The widely-discredited Body Mass Index (BMI) method of measuring how fat a person is took another hammering today. Scientists in the USA have announced a study showing that an "overweight" BMI is not linked to poor health at all, and even an "obese" rating seems to be nothing to worry about for under-40s.

“A lot of people make a big deal about those overweight BMIs," said Brant Jarrett of Ohio State university.

"But we didn’t see a difference [in health] between overweight and normal-weight adults across all age groups. For college-age adults, this should help them realize that they don’t have to worry so much if they have a BMI of 27 or 28. Some young people with these BMIs feel like, ‘I’m going to have all these problems, I need to try 50 different diets.’ And what is all that stress and dieting doing to your body? Probably more damage than the extra 15 pounds is.”

British and American health authorities class someone as "overweight" if their BMI lies between 25 and 30, and "obese" after that. BMI statistics underlie the vast majority of "obesity epidemic" headlines, and are often used by the healthcare industry to justify soaring costs.

But according to Jarrett, "overweight" people don't get ill or require medical treatment any more often than "normal" ones. Even the "obese" show no difference until past the age of 40.

Among the over-forties obese people were significantly more likely to be taking medication for a health problem related to physical factors (as opposed to mental conditions, which were removed from the statistics). Even then the difference between norms and fatties was barely bigger than that between men and women - women are much more likely to be on medication than men are.

In fact, normal-BMI US women over 40 are almost as likely to be on medication as obese-BMI men: the proportions are 57 and 61 per cent respectively. It would seem that simply being female is pretty much as bad for you - and as expensive for society to pay for - as being a fat man.

Unsurprisingly almost 70 per cent of obese-BMI ladies in the study were on relevant medication, 9 per cent more than among the norms. The reasons why women use so much more medication than men are unknown, says Jarett.

The general increase across the whole US population over time in the proportion of people taking medication could be linked to the parallel rise in BMI, the scientist adds. But it might also simply result from "more aggressive physician approaches to treatments that accompany advances in technology".

Or in other words the creeping conversion of the Western citizenry from healthy people to ill ones - and the society-crippling expense of this - might be doctors' and the healthcare industry's fault, and not caused by idleness and pie-scoffing after all.

The study is published in the International Journal of Obesity. ®

The BMI method always struck me as heavily flawed, but I still know I'm fat

Deliberate pun?

The BMI method always struck me as heavily flawed, but I still know I'm fat

My aim for the next 12 months is to become officially overweight, and reduce my body fat percentage

lack of money at the end of the month means it's hard to keep up the right diet to keep losing body fat.

I'm very curious about that statement which I hear quite often from different people.

My general experience is that relatively healthy food such as beans and rice are cheaper than fatty food such as pie and chips.

What do you consider "the right diet"? I'm mostly eating chick pea and carrot salads right now, and that's costing me about £2 a week!

The "right" diet for losing the last bit of body fat is almost exactly the opposite. High protein, quite a lot of food throughout the day (in small meals) low carbs (especially in the evening), etc...

It has taken a long time before I could tolerate salads. My mum basically made salads for months of the year and I was simply sick of them by the time I left home.

10 years before I could stomach it again!

These days I use a very modified recipe that is barely recognisable: