greyhoundtom wrote:I have difficulty seeing the correlation between hip and waist size as a genuine guide to a healthy body shape, as most obese people also carry a fair amount of blubber around their hips.
Have you seen a fat person with a narrow waist? I haven't.
But then according to the experts blubber below the waist does not matter, only a fat gut is a problem.
No. Research indicates that abdominal fat increases the risk of disease and this is not correlated to body weight. Although the chances are that a person with high abdominal fat will fit into the "overweight" or "obese" categories, a person with a "normal" body weight can still have dangerously high levels of abdominal fat.
greyhoundtom wrote:As far as iâ€™m concerned just another excuse by an overweight nation to dodge the issue of obesity.
I am concerned too. I am concerned that we have been lied to by the weight loss industry and weight loss drug companies that "normal" BMI is healthy. For an individual, the evidence is not there. This is a public health issue and it is very
serious. There is a reason why the government is running the "Measure Up" campaign targeting waist measurement and not a BMI related campaign... there is little evidence supporting BMI as a measure of health but there is evidence supporting using Waist-to-hip ratio and waist circumference. Waist-to-hip ratio and waist circumference are superior to BMI.
Because I am concerned about my health and want to reduce my risk of developing cardiovascular disease I have been researching this. Here one study I found: http://www.nejm.org/doi/full/10.1056/NEJMc1014730
This is what it says:
In practical terms, the relationship between BMI and all-cause mortality remains uncertain.... Waist-to-hip ratio and waist circumference are superior to BMI in predicting all-cause mortality, the rate of death due to cardiovascular disease,2,3 and the association between obesity and myocardial infarction.4 The waist-to-hip ratio, in particular, shows a low measurement error and high precision, and it is without bias over a wide range of ethnic groups.5 Since the waist-to-hip ratio is clearly a better predictor of total mortality than BMI, it is likely to be associated with death from obesity-related cancers. Standardized measures of central obesity should be included in future population studies.
Here is another study: http://ftp.utalca.cl/profesores/gicaza/Respaldo%20FONIS%20RCV/Marrugat/InterHeart%20Lancet%202004.pdf
This is what it says:
Body-mass index was related to risk of myocardial infarction, but this relation was weaker than that of abdominal obesity (waist/hip ratio), with body-mass index becoming non-significant with the inclusion of waist/hip ratio in the multivariate model (data not shown). Before multivariate adjustment, abdominal obesity (top vs lowest tertile) doubled the risk of acute myocardial infarction, but the effects were substantially diminished after adjustment for other risk factors, especially apolipoproteins.
Here is what the World Health Organisation says: http://www.who.int/mediacentre/factsheets/fs311/en/
BMI provides the most useful population-level measure of overweight and obesity as it is the same for both sexes and for all ages of adults. However, it should be considered a rough guide because it may not correspond to the same degree of fatness in different individuals.
So BMI is
a good measure for populations but NOT
a good measure for individuals.
Another study: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2894715/
Although BMI is the most common method to define overweightness and obesity in both epidemiological studies and major clinical trials, clearly this method does not necessarily reflect true body fatness.
It is clear that excess fat, particularly abdominal fat, increases risk of disease. It is also equally clear that BMI is not useful for measuring body fat in individuals. Fat and abdominal fat can be measured with a tape measure but not with scales because scales treat fat and muscle the same. We need a way to measure our risk factors that actually works and is supported by research. There is no point reaching a "normal" BMI if real risk factors are not reduced.