Letting go of the “ideal” body weight

Read through the research literature on eating disorders–especially anorexia–and you won’t be able to avoid the phrase “ideal body weight.” Weights are expressed as “% IBW.” Treatment is measured as to whether sufferers are able to return to 85%, 90% or 95% (pick one) of “ideal body weight.”

It’s a phrase I seriously hate.

In many of these studies, the researchers calculate ideal body weight as the 50th percentile BMI-for-age in adolescents and/or healthy weight charts from the health insurance industry. That are generally 50 years old. They are also frequently used as estimates for weight goals when treating patients.  Hey, they’re supposed to be “ideal,” right?

Here’s the thing: the 50th percentile for weight or BMI is only “ideal” for the one percent of the population that happens to naturally fall along that percentile. For others, it’s either an over- or underestimate of weight. I understand that there’s quite a lot of guesswork when it comes to setting appropriate weight restoration goals for a person, and the 50th percentile is probably not a bad place to start for lack of other data BUT can we at least admit that it’s a guess and not some sort of ideal?

Then there’s the ideal body weight. A singular weight. It’s stupid. A woman’s weight can vary by 5-10 pounds during her menstrual cycle. Been there, done that, got the t-shirt (and baggy sweatpants).* Our weight can also vary by our hydration status, time of year, and any number of things. When I was in treatment for the second time, I was given a target weight that was X.5 pounds. Seriously? I thought it was the people with eating disorders who were ridiculously uptight and precise about body weights.

Lastly, when you’re dealing with something like ideal body weight, there’s the thorny issue of “ideal”. Exactly whose ideal are we talking about? Cultural ideals? That strikes me as silly. Health ideals? Maybe, but, again, there appears to be a fairly wide range of body weights at which someone is at “ideal” health.

Some treatment professionals had actually set my target weight by asking me what I wanted to weigh. Asking someone who just carved “pig” into her stomach with a razor blade what she thought her ideal weight was strikes me as peculiarly short-sighted.

Other professionals determined my “ideal” weight using the formula that said the “ideal” weight for woman is 100 pounds for five feet and 5 pounds for each additional inch. Certainly there are some people for whom that is accurate, but it isn’t for me and a lot of people I know.

I spent years during my illness at weights the broader culture deemed ideal and at weights treatment professionals thought were ideal (news flash: it’s generally not healthy for a grown woman to weigh what she did when she was 12, yet no one ever objected or even thought it was a problem. No, I wasn’t a scrawny 12-year-old, but still…). The problem is that the  idea of ideal body weights come with a hella lot of cultural baggage. So many ED professionals talk up how bodies can be healthy at many different sizes, that our current cultural obsession with obesity isn’t doing anyone any good, yet they routinely calculate ideal body weights for people with anorexia as being ludicrously low. You can’t get away from the obesity phobia.

So if we’re not going to use “ideal” body weights, what’s the alternative? Target weights? Maybe, but for adolescents, targets aren’t stationary.  I think we need to let go of these ideals and targets and focus more on weights that are biologically appropriate for each patient. Some people are tall and lean, others are shorter and stockier. Each person will have a weight range that is biologically appropriate for them. It’s not about ideals or judgements or targets or whatever. It’s just reality.

We need to let go of the idea that all people with anorexia are going to have weights that naturally tend towards the lower end of the “normal” BMI spectrum. We need to stop assuming that “not underweight” means that a person is at a weight that is appropriate for them. We need to be aware that some people have biologically appropriate weights that are even above BMI 25. And that’s okay.

In a world of 7 billion people, there isn’t an ideal body weight. It varies. And the sooner we accept that, the better we’ll all be.


*One of the benefits of aging: the weight fluctuations and other physical symptoms have greatly evened out over the years. I’m certainly not free of PMS by a long shot (the emotional symptoms are still awful), but the physical stuff isn’t quite as bad.

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44 Responses to “Letting go of the “ideal” body weight”

  1. Possibly one of the most observant brilliant articles you’ve written. I found myself nodding in agreement ….empathizing big-time…

    I am entirely FRUSTRATED with doctors somehow “expecting” me to stabilize with the lower realm of a healthy weight…because of my long-standing..older “age” anorexia.

