BMI/Numbers/Weight Triggers - what's healthy? 20 or 18.5?

hellohefalump · 02-07-2007, 11:53 AM

ok, I'm getting a little confused.

A few people have posted saying that a bmi of 18.5 is healthy. But at the clinic I was in (NHS run, eating disorder unit) they said that was underweight and 'healthy' is 20-25 and nobody was allowed off the weight gain diet until their bmi was 20.

For the record their chart said:
healthy - 20-25
underweight - under 20
anorexic - under 17.5
(there was more on the chart but I've left them out because of triggering potential)

So where are you guys getting the 18.5 number? For me, when my bmi is 18.5 my periods have stopped. I know 'healthy' varies from person to person. I am quite muscular and don't have much body fat naturally, so my healthy minimum is around 22 normally. I realise some people are healthy at lower bmi's. But in GENERAL for the majority of people, isn't healthy 20-25?

surprising mystery · 02-07-2007, 12:50 PM

I am not sure, however i have (according to that) never been healthy as my BMI has never gone past 19, currently at 17 and has been a lot lower in the past. I have seen in many places that BMI of 20-25 is healthy and assumed lower is underweight. But I still know of 18.5 being classed as healthy too.

There (i believe) are moves to not base healthy weights on BMI alone in the future and so I would hope, like in your case, that fat percentage will be used as some people with a 'healthy BMI' are actually really sick. You say your periods stopped at 18.5 so for you that must be very very low.

Take care, I would try to think of it as the more into the healthy range the further you are from your periods stopping as 18.5 and no periods is quite alarming (maybe just to me) :S

xxx

-Tough-Cookie- · 02-07-2007, 01:10 PM

my highest weight when i use to eat ALOT ALOT of food including giant choclate bars most days was only ever at 21 so for me a BMI of 18.5 would be a huge imprvment especialy as my lowest was 14.2 and i'm now 14.7 (4 months into recovery...going slow eh?).... its really dependant on the indivdual i think...

plastic rose · 02-07-2007, 04:30 PM

A BMI of 20-25 is considered "normal". But, according to the World Health Organisation, above 18.5 is still healthy, and under that is underweight, with 17.5 and lower being considered an "Anorexic" weight, and under 15 being emaciation. Many doctors use less than 19 or 20 as underweight but its very possible to have a BMI of 18.5 and still be healthy, so that is considered the MINIMUM healthy level, some people should have a higher BMI than that naturally.

When you lose your period doesnt necessarily indicate how healthy or not your weight is. I'm on oral contraceptives now, so I can't tell whether at this weight I would have naturally lost my period, but I got as low as 17 or so without being on the pill and I didnt lose my period, i barely skipped any in fact. I found that when I started to skip periods was dependant on how much weight I had lost recently. It's losing weight fast and suddenly that most typically causes period loss rather than a low weight alone. Many people don't lose thier period even at thier lowest weight because thier weight crept down slowly.

Its also to do with the persons bone structure etc. Body Mass Indexing doesnt take that sort of thing into account, and therefore is not very accurate. Some athletes or weight-lifters for example might be clinically overweight but its all muscle, and they have barely any body fat. Especially if you have not grown fully yet, your BMI can be naturally underweight. It depends on the person.

Hope that answers your question somewhat.

EyelinerAndCigarettes · 02-07-2007, 04:49 PM

I personally think it depends on the persons body structure.

xx <3 helen

bunny punk · 02-07-2007, 06:09 PM

i've been curious about this too. i've seen it before where 19 is healthy, where 18.5 is healthy. i don't know which is correct. I think the guidelines that they gave are good ones. i would just follow what they have. the world should just decide on one chart and guideline to follow to eliminate this confusion because the way things are now just creates confusion. thats just me though.

sammi

hellohefalump · 05-07-2007, 10:40 AM

I was told at the ed clinic that they set target weights at bmi 20 because any lower, if you get genuinely sick (eg: food poisoning or something) through no fault of your own, you're back under 17.5 very quickly (anorexic weight).

hellohefalump · 05-07-2007, 10:48 AM

I know it's different for different people, I was talking in general. For me, when my bmi hits 20 people start saying I look too thin! But I know some people who look alright at 18. I'm a very muscular person, even though I don't exercise that much (if at all...) it's just the way I'm built. I used to know someone whose bmi was about 24 but she looked underweight and didn't have periods. She was a gymnast and had LOADS of muscle.

Don't period's stop when your body fat goes below a certain percentage rather than your bmi?

plastic rose · 05-07-2007, 11:19 AM

^ When your periods stop depends on a LOT of different factors. It depends how FAST you're losing weight. Your body adapts to lower weights, but it takes time, so if you lose weight slowly you might be a lower weight / body fat % when you lose your period than if you lost weight very quickly because your body wouldnt have had time to get used to it and it throws everything off much earlier.

It also depends on where you carry your weight naturally, the amount of fat around your hips, bum and abdomen in particular, because it is the fat around that area that keeps you fertile.