NHS remove the ‘sex’ discriminator from their bmi calculator

[Dragonasaurus]

Resulting in poorer information being provided to everyone who uses it. Is this really because of the feelings of 0.02% of the population, or is there another explanation?

Maybe someone who supports the trans argument can explain why it is better to provide poorer health information for everyone? Obesity is far more of an issue for the health service than the mental health of a tiny minority. Wouldn’t a warning have been enough?

Yes it’s weird - they require sex for BMI calculation for children under 18 so what happens to the sex difference after that? It obviously doesn’t disappear.

I have been losing weight for about 18 months, I’ve been periodically using the NHS BMI calculator and it has not asked for my sex at all during that time frame. I don’t think this is any kind of a recent change.

A woman and a man with the same BMI will have different muscle and fat ratios, which is to be expected given that women carry more fat than men. It doesn’t destroy the usefulness of BMI as an indicator of health.

I didn’t say there isn’t a difference in body composition between sexes, just that this is not part of the BMI formula or thresholds

I agree, it’s basically saying that mentioning the existence of biological sex isn’t “inclusive” enough.

BMI doesn’t and never has taken body composition into account, so the fact that women carry more fat than men is irrelevant in the calculation. I have a fair bit more muscle than many women my age, and low body fat. The BMI calculators don’t ask for this information so my BMI is at the upper end of the healthy range (approaching ‘overweight’), despite my body fat being about 18-20%

It’s why BMI is of little interest and relevance to some people, including me.

It’s not a flaw though, because the healthy range is just that - a range. So a BMI range of 20-25 takes account of different body types.

But you are still in the HEALTHY range so why complain about this?

This was my understanding. BMI is based on male physiology. As with many things, women are dismissed as 'small males'.

I don’t know why you think I’m complaining @HappyNewTaxYear

I'm about the same height as your husband, and in the bottom end of the healthy range. I assure you I am not emaciated! I prefer svelte! 😀But I am keeping an eye on my weight, cos cannot let it fall further, but it seems stable enough.

https://www.abc.net.au/news/2022-01-02/the-problem-with-the-body-mass-index-bmi/100728416

We are all measured against the average Belgian man of the 1800s.

Its just another instancr of genderpish intersecting neatly with old fashioned sexism, for obvious reasons.

It is an imperfect measure though. I’m not saying it’s not useful, just that one of the limitations is that it doesn’t account for body composition. E.g. there are people with too high body fat classified as normal due to low muscle mass and people who may be classified as overweight with relatively low body fat due to high muscle mass. The first is more common.

If they used to follow up with sex-specific recommendations and they have scrapped that, then no longer asking for sex has a negative impact on everyone.

It is not trans-exclusive to ask about sex, just like it is not disability-exclusive to ask if you have a disability, even though some people with disabilities find the question triggering. They are still being asked, just like people are asked about their relationship status, ethnicity, age and so on. Some people find those questions triggering, Why is this different?

Wtf that is insane!

Women and women hold weight differently so BMI can be very different for all of us. And you just know that they've reverted to the 'original' BMI calculation which only included men, meaning that the calculator is now no longer useful for women.

Is this not just blatant misogyny?!

It’s true to say that the BMI calculations never included a variable for sex. However there used to be different ranges for healthy/obese/underweight for males & female iirc.

in that regard it seems that ethnicity is now acknowledged where sex has been removed - which is baffling:

“Ethnic background
The calculator will also ask for information on your ethnic background.
This is because people from an Asian, Black African, African-Caribbean or Middle Eastern ethnic background have a higher chance of developing health problems at a lower BMI.
When you enter information on your ethnic background, the calculator will give you more accurate advice about your BMI result”

It gives a healthy weight range for an adult of his height. The actual healthy weight for him will always be impacted by other variables.
BMI has always been a blunt tool.

The calculation isn’t affected by sex, so it doesn’t need to be there.

So if sex is irrelevant why do they ask about your ethnicity. Surely the differences there are much less than between the sexes.

Because they have actually adjusted BMI for race - whether or not they should have prioritised adjustments for sex is probably a different question.

The adjustments to BMI for race aren't in the calculation (which is simply the maths of weight in kilos, divided by the square of height in metres) but instead works on (an again generalised) basis that people from particular ethnicities are more likely to store fat round their vital organs etc and therefore that being overweight starts posing health risks at a lower level than for other ethnicities, so instead of "obese" starting at BMI 30, it can be at a lower threshold.

No there isn't - just looked 4th Jan '26 at 14.30 and there's nowhere to comment. Perhaps it's been removed. Anyone have any idea where we can write to complain about this?

https://www.nhs.uk/give-feedback-about-the-nhs-website/

I am confused. It is absolute true that sex is not relevant to the BMI calculation, but are they saying that it is not relevant when determining the healthy ranges?

And if they are different ranges (or would likely be) wouldn't it be beneficial for both sexes for someone to determine more accurate ranges for each?

Agree though that if no-one has done this, then no point including sex, save that as PP points out, both sexes are missing out if further sex specific information that used to be given is no longer offered.

I don’t understand how it can be the same for both sexes. Men have greater muscle mass so surely that needs to be taken into account when developing weight boundaries.

I'm not a doctor but from what I've read BMI really isn't a great indicator of health BECAUSE it doesn't take into account average fat vs. muscle differences in males vs. females, different body types in ethnicities, etc. While BMI can give you a very general overview of where you fall in a healthy weight range - if your overweight, healthy weight, or underweight - it's not very precise. So it seems to me removing the sex indicator is actually moving in the opposite direction of providing the public with helpful, personalized information about their health. A better indicator would be body fat composition, which WOULD be different for males vs. females.

LSS, it doesn't make much of a difference to include or exclude sex from BMI, but BMI shouldn't be used on its own as a definitive indicator of one person's health - male or female. BMI is just one thing that should be considered alongside many other indicators that would be different between male vs. female. Additionally, NHS's response that their decision to remove sex was even partly influenced to by gender ideology proves they are still less interested in providing unbiased scientific resources in favor of a biased ideology.

My BMI on NHS and other calculators that do ask sex is the same. I don't really set firm store by BMI anyway, it should only ever be a guide at best.

However it does ask sex for children. What changes?

Edit: just to add, it still speaks in terms of centiles for children also. Because boys and girls have different centiles. I guess it's just one of those reasons BMI isn't an effective tool.

Yes - as far as I can see, the ranges for BMI are the same for men and women. So no point including sex.

But…due to body composition differences, BMI information needs to be used as a general guide only.