mean eating a dangerously low amount of calories - I know why that's unhealthy.

But let's say someone is really active. They're eating 1800 calories a day but still losing 3lbs a week. They're eating a decent amount of calories...getting necessary nutrients. Is it still not advisable to lose the 3lbs a week? Should they really look into eating more calories to slow the weight loss?
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Replies

  • LyndaBSS
    LyndaBSS Posts: 6,964 Member
    Fast weight loss is typically not sustainable weight loss.

    There's no one size fits all answer to your question. We are all unique and so our bodies will react uniquely to weight loss.
  • koalathebear
    koalathebear Posts: 236 Member
    Maybe the question can be recut. Is losing 1kg a week automatically bad/too fast or can it be safe/healthy even if you are not extremely obese?
  • lemurcat2
    lemurcat2 Posts: 7,885 Member
    Maybe the question can be recut. Is losing 1kg a week automatically bad/too fast or can it be safe/healthy even if you are not extremely obese?

    1 kg a day (2.2 lb) is not automatically bad. Losing about 1% of body weight per week is recommended. Can it be safe/healthy if you are 5'3, 135, losing vanity weight? IMO, no. That's because of math.

    Someone 35, lightly active, with those stats probably burns about 1800 per day. There's no way to cut enough to sustain a loss of 2.2 lb without it being too low.

    Yes, the person can add exercise -- say running on average 10 miles a day -- to add another 1000 cals a day, but obviously with that amount of intense exercise they will need more cals to avoid over-taxing their bodies.

    I tend to think this is more the situation being considered, and not the 440 lb man (who certainly can lose faster).

    It's not just a matter of nutrition, if you lose too fast in this case you will lose more muscle and can have negative effects on sleep, hair and nails, as well as the other things mentioned, and will likely end up with all the symptoms of overtraining, as well as potential hormone disruption, at minimum.
  • StaciMarie2020
    StaciMarie2020 Posts: 68 Member
    When you are in a caloric deficit - your body finds the needed energy elsewhere. Aiming for a slow & steady weight loss while also eating plenty of protein and doing weight training means your body will take the majority of what it needs from your fat stores, and very little from muscle. Going too fast means your body will take more from muscle. Losing muscle has negative consequences.
  • CSARdiver
    CSARdiver Posts: 6,252 Member
    Thinking of the body as a biological system - these systems adapt well under gradual changes - much better than under dramatic changes. Drastic changes result in stress - some quantifiable, some not. This is why very low calorie diets/low calorie diets require some manner of medical monitoring.


  • cmriverside
    cmriverside Posts: 34,454 Member
    kimny72 wrote: »
    What Azdak said.

    All you people disagreeing with him have been drinking the MFP Kool Aid.

    Someone who is morbidly obese would do fine on 1800. It is way more important to get that weight off as soon as possible (for the obese/morbidly obese.)

    That person has plenty of body fat to use as fuel. It's important to get good nutrition with that 1800, but it would be more than sufficient - regardless of activity level.

    I didn't disagree with Azdak. But it's possible that people are looking at OP's picture, considering the possibility that she is asking about herself, and automatically disagreeing with anything that might seem to give her permission. I'm not saying that's a good reason, mind you :wink: just thinking out loud.

    Of course. That's when reading is helpful.

    ..and then, sometimes I don't read either. :lol:

    I just think Azdak has been one of the most helpful and knowledgeable posters on MFP for many years. I tend to White Knight those people.
  • sugarismyweakness
    sugarismyweakness Posts: 30 Member
    Maybe I'm wrong, but I always thought losing weight quickly just wasn't good from an appearance point of view...

    The quicker you lose it, the less time your body has to adapt and tighten back into shape which leaves you with saggy skin. That and the fact that the faster you lose it, the quicker you put it back on.

    These two reasons are the main ones why I've always said I don't want to lose weight quickly. If I am wrong, it's still enough to keep me doing it slowly. The last thing I want is to spend years getting down to goal weight and be mortified by loose sagging skin so still hide in baggy clothes!

