The number of overweight has doubled in the world

A recent study showed that ten of the world a person is obese. Accordingly, in the last thirty years the number of obese people has doubled. This study done by the United States and Britain, and the results are published in the journal Lancet.

Imperial College and Harvard University researchers in London from 1980 to 2008 of the ( BMI ) body mass index, cholesterol and high blood pressure or high blood pressure studied. Researchers say that in many developed countries reduce high blood pressure and cholesterol levels, but obesity is increasing all over the world.

Obesity, high blood pressure and cholesterol can cause heart disease three. Statistics show that 9.8 percent of the world in 2008 and 13.8 percent of men and women were obese had a BMI ( Body Mass Index ) over 30. If you compare data from 1980, 4.8 per cent and 7.9 per cent of the women were obese.

Obesity in Pacific Island countries is highest in the world and the average BMI ( Body Mass Index ) is between 34 to 35.The South - East Asia and sub-Shariy African countries, more than 70 percent. But the rest of the world's income in relation to obesity and high-income countries, obesity has increased.

In most rich countries between 1980 and 2008 in the United States increased BMI ( Body Mass Index ). The women to men in the New Zealand and Australia is the number of obesity cases after the United States and Australia met in the UK. In some countries of Western Europe, people have managed to maintain their BMI ( Body Mass Index ) levels unchanged.

Belgium, Finland, France, Italy and Switzerland in the woman's BMI ( Body Mass Index ) did not increase. While Italy and Switzerland in the men's BMI ( Body Mass Index ) rose only marginally. In rich countries the increase in obesity and high blood pressure in many countries that has succeeded in reducing cholesterol.

In many countries the problem of high blood pressure has decreased. In the case of women in Australia and North America have high blood pressure and cholesterol reduction. While the world has decreased in cases of high blood pressure. European countries, the UK has the lowest reduction in blood pressure cases.

Eastern and Western African countries and the Baltic countries had the highest blood pressure levels. While Australia, North America, Europe and other Western countries have reduced cholesterol levels significantly. The East and South East Asia and Pacific region increased the amount of cholesterol in the blood.

The problem with BMI.

According to my Body Mass Index, I'm just obese. The word "obese" conjures-up images of people with huge fat bellies waddling along. Sure I'm overweight as I love my food, but I don't have a huge fat belly and I don't waddle! The problem with BMI is that it's a simple calculation involving body mass and height.

BMI = body mass (in kg) divided by the square of height (in metres).

I will now demonstrate how two people with identical body compositions, waist measurements and heights can have different body masses (and thus BMIs). Consider the body as a cylinder with the legs as two inverted cones each having half the diameter of the body at the top (it keeps the maths relatively simple). I shall ignore arms & head!

Volume of a cylinder = Pi x Radius squared x Length.
Volume of a cone = 1/3 x Pi x Radius squared x Length.
Mass = Volume x Density.

Length of legs + body = 160cm.
Body diameter = 30cm.
Therefore, body radius = 15cm.
Leg diameter at top = 15cm.
Therefore, leg radius at top = 7.5cm.
Leg & body density = 1g/cubic centimetre.

I have 75cm long legs + 85cm long body.
She has 100cm long legs + 60cm long body.

My legs = 4420g each. My body = 60082g. My total body mass = 68922g = 69kg. If my height = 1.6m, my BMI = 26.9.

Her legs = 5900g each. Her body = 42411g. Her total body mass = 54211g = 54kg. If her height = 1.6m, her BMI = 21.1.

See the difference? 1cm of legs weighs much less than 1cm of body. People with long legs and a short body have a significantly lower BMI than stumpy-legged long-bodied people like me. In addition, people with narrow builds and people with very little muscle have a significantly lower BMI than people with wide builds and people with a lot of muscle.

Thanks to Wolfram Alpha for doing the calculations.

P.S. According to her BMI, this 5 year old girl is overweight.