The FastDay Forum

May I just ask our experts about BMI and age and gender discrepancies please. I have read that at age 60 and over women should look to be at 25-27 BMI for good health and averting osteoporosis. Is this true?
Many thanks.

[carorees]

I have had a quick look at the scientific literature and, yes, for women the ideal BMI shifts upwards with age.

This study: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3273446/ shows that:

The BMI associated with minimum mortality for women increased with age. At age 50, the optimal BMI was 22.34 (95% CI, 20.10 to 24.57). The optimal BMI ranged from 19.25 (95% CI, 13.31 to 25.18) at age 18 to 26.86 (95% CI, 25.70 to 28.02) at age 85.

Whereas for men

the BMI associated with minimum mortality was 26.97 (95% Confidence Interval [CI], 26.41 to 27.54)

But of course, BMI still remains a crude tool for assessing visceral fat and its associated risks. The BMI cutoff value for obesity has been shown to be relatively insensitive for identifying excessive body fat: a large number of people with excess body fat actually have BMI values below 30.

The waist:hip or waist:height ratio is a better guide than BMI to your health. For example, this study: http://www.ncbi.nlm.nih.gov/pubmed/23290534 looked at various body measurements and the risk of developing type 2 diabetes in women and found

increased risk for type 2 diabetes was associated with body mass index (BMI) ≥30 kg/m(2) (odds ratio 4.68, 95% CI 2.09-10.49), waist circumference (WC) >88 cm (odds ratio 6.99, 95% CI 1.60-30.42) and waist-height ratio (WHtR) ≥0.5 (odds ratio 3.15, 95% CI 1.91-15.81).

So, if you are a woman of a certain age (over 50) although your BMI target may be a little higher than for a young woman of 18, you need to consider your waist size as being the most important measure and aim for a waist smaller than 88 cm or less than half your height.

Thank you for such a good reply. My current waist is 36.5 inches which seems to convert to 92.7 cms so I've a way to go yet. My half height to waist comes out at 33inches (83.8 cms) so I'm hopefully aiming for that.
Thank goodness you are here to help us all through the maze of conflicting information out there.
:0D

So glad you asked the question AzureBlue as I had been thinking the same. I had found http://www.health.gov.au/internet/healt ... thy-weight
which helped me in working out what I should be aiming for and within the same site came across reference that for older people the acceptable range was 22-26 which seems to tie in with Caroline's informative reply and what you had found.

I don't have the link - will go and look for it but it was from those who have lived life long on the Mediterranean style diet noting lack of osteo and average BMI in women was 23 but as low as 20. Lemme go pull it up.

I do think it's important as others have said to remember that waist size matters most. Also, BMI is difficult because we all have different bone structure. For example I have a BMI slightly less than 23 and my upper arms are quite happy to wave to the neighbours. I also generally look a bit chubby. When I was 25 after my baby, everyone was commenting on how whilst I looked great, the weight seemed to accumulate everywhere, not my belly (thanks, guys!). So based on this, I would hope that I can maintain a BMI no more than 21-22 for my size without concern for osteo arthritis (although I do take HRT at 30, another story). I can't help but think that these recommendations will change as we come to understand osteoarthritis better,
I'm off to look....

Waist circumference for women: a waist circumference of 80cm or over indicates increased risk of obesity related health conditions. A waist circumference of 88cm or more indicates a substantially increased risk.

Waist circumference for men: a waist circumference of 94cm or over indicates increased risk of obesity related health conditions. A waist circumference of 102cm or more indicates a substantially increased risk.

This copied from the linked piece above tells me my waist is 12.7cms over their safe recommendation. Woah! That's a lot to lose at my age!