    So from my point of view, there are no physical health implications if you're losing weight quickly and properly, but the mental repercussions are phenomenal!
  • cmriverside
    cmriverside Posts: 34,454 Member
    Thanks, @psychod787
  • psychod787
    psychod787 Posts: 4,099 Member
    Thanks, @psychod787

    No problem. I have just spent the last 2 years researching this. Though I will add a caveat..... there are places where a body is not meant to go. Been there... living it. If I were to give the "hypothetical" person advice from my research and experience. Change your diet.... eat higher protein at the expense of carbohydrates. Hyper restrict added fats and carbohydrates. Get active... slowly work yourself up to 10000 steps a day and add a full body lifting routine 3 days a week. Not an advocate of restricting any macro nutrient honestly. We have to look at certain foods as hyper normal stimulus. It says much when a rat will endure extreme pain to get to an oreo, when regular rodent chow is freely available. Not saying oreos are "bad"... just an example.
  • cmriverside
    cmriverside Posts: 34,454 Member
    edited October 2019
    psychod787 wrote: »
    Thanks, @psychod787

    No problem. I have just spent the last 2 years researching this. Though I will add a caveat..... there are places where a body is not meant to go. Been there... living it. If I were to give the "hypothetical" person advice from my research and experience. Change your diet.... eat higher protein at the expense of carbohydrates. Hyper restrict added fats and carbohydrates. Get active... slowly work yourself up to 10000 steps a day and add a full body lifting routine 3 days a week. Not an advocate of restricting any macro nutrient honestly. We have to look at certain foods as hyper normal stimulus. It says much when a rat will endure extreme pain to get to an oreo, when regular rodent chow is freely available. Not saying oreos are "bad"... just an example.

    But your experience is/was becoming too lean. That has a lot of negative consequences which you are now trying to fix.

    Azdak's posts were clearly aimed at people with too much body fat. 1800 calories would have worked for you at the beginning of your weight loss when you had 200 pounds to lose.

    At the lower end (say, closer to 25 BMI) - yeah, get those numbers dialed in so you are fueling any additional activity by eating adequate/enough food. Hopefully once someone is nearing a healthy body fat amount, they have addressed the numbers. I am ONLY referring to obese or morbidly obese people.

    The OP doesn't give us much to go on, and therefore some threads (like this one) are speaking "In General" to anyone reading. It's all we can do, really, until and unless she gives us more info.

  • psychod787
    psychod787 Posts: 4,099 Member
    psychod787 wrote: »
    Thanks, @psychod787

    No problem. I have just spent the last 2 years researching this. Though I will add a caveat..... there are places where a body is not meant to go. Been there... living it. If I were to give the "hypothetical" person advice from my research and experience. Change your diet.... eat higher protein at the expense of carbohydrates. Hyper restrict added fats and carbohydrates. Get active... slowly work yourself up to 10000 steps a day and add a full body lifting routine 3 days a week. Not an advocate of restricting any macro nutrient honestly. We have to look at certain foods as hyper normal stimulus. It says much when a rat will endure extreme pain to get to an oreo, when regular rodent chow is freely available. Not saying oreos are "bad"... just an example.

    But your experience is/was becoming too lean. That has a lot of negative consequences which you are now trying to fix.

    Azdak's posts were clearly aimed at people with too much body fat. 1800 calories would have worked for you at the beginning of your weight loss when you had 200 pounds to lose.

    At the lower end (say, closer to 25 BMI) - yeah, get those numbers dialed in so you are fueling any additional activity by eating adequate/enough food. Hopefully once someone is nearing a healthy body fat amount, they have addressed the numbers. I am ONLY referring to obese or morbidly obese people.

    The OP doesn't give us much to go on, and therefore some threads (like this one) are speaking "In General" to anyone reading. It's all we can do, really, until and unless she gives us more info.