    I let out audible chuckles with “…researchers calculate ideal body weight as the 50th percentile BMI- for-age in adolescents and/or healthy weight charts from the health insurance industry. That are generally 50 years old.”….and “no, I wasn’t a scrawny 12 year-old, but still…”

    Thank you for your astute observations!

    • It is SO frustrating, especially when your target weight is significantly less than what you weighed before the AN started. It just told me that I was right to start starving myself, that I was the disgusting fat horrible awful pig that I thought I was.

      Then, when your body stabilizes at a weight that is significantly higher than what anyone told you, you feel like utter CRAP because you got “too fat.” The reality is that I probably didn’t, but I sure as hell feels that way!

      I am trying to accept my biologically appropriate weight, and mostly I do okay, but it still really sucks sasquatch balls sometimes. Alas…

      Glad you found the post helpful/useful.

  2. Your story about the second time you were in treatment reminds me of the time a vet told my parents that our dog “could stand to lose half a pound.” It sounded ridiculous even for a 60lb labrador retriever! But seriously – a target weight (for a human!) to the half-pound?!?! Oh my god, I can’t even.

    I suppose I can understand setting an initial low target weight for an adult patient who might bolt from treatment otherwise, but as a standard for everyone it doesn’t make any sense. You know, I really think that many clinicians just don’t get the illogic of body dissatisfaction in EDs. It makes sense that someone who wants to weigh as little as possible would be happier at BMI XX than at BMI XX+1, right? And maybe they would be less likely to relapse at the lower weight? But it just doesn’t work that way. I hated my body ten pounds ago just as much as I hate it now, and I’m much healthier (physically and mentally) for the +10lb difference.

  3. I very much agree, and am glad that my nutritionist does too, mostly. Obviously she would like me to get up into a “healthy” BMI range, but she’s not dead-set on the notion that I have to weigh X amount or else. She prefers to focus more on other indicators of health – how is my blood pressure? How is my energy level? Etc etc. Of course there’s still attention paid to weight, and as I’m still definitely “underweight” by pretty much any rational criteria she would certainly want me to keep looking to gain more, but she’s not going to etch a number in stone and she’s not going to wag her finger at me for not reaching it.

  4. One of the explanations my IP treatment team gave for setting my discharge weight was that it was when the sparkle started to return to my eyes. As though that sparkle proved I was out of danger, able to think straight, and physically well. (I was still in the BMI category that is now classed extreme I think in the new DSM-5) A little bit more nutrition can wake anyone up enough to get some sparkle back – but it doesn’t mean they are better! It’s really hard to figure out what the individual ideal weight should be – but it should be that – individual – and perhaps they should not set one until the person is a lot further along in their treatment. I wonder what tests might be able to determine the ideal point for any one person. I was part of something at the hospital I was at where one doctor who was interested in measuring total body potassium (what was in the muscles rather than bloodstream) had a theory that this reading could better determine when someone was at a good weight for them or not. I don’t think anything came from that, and I remember a friend who was well within normal range having a very low result while I was still very underweight and had a fairly high result at that stage, so I don’t think it turned out to mean anything at all in that context… but it makes me think there has to be some way of actually more accurately pinpointing what will be right for one person.

  5. I’ve long struggled with the concept that some external formula (especially one that is 50 years old and was artificially constructed to apply only to population “health” and not individuals) or that some “clinician” knows better than the body what my ideal body weight is. It’s one of the biggest ED-perpetuating scams there is, discharging people when they reach a BMI of X, Y or Z and allowing us to carve that BMI in stone and stick to it all the way to our premature deaths.

    Even worse, though, is the loss of treatment and therapeutic support when you do weight-restore: I KNOW my brain is working better, but one outcome of that is that I am feeling that dizzying rush of emotions that I have spent the past few decades numbing out through starvation so actually, this is harder than being underweight again.

    The body knows. Don’t tell people what to weigh, let them get to a weight their bodies are happy at. And while and after they are doing that, ramp up the wrap-around support system to help them navigate what has been the hardest part of this journey (at least for me).

    • YES, Spender! Your comment nails it, in my opinion – especially the last two paragraphs.

