Professor Colin Boreham from the University of Ulster school of Applied Medical Sciences and Sports Studies also claims that children's diets are healthier than they were some years ago.
"While it's true that our children are becoming fatter, it's also true that they actually eat less fat and fewer calories in their diet than they did even 10 years ago," he said.
The real reason why children are getting heavier is a result of insufficient exercise, argues Professor Boreham, a co-author of 'Five A Week', the recently published report from the UK government's chief medical dfficer on links between physical activity and health.
But despite Boreham's argument, healthy foods targeted at children represent a growing opportunity for the food and drink industry, as media attention to the rising numbers of obese children increases parental concern about the family diet.
Research carried out by the UK-based Engine House consultancy found 47 per cent of UK parents regard their children's diet and exercise as one of the top three things they worry about.
A survey found that many parents are already making moves to improve their children's diet with a staggering 81 per cent limiting the amount of carbonated drinks their children drink, and 14 per cent banning carbonated drinks entirely.
Some 30 per cent of British five-to-nine-year-olds are overweight or obese and this is expected to rise to 36 per cent by 2008, according to figures from Datamonitor. A recent report from the firm also suggests that there is evidence that parents are now placing greater importance on health as opposed to convenience when making purchase decisions.