Levels of obesity are higher in deprived areas of the north of England where residents are poorly educated and have low self-esteem, according to research published today.

Hull was identified as the worst obesity hotspot in the survey of local authorities in England and Wales, with Kingston upon Thames in Surrey ranked the slimmest area.

Data analysts Experian ranked the councils according to the number of local hospital admissions for type 2 diabetes, a disease linked to poor diet and a lack of exercise - and considered a key indicator of obesity.

Examining information on local residents' spending patterns, work history, housing, incomes and lifestyles, the researchers identified the obesity hotspots as working-class areas where residents have a poor education.

The majority of the 10 worst areas were in the North of England and Wales. Hull was followed in the league by Knowsley in Merseyside, Blackburn in Lancashire, South Tyneside and Easington, Co Durham. Merthyr Tydfil and Blaenau Gwent in south Wales came in at