      • In full agreement with E…Spender’s “nailing” of anorexia’s utility in “numbing out through starvation”..often preferred (by me personally) than having “the sparkle” return to the eye Fiona speaks of and having to grip with flooding realizations …reality in general…and long-ignored feelings.

        I absolutely HATED when my weight…whilst trying to be a good “recovery person” ….over-reached not only my personal “target weight”…but my NATURAL, pre-anorexia weight by ten kilos!!…I had a doctor accuse me of being “hyper-phage” …but I was still restricting!…The thing is…the doctors NEVER warned me/told me about “overshooting” target weight…and when it came on like a tsunami…..I panicked and relapsed.

        I actually had family members remark on “how much better” I looked…”less bouffy”…ONCE I had decided to go back to my prior restrictive ways. This only “confirmed” to me that they saw me as having gained “too much weight back” in recovery…and that they found me more attractive in sick mode.

        Nobody ever told me/prepared me for of the sheer hell of recovery

        • Oh yes, nobody ever prepared me for the hell that is refeeding/recovery either 🙁

          I have constantly battled with having this iron-grip on the weight and eating, that no matter how hard I try, I can’t seem to prise free. I can’t seem to just let it go and give it away. Let my body do what it wants. So we struggle. It gains a bit, and my grip tightens. I loosen the grip and it takes it and sprints away from me and I grab things back again. I just can’t LET IT GO and I wish I could, because it’s exhausting.

          Every time I have been in the refeeding process I’ve always gained weight so much faster than ‘they’ have said I will, and that has terrified me. Terrified me that it will keep going, and that it I must be doing something terribly wrong for it to happen so much faster than it ‘should’ have. I wonder if they had not ever told me that I ‘would’ gain a certain amount of weight per week on their regimen, I wouldn’t have put so much importance on the amount.

          I didn’t ever focus on the actual weight until I was in treatment for my ED. And then it became an indicator as to whether I was a ‘good’ person or not, I could be doing everything I could to fight my Ed, but if my weight wasn’t a good number, I was mud.

          Also hard was the fact that there was SO MUCH that was wrong, so much that I needed help with, but the people all around me focussed only on the number on the scales.

          • Feeling the kindred soul with Fiona…

            My endocrinologist “promised” me he would not divulge “the number” as he instructed me to hop on the scale (I faced backwards)…but proceeded to TELL me just after…He told me he thought it was “better” to know…

            Also…when I did my annual gynecological exam….the nurse looked at my chart…looked at me and said “….Is it really POSSIBLE” that you gained THAT much weight in such a short time?” and “Wow..you must have been REALLY making up for lost time!”

            Needless to say,
            I was DEVASTATED…especially since my gynecologist was “aware” that I was in recovery and had only been out of hospital for seven months….I, alas, relapsed as I saw no discernible “end” to the
            weight-gain “normalizing” period…I feel and identify totally with Fiona’s “pain”…So many OTHER issues need to be addressed

          • Donna, I’ve had similar experiences with my doctor. My PCP advised me to restrict my food and exercise more (KNOWING MY HISTORY!!) to help lower hereditary high cholesterol. Um, seriously? She’s also made comments about my weight gain and such, like “Oh, at that weight you’re obviously over the anorexia.” o.0

            I was devastated.

  6. Yes yes yes yes yessss!! Thank you, Carrie. This is where I struggle with everything associated with the BMI. Please tell me is there one positive to telling people what they ‘should’ weigh? No. Nothing.

    I assume you’ve seen the “Fat Letters.”

    This is even worse among kids. Kids grow taller at different rates. So who’s to say they should weigh this or that? This only promotes insecurities associated with body image. Beyond frustrating.

    • Don’t start me on this. Such a bad idea on so many levels, not to mention the fact that there is NO (zip zilch zero nada) evidence that they actually work.

      If shame helped people lose weight, there wouldn’t be a need for a multi-billion dollar weight loss industry.

      • “If shame helped people lose weight, there wouldn’t be a need for a multi-billion dollar weight loss industry.”

        Best I’ve ever heard it put.

