Being Slightly Overweight Increases Risk of Death when Compared to a Normal Weight

The USA has the highest obesity/overweight adult and childhood rates in the developed world. Approximately two-thirds of US citizens are overweight.

25/08/06 If you are in your fifties and are slightly overweight, your chances of dying during the next ten years are 20% to 40% higher than if you were not overweight at all, according to two new studies, one carried out in South Korea and the other in the USA.

The National Cancer Institute, USA, which led one of the studies, reported on a fifty-year old's probability of dying if he/she were either overweight or obese. It carried out a ten-year study on 527,265 Americans. All those studied were aged 50 to 71 years. Adjustments were made for age, race or ethnic group, level of education, smoking status, physical activity, and alcohol intake.

The researchers concluded that a 50-year-old who is slightly overweight runs a 20-40% higher risk of dying during the next decade, when compared to someone of normal weight. 50-year-old obese people are two to three times more likely to die. These calculations were made on people who never smoked.

Michael Leitzmann, National Cancer Institute, said that these finding are very important, because a substantial proportion of the US adult population is overweight. If overweight is linked to premature death, that's very important to public health, he added.

Leitsmann said "What we need to do is try to encourage people to maintain a healthy weight and avoid weight gain,"

The Korean study looked at 1,213,829 Korean adults, aged 30 to 95 years. The findings were very similar to the American one. It also found that underweight people have a higher risk of death than people of normal weight.

The USA has the highest obesity/overweight adult and childhood rates in the developed world. Approximately two-thirds of US citizens are overweight - this includes one third who are obese.

What is Overweight and what is Obese?

A person's BMI (Body Mass Index) is used by many health professionals to determine whether you are overweight or obese.

-- Underweight = BMI <18.5
-- Normal weight = BMI 18.5 - 24.9
-- Overweight = BMI 25 - 29.9
-- Obesity = BMI of 30 or greater

How is BMI Calculated?

There are two ways to calculate a person's BMI:

1. Metric system - Kilograms and Metres
[Person's weight] divided by [Person's height squared]

2. Imperial System - Pounds and Inches
[Person's weight] divided by [Person's height squared] times 703

The trouble with calculating BMI is that it can class a sedentary 6 foot 2 inches tall man, weighing in at 230 pounds as having the same BMI as a super-fit heavyweight boxer who is also 6 foot 2 inches tall and weighs 230 pounds. The boxer can use a skipping rope for 30 minutes easily, while the sedentary man would be lucky to manage thirty seconds. There is no way these two people have the same health risks.

Some scientists say that perhaps a better way of measuring obesity/overweight, especially for older people, is to calculate the person's waist-to-hip ratio as well as his/her BMI.