    Oh, yes ma'am I agree. If you need faster initial weight loss 1800 cals are ok. My point is, when a grossly obese individual is put on a diet as discussed, restricting to 1800 calories MAY not be necessary. The brain and body might restrict to LESS. Shown in blander diet studies. So my thought is... change your diet and lifestyle and let the chips fall where they may. If one day your body wants 1500 and the next ot wants 2100... it all comes out on the wash. I THINK the body has a strange way of reducing its weight when switching from a SAD diet to one more of a way our ancestors ate. Not touting "paleo", they have a lot wrong, but with less processed/energy dense foods on general.
  • psychod787
    psychod787 Posts: 4,099 Member
    psychod787 wrote: »
    Thanks, @psychod787

    No problem. I have just spent the last 2 years researching this. Though I will add a caveat..... there are places where a body is not meant to go. Been there... living it. If I were to give the "hypothetical" person advice from my research and experience. Change your diet.... eat higher protein at the expense of carbohydrates. Hyper restrict added fats and carbohydrates. Get active... slowly work yourself up to 10000 steps a day and add a full body lifting routine 3 days a week. Not an advocate of restricting any macro nutrient honestly. We have to look at certain foods as hyper normal stimulus. It says much when a rat will endure extreme pain to get to an oreo, when regular rodent chow is freely available. Not saying oreos are "bad"... just an example.

    But your experience is/was becoming too lean. That has a lot of negative consequences which you are now trying to fix.

    Azdak's posts were clearly aimed at people with too much body fat. 1800 calories would have worked for you at the beginning of your weight loss when you had 200 pounds to lose.

    At the lower end (say, closer to 25 BMI) - yeah, get those numbers dialed in so you are fueling any additional activity by eating adequate/enough food. Hopefully once someone is nearing a healthy body fat amount, they have addressed the numbers. I am ONLY referring to obese or morbidly obese people.

    The OP doesn't give us much to go on, and therefore some threads (like this one) are speaking "In General" to anyone reading. It's all we can do, really, until and unless she gives us more info.

    I would also like to make a statement about the BMI. While bmi CAN be a good indicator of health, in a grossly obese person i THINK it's worth less. If someone goes from 400 to 250lbs, the bmi says they are still obese, but related health markers will be vastly improved. Many may struggle to get to a "healthy" bmi. That COULD be a reason why they may say frack it! If I cant get to what a chart says is healthy, then why bother. One must look at where they have been to where they are IMHO...
  • BasedGawd412
    BasedGawd412 Posts: 346 Member
    Just like the title says, my question is, why is losing weight too fast a bad thing?

    Obviously, I do not mean eating a dangerously low amount of calories - I know why that's unhealthy.

    But let's say someone is really active. They're eating 1800 calories a day but still losing 3lbs a week. They're eating a decent amount of calories...getting necessary nutrients. Is it still not advisable to lose the 3lbs a week? Should they really look into eating more calories to slow the weight loss?

    Some people just love regurgitating *kitten* they read online without experiencing it themselves.

  • psychod787
    psychod787 Posts: 4,099 Member
    Just like the title says, my question is, why is losing weight too fast a bad thing?

    Obviously, I do not mean eating a dangerously low amount of calories - I know why that's unhealthy.

    But let's say someone is really active. They're eating 1800 calories a day but still losing 3lbs a week. They're eating a decent amount of calories...getting necessary nutrients. Is it still not advisable to lose the 3lbs a week? Should they really look into eating more calories to slow the weight loss?

    Some people just love regurgitating *kitten* they read online without experiencing it themselves.

    I still say its a matter of context. If someone switches their diet and there body only wants 1800 cals a day and they lose 3 lbs a week. Ok, but if one is consciously restricting to 1800 cals a day and they are having complications. Then it's not ok. Context matters.. as far as people just having verbal "diarrhea" from stuff they just read? Well, some of us live what we say...
  • magnusthenerd
    magnusthenerd Posts: 1,207 Member
    Given the caveats that OP never specified at what weight...
    Seems like for women there can be too high a TDEE, let alone deficit in proportion to body fat level. I'm unsure of how it scales, but even just using a lot of energy relative to leanness can cause amenorrhoea. Kind of hard to know if it scales because there probably aren't too many if any women out there in the obese weight category that are also getting TDEEs into a say above 7,000 calorie range.