Weight Loss NHS

Is BMI Helpful?

I know it gives you a guide but I really struggle with how accurate it is as a benchmark. I'm overweight but apart from that I am healthy, fit and active, and when Im watching the Olympics on TV I feel a lot more active than I actually am!

But according to my BMI I am significantly obese, if not morbidly so, with a score of 29.2. I recently did a similar exercise at a 'well man clinic' and scored 25 - so not sure why there is variation, but in any event the conclusion is that I need to loose over 4 st to be 'healthy' i.e. again a weight of roughly 11st 5 lbs. I haven't been that weight since I was 15!

Does anyone know how accurate the BMI approach is?

I was going to set a target weight loss of 1st 10lbs, which feels achievable and definitely beneficial, but losing 4 stone would make we look seriously ill!

12 Replies

a BMI of 29 is not obese... 30 is the threshold.

Also BMI should be considered in the interval, even if many suggest you to stay in the middle (I do not think i have ever been in the middle of normal weight)...

I think it is a good starting point to realize there is something to be changed, but some time your body won't allow to get to 25 or less. There is plenty of tools online, have a look here:


after the calculator it gives links to other information.

all the best



Thanks Marco that's reassuring, I don't think I look obese so was concerned.

Thanks for the link to the tools, I'll have a look

1 like

For me the BMI gives me a bit more focus. I consider my tape measure as a more effective tool. If a waist measurement is bigger than the hip measurement then I would think I was in trouble.

BMI doesn't effectively reflect body shape changes. I am burning fat and strengthening muscles and can wear smaller clothes than a month ago without weight loss


Agreed - just bought my tape measure and a real shock when I measured - so decided to use cm as it will hopefully show a reduction faster!


It was actually measures not BMI which put me into the correct state of mind of getting healthier and reduce the fat % in my body. I rarely check the BMI, go for weight and then (is weight stable) measures.


BMI is a 'one size' measure but just one indicator of health, other indicators are a tape measure, (especially waist) body fat percentage and dress size 😊 Having been 'obese' (a word I really dislike btw) I am now 'overweight' but at a recent pre-op assessment the surgeon said anything under 30 was fine!! So, I guess it's about how we feel in our own skin. I am going for the "healthier"BMI rather than "healthy" 😊 And hope to stay there . . .


Thanks just got the tape!

1 like

Personally, I think BMI is quite limited. It is a reasonable guide - but, honestly, if we can grab handfuls of blubber around our middles, don't we know we are too fat, without knowing our BMI?!

I think it is more useful to know what your body fat % is, and BMI won;t tell you that. Men in particular can be very heavy, yet a lot of the weight is muscle. Rugby players are a good example of this. They are fit, but usually show up as obese on a BMI measure. I am the opposite extreme, being a fairly small-built woman. I'm always within the healthy BMI, so don;t get nagged by my GP, but my body fat % is worryingly high.

You could try the scales in Boots once a month which measure your body fat% for 70p. If you lose 1stone 10lbs of fat, you should see a big difference in your body shape and fitness, and then you can decide based on your fat % if you need to lose any more.


Thanks I think thats a really good point as an ex-rugby player I know what you mean when I played I was 16 Stone+ but could run 100 m in 14 seconds.

Is there a way of working out your body fat %? In the meantime I'm off to boots!


Hi, glad to help. I don't think there is a way of working it out yourself without the special scales, as you can't know how much of your weight is fat, muscle and water without them. At the gym, the physio can use calipers to pinch you on your arms, legs and tummy, and can measure it that way. It might be possible to buy a pair of calipers to use at home, I suppose.

I think re the Boots scales, it's good as well to weight at the same time of day if you can, so that you're comparing like with like, just like the scales at home.


Hi loser kip9252

The BMI figure is just that. A figure that doesn't take into account body types shapes or mass. It is just a figure. Body builders and athletes are often on the obese scale on a BMI range because they weigh more than they should purely because they have more muscle.

I would say, ignore this for now and just try and lose weight to a weight where you are happy and feel healthy in yourself. I thought if I ever got down to 14st 7lbs I'd feel fantastic. Well I've lost over 150lbs and am now 14st 5lbs but feel as if I can get down to the 13's and that is now my new target. Its more about how you're feeling rather than what others think or feel.

Good luck with your target of 1st 10lbs. Once there just re-evaluate the situation. If you're happy then fantastic, if not change.

Good luck


Thanks I will ignore BMI, but well done on the 150lbs loss - fantastic !


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