HOW can we live longer? If you are old enough to remember Billy Bunter then you have lived a reasonably long life.

Sadly real Billy Bunters may not be so lucky. It has been known for several years that childhood obesity is dangerous but a recent study from America has shown it is more dangerous than being born with a high cholesterol.

Nearly 5,000 native Americans born between 1945 and 1984 were followed up.

They lived in the Gila River Indian Community, a small area of Arizona. Most were descended from the Pima or the Tohono O'odham tribes.

Although there were 166 deaths under the age of 55 only 22 were from heart disease or strokes and 10 from diabetes, the diseases normally associated with obesity.

Frighteningly there were 59 premature deaths from alcoholic liver disease and nine from acute alcohol poisoning or drug overdose. This points to a serious problem among native Americans. Is this what the once proud tribes have been reduced to? But the study was designed to look at childhood obesity and does not comment on these worrying statistics.

Between the ages of five and 20 their BMIs were measured, which is a ratio of height and weight. A BMI between 20 and 25 is normal, 25 to 30 in overweight and over 30 is 'obese'.

Almost a third of these children had a BMI in the top five per cent and so were severely obese.

The scientists also measured their cholesterol levels, their blood pressure and glucose tolerance.

The glucose tolerance measures how the body handles the common sugar glucose.

A fasting blood sugar is measured, the patient then drinks a standard amount of glucose and the blood glucose is measured again two hours later.

For normal healthy people the blood glucose will be back to normal after two hours but for people with 'impaired glucose tolerance' it takes longer.

People with impaired glucose tolerance are at risk of developing diabetes.

People whose BMI were in the top 25 per cent in childhood were twice as likely to die before their 55th birthday than those who were in the lowest 25 per cent.

People whose glucose tolerance was poor were 73 per cent more likely to die young but there was no link between early death and childhood cholesterol.

High blood pressure only gave a small increased risk of premature death.

These result tie in with other studies around the world.

A study of Welsh children born between 1922 and 1935 showed that fat children do not live as long although in this study premature deaths were not due to heart disease.

In Stockholm looking at people born between 1921 and 1947 it was found that weight gain between puberty and early adolescence increased the risk of diabetes, heart disease and early death.

All the research is pointing one way. Obesity in childhood is dangerous and can lead to an early death. Although everyone worries about their cholesterol, in childhood this is not a serious problem. Of course later in life, especially for people with heart disease or diabetes, it is vital to keep the cholesterol low.

The message from this study and many other is don't let your kids get fat.

Most parents are too young to remember Billy Bunter but my generation should avoid letting their grandchildren look like Billy Bunter.