Women's waists it seems are some 2 inches bigger and men's waists have expanded another 1.4 inches, providing more evidence that people are becoming fatter.

The growing obesity problem is of concern as experts believe it puts an entire generation in danger of an old age fraught with diseases such as diabetes, cancer and heart problems.

Other studies have shown that Brits are the fattest race in Europe and experts say the statistics provide more evidence of a looming public health crisis.

The obesity epidemic is being blamed on too much fast food, sedentary lifestyles and too little exercise.

Scientists from the charity Cancer Research UK used Department of Health figures to examine how weight and waistlines have changed in recent years.

They compared the measurements of more than 20,000 men and women in 1992 and 1993 with data gathered from almost 12,000 people of similar ages ten years later and found that the average waistline had grown considerably.

Dr. Lesley Walker, of Cancer Research UK, says it is known that a high body weight increases the risk of a number of cancers and it is important this message reaches as many people as possible.

Dr. Walker says a healthy diet rich in fibre, fruit and vegetables, as well as regular exercise can help people lose weight and reduce their risk of cancer.

Soaring obesity rates mean 22.4 per cent of women and 22.7 per cent of men are now classed as so overweight their health is at serious risk.

However it appears that not everyone is gaining weight at the same rate as the analysis indicates that while the fat are getting fatter the thin are staying just as slim.

People under 45 were particularly noticeable as the proportion of men in that age group with a body mass index (BMI) over 35, and of women with a BMI of over 40, doubled during the decade.

BMI uses weight and height to work out whether someone is of healthy weight and a BMI of 30 and above represents obesity.

Lead researcher Professor Jane Wardle suggests young people possibly lead a less healthy lifestyle than their elders and that environmental changes are having a greater impact on young adults.

Professor Wardle says snacking, takeaway meals high in fat along with sedentary lifestyles where many people spend both work and leisure time sitting in front of a computer, are all contributing factors but says genetics too have a role in the growing obesity rates.

The study is published in the International Journal of Obesity.