Sunday, September 16, 2007

Strange advice by a war on obesity site

weight concern
Hard to believe but you may be told that your weight is okay, you gain two pounds, and then you are told you should lose sixteen pounds! Or even better: You may be told to be "not overweight" at age 13 but "overweight" at age 12 with the same height and weight.

Surprised? Then you should try out the Body Mass Index calculator at Weight Concern, a leading war on obesity site in the UK. I have tested this calculator with my own height (182 centimetres) and various weights (in kilograms, which is roughly the half value in pounds). For instance, I got this result:

82 kilograms
"Your weight is in the healthy range for someone of your height."
Then, after having some good meals virtually, I gained a little weight, once again tested myself and got this advice:
83 kilograms
"Your BMI puts you in the overweight category. You would improve your health and feel better if you lost 8 kgs. Even a loss of 4 kgs would improve your health."
I have gained one kilogram and should now lose eight kilograms or sixteen pounds? This is really hard to grasp. After having checked the content of the site I have been confirmed that a weight of 82 kilograms is healthy for my height. The way I learned it at school, this makes one kilogram down from 83.

Another thing that leaves me suspicious: They don't ask me, as an adult, about my age and my sex. Is one weight good for all? Hard to believe, and when it comes to old age, a number of studies tell us that a higher body weight is linked to a longer life. And your health status? A higher body weight may be indicating a longer life of heart patients.

What happens between age twelve and thirteen?

For kids and youngsters they have a separate BMI calculator. Well, I cannot shrink myself but I entered my real height and weight values and stepped down my age. Of course, a twelve year old will not be as tall as me, but this should not matter because body mass index accounts for height and just gives a proportion. In other words, as long as the BMI stays within a reasonable bandwidth, the advice should not be affected by my unusual height and weight. After having rejuvenated myself by 46 years I got this advice (emphasis is mine):
"A 13 year old child/young person whose weight is 72 kg and height is 182 cm is not overweight. If you have any concerns that they may be underweight, you should see your doctor."
Not overweight? Underweight? Is there nothing in between? I rejuvenate myself by another year and get this advice:
"A 12 year old child/young person whose weight is 72 kg and height is 182 cm is overweight. It is important that he or she does not become more overweight or obese - you may wish to visit the children and families page, for further information."
I didn't change my weight and my height, but at age 13 I am not overweight, possibly even underweight, and at age 12 I am overweight? If this is not nonsense, what is it?

And what about body fat and hormones?

In every war, propaganda tries to tell evil stories about the enemy. In the war on obesity, body fat is the enemy. Here is what they tell about it:
"Excess body fat is not harmless tissue that you carry around with you as extra padding. Excess body fat produces hormones that can make you susceptible to a number of serious illnesses - the more you are overweight, the greater the risk."
Now let's turn to the facts. Adiponectin, one of the hormones produced by body fat, reduces the risk of diabetes and heart disease and is produced to a lesser extent as body fat grows - a double contrary to the claim. The other hormone, leptin, regulates appetite and metabolism which is not bad in itself. The only problem with this hormone is that the body may lose its sensitivity to leptin, and as a reaction the body begins to accumulate fat which in turn produces more leptin. This excess leptin may increase the risk of some diseases but the source of the problem is probably not body fat but the blunted reaction of the body to leptin. The claim that body fat in itself is a cause of diseases (rather than a concomitant feature) has not been proven in scientific studies.


The Weight Concern website advises people, once classified as "overweight" by rigid official standards, to over-react and lose far more weight as has been stated as healthy by the same standards. There is no study showing that such a weight loss will improve health, and the fact that most people losing weight regain it in the long run shows that the claim of "feeling better" with lower weight is not justified. The BMI formula for young people and children seems to be doubtful to put it mildly, causing an intriguing leap of advice between ages 12 and 13. In order to build up body fat as an enemy, the role of hormones is described in a simplified, contorted and biased way. All in all, you may leave this site more confused than before your visit.

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