  7. Rock and Roll post, Carrie. Mind melding across the ocean….

  8. I am the mom of a child with selective eating and swallowing phobia,while I understand this condition is in no way AN my child does sometimes sruggle with “fat”talk,well I sould say “did”struggle with it when she was at a lower weight.She lost alot,quickly,and had some of the same symptoms as AN in that starvation mode.She is back where she sould be,her body has settled where it should be and I know that by her state of mind.IMO I believe the body,each body has a predetermined weight that is right for it.But how do we know what that is? Especially with a growing child.

    • Your best bet is to use your girl’s growth charts and make sure she is keeping on track with her general weight percentiles. I don’t advise using BMI percentiles in growing children due to the likelihood of height stunting, so BMI percentiles often need to go higher temporarily so the child can get back on their historic weight curve and then (mostly) height does catch up.

  9. This is the problem with long-standing, chronic eating disorders. I’ve spent most of the past decade and more around the same weight, bar relapses… And I am not counting the past 2 years because that’s been difficult, but still… My weight for that decade has been what I weighed when I started high school. When I had breasts, and a waist, and hips. I look less feminine now than I did as a pubescent teenager.
    Thanks for the reality check Carrie. I’ve been really struggling with recovery this past few weeks, and it’s good to remember that what I think of as normal is probably anything but natural for my body.

    • Same problem here. Adjusting to what my weight needs to be for optimum physical and mental health sucks, because I was utterly fixated on that number for two decades. I try to remind myself that I am where I am, and I certainly wouldn’t want to be 12 anymore, so I can’t expect to weigh that, either.

  10. That is perfect: being 12 sucked! So why would I want to chase that again??
    Realising I’ve dropped bra sizes, when I LOVE buying lingerie is a much better reality check than what I weigh tbh.


      I bought grown-up lingerie for the first time in my life this spring, and it was awesome to have something marginally stylish. It took about 18 months at a healthy weight for the boobs to come in (it wasn’t a drastic change, but the old stuff didn’t fit), but they did. So yeah, there are definitely some upsides.

      • This is so funny, my worst thing about recovery was getting them back. I always regretted that I couldn’t reach a healthy weight and keep a small cup size.

        • I never said anything about a big cup size! Just being able to buy “real” bras. I can’t say I’m always thrilled with my chest, but I have a much wider range of options in that department now that I’m no longer a AA cup!

          • Yeah, I’ve really struggled with the whole fact of my body changing. But I’m trying to remind myself that it’s changing BACK to what it would be before I relapsed this time around… Then I remembered I used to spend a (student) fortune on underwear ten years ago. Trying to remember what I’m like without this is very, very strange sometimes

  11. This is absolutely brilliant. Thank you for writing this. I’m in the UK and we don’t use IBW charts as such but there is the same problem of not reeeally knowing where someone’s weight should be on the BMI scale. I’ve been told that because my periods returned at a low (anorexic) weight I ‘must naturally’ be on the low end of a healthy weight naturally. That’s rubbish and I’m glad I recognise it as such. I don’t know, maybe health professionals like to have something concrete to hang on to.

    • I had the same issue- so do lots of people, because they changed the DSM criteria for anorexia. Menstruation is a necessary but not sufficient sign of return to a healthy weight.

      I’m glad you recognized the nonsense, although sorry you had to hear it.

    • Same! My period returned a couple of BMI points below the AN cut-off and um I think I can safely say that I’m NOT naturally that weight (I’m guessing only a tiny percentage of people are), but because a ridiculous number of health professionals told me that I’d know I was weight-restored once my periods returned, it took me a long time to justify allowing myself to gain to a healthy weight. I think you’re right about them wanting something concrete to hang onto. I’m sorry the same thing happened to you, but I’m glad we are both able to see that the ‘professionals’ don’t always know best…

  12. Sing it with me, and with feeling:

    “It’s called a population Bell Curve, and not a population Stove Pipe Hat, for a REASON!!!”

  13. Another thought: how does using IBW obstruct treament for children…? I mean, you “should” use growth charts, but that’s not always easy, and how do you know what the correct recovered weight is for someone who did not lose weight but stopped growing?

    • I think, ideally you want a combination of centile tracking combined with a height estimate based on parental heights. So you should be able to work out where a baby was on a growth chart in infancy, and what their predicted final height should be, and see where they are in the middle of growing?
      Plus, height velocity and corresponding centiles for height and weight.
      That’s how I’d approach for a child who was malnourished for other reasons.

