While eating a balanced diet will undoubtedly help dieters shift some extra baggage, physical activity is a key component to fighting the flab, one expert has said this week.

According to the National Obesity Forum, the lack of sport undertaken by those who are overweight is largely responsible for their ongoing battle with the bulge. The organisation's comments follow figures released earlier this year by the Information Centre, which revealed the problem of obesity in England.

The centre's Statistics on Obesity, Physical Activity and Diet: England report found that in 2006 24 per cent of adults were classified as obese, which was a 15 per cent increase compared with 1993. The statistics showed that men and women were equally likely to be obese, but did indicate that females are more prone to being morbidly so.

However, the study revealed that the uptake of physical activity had increased in both men and women since 1997 by 40 per cent in men and 28 per cent for women. Sadly, waistlines appeared to have expanded at a similar rate. The Information Centre found that 37 per cent of adults' bellies had expanded in circumference in 2006, compared to 23 per cent in 1993.

Dr Colin Waine, chairman of the National Obesity Forum, warned that the battle of the bulge is a serious, even deadly, fight. He noted that those who are overweight should not be encouraged to accept their body shape as it could be potentially harmful to their long-term health.

He explained: "I don't think there are any causes to celebrate [obesity]. It's associated with 45 comorbilities and among these are some of the biggest killers in modern society.

"There is no justification at all in celebrating - there is justification in trying to reduce its prevalence and try to help people who are obese reduce their guide metabolic risks."

Such risks are highlighted by the Information Centre's report, which asserted that women aged over 35 years of age with an increased waist circumference are four times as likely to develop type two diabetes. Men with expanding waistlines are also doubly at risk of developing this condition, compared with those who are maintaining a slimmer stomach.

Dr Waine advises that in order to avoid this fate fat fighters should adopt a healthier eating regime, which involves reducing their fat intake and eating more fruit and veg, and undertaking more exercise. He says physical activity can be incorporated into an individual's lifestyle gradually, in order to make the adjustment sustainable.

The expert blamed changes in the modern environment for people undertaking less sport and putting on weight in the 21st century. He concluded: "The way we lead our daily lives has taken any physical activity out of them, so the end result is expanding people and becoming obese."