More evidence that the ‘overweight’ are not risking their lives

The body mass index (BMI) has for a long time been the standard measurement used to determine whether someone’s weight is ‘healthy’ or not. BMIs (calculated by dividing weight in kg by the square of someone’s height in metres) of 25 or more are generally regarded as ‘unhealthy’. The suggestion is there are somehow mortal dangers from having a BMI in this range. However, good hard measures of health (like risk of death) show that individuals who are labeled ‘overweight’ according to the BMI enjoy at least as good health, if not better, than those traditionally labeled as ‘healthy’ (e.g. a BMI of 18.5-24.9). For more about the science which shows this see here.

The largest body of evidence regarding the non-hazards of being overweight (cited in the article linked to above) come from the USA. Do they translate to other parts of the World? In a study published recently in the International Journal of Epidemiology the association between BMI and overall risk of death was assessed in a group of almost 76,000 individuals from a rural Indian population (Kerala state, South India). These individuals were monitored over nearly a decade. Here are the results for men, using a body mass index of 18.5-22.9 as a reference point:

BMI >16: risk of mortality increase of 26 per cent

BMI 16-18.4: no statistically significant relationship with risk of death

BMI 23.0-24.9: no statistically significant relationship with risk of death

BMI 25-27.4: no statistically significant relationship with risk of death

BMI >27.5: no statistically significant relationship with risk of death

Results for women were similar.

Low body weight is associated with an increased risk of death. But, here again, it seems that being ‘overweight’ does not put individuals at heightened risk of death.

Better measures of health status and risk of death appear to be waist circumference and the waist-to-hip ratio. For more about this, see here.

References:

Sauvaget C, et al. Body mass index, weight change and mortality risk in a prospective study in India. Int. J. Epidemiol. 2008 37: 990-1004

3 Responses to More evidence that the ‘overweight’ are not risking their lives

  1. rob clark 5 November 2008 at 9:57 pm #

    Thanks for this, Dr Briffa.

    As someone who works with elite sportsmen and women, it has long been a standing joke in my field that the likes of Sir Steve Redgrave and Lawrence Dallaglio would be considered obese using the BMI method.

    I suspect that their nutritionists and fitness advisers, not to mention they themselves, would beg to differ…

  2. helen 9 November 2008 at 10:42 pm #

    The more i read about so called “physical” causes of disease such as the consumption of various foods or lack of them the more i am inclined to believe that it isn’t so much what we eat it is how we are ‘feeling’ when we eat them and more importantly how we ‘feel’ about the various foods we eat. for example – if we believe something is bad for us it is or if we are eating because we feel depressed or have you ever noticed that if you are in a really good mood and not thinking about the food you are eating at all that you actually do not put on weight is it only when you start believeing or feeling guilty about what you are eating that it starts effecting you? and also how when you are feeling good you actually make better food choices opting for more natural unprocessed foods and finding you are more satisfied with less of it as well? isn’t it interesting that when you are feeling negative type emotions you actually end up indulging in the negative non-nutritious types of food thinking that this self destructive behaviour will somehow make you feel better? strange is it not that feeling pressured, stressed, sad, unworthy all those lower end emotions, or even that you are lacking or feeling empty somehow makes you eat all the rubbish?? i mean who ever goes to carrots for comfort food and why is it that these foods actually don’t comfort us at all they just increase our feelings of guilt or start us worrying what the effect of all this “bad” food is going to have on us? ever wondered why all this beating the drum of “bad” foods and how terrible the health crisis is is only creating more of the same?
    Maybe the answer is simpler than we are even willing to contemplate, maybe choosing to ‘feel good’, deciding to think a better feeling thought about something or someone no matter where you are in your life in any moment is something worth persuing as a cure to what ails you.

  3. Hilda 12 November 2008 at 1:48 am #

    What evidence is there for this theory, Helen?

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