  14. Hi Carrie,
    Great post! I had a similar experience when I was in treatment. How the hell was I supposed to know what I should weigh and how the hell could a calculator give me the answer? I am pregnant with my second child and I feel like I am in treatment all over again. Someone is telling me how my body is doing it all wrong…despite the fact that all of the other signs of fetal/pregnancy health are all fine. Depending on the source of information, I’ve gained to much or to little. It’s nuts.

    I spent so much time learning to listen to my body and trust it and everyone else has an opinion all over again. Lovely.

    We desperately need a better measure of health…

  15. Wonderful, insightful article! I agree an ideal body weight is range and therefore a bit of a misnomer.

    Jennifer A. Gardner, MD, FAAP, Founder Healthy Kids Company

  16. I lied to my dietician at the IOP program I went to. I believe she asked me at what weight I lost my period and I said somewhere around a BMI of 18.2 . She then estimated me “goal” weight was something like a BMI of 19.2 Which, at my height of 4’10 is about a 5 pound difference. At that weight. So, of course when I went past it, parted of me was freaked out because I went past what she told me I “should” be at, though I knew it was only because I lied to her…soo, yeah.

  17. Well said Carrie, another great blog, thanks for keeping it real!!

  18. I feel I need to add more to my comment as I have been in treatment before and currently going through recovery again. I have been told some crazy things from doctors some who don’t recognize the disease and other who yes tell you what to eat or not eat. A person recovering from anorexia shouldn’t eat??? umm sounds off base to me! A treatment place thought they “cured” me ahh

    Society has a problem and I empathize with you Carrie as yesterday I went to get my flu shot and the women remarked on my size (did not ask her too just guess she felt she needed to ugh!) tiny is good she tells me a nurse umm I wanted to yell no I am anorexic in recovery tiny is not where my body should be please leave your comments to yourself. I didn’t say a thing but quickly changed the subject.

    Keep up your good work speaking up and out, love it!

    • You know, if most people would just STFU about people’s weight/appearance, I think recovery would be SO FREAKING MUCH easier. Sigh.

      • True to that!! In general people should just mind there own because you can’t judge a person by the outside no matter what!!

  19. Great post!

    I’ve found that “Ideal body weights” are often on the lower end of the healthy weight range. For optimal recovery, a BMI of 20-25 should be met. I believe that any sort of pre-calculated target weight is cot conducive to recovery, since even though an individual is restoring weight, they are still CONTROLLING their weight, and manipulating their food intake to keep their weight at a certain number.

    Set point theory, the theory that, when one eats adequately and regularly, their BMI will fall between 20-25 depending on their genetics,build,metabolism,etc… Is more appropriate for ED recovery.

    The focus should not be on weight or food, but on health!

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  21. I’m only beginning to truly work on this. I was kept below the weight I weighed when I was 13 for years. But to keep at that weight I had to carefully control my calories and exercise and it left me hungry and obsessed with food. My BMI was over 20 yet I still felt like I was trapped by my anorexia and I was prone to relapse. I’m working with a new therapist who supports overshooting and set point. I feel like I am finally making progress. It angers me to think I was kept in my ED by professionals.

  22. Brilliant. I remember being dumbfounded in treatment when 0.1 kg determined whether I was allowed out of residential treatment for a few hours, yet at the same time they were telling me not to obsess about numbers. Whaaat?

    • Oh i hear you. I felt the same way because just 0.1 is what used to determine whether I was allowed to go home or stay there, or was admitted or not. Plus, a tiny loss or no gain would get me in huge trouble with no real reinforcement for gains. They TEACH you to obsess about weight there if you haven’t already. It’s not good and rather hypocritical.

      In recent years the ED unit here started not telling people their weight, and the dietician if it was deemed proactive for the person, told them their ‘bmi band’ on request which was a large enough ‘band’ for them not to guess the number or change very quickly. They still focus too much on that though – and we know BMI isn’t accurate.

      Until they start discharging/admitting on state – mental and physical/medical – and behaviours – rather than primarily weight – a lot of people are still going to miss out on treatment that might save their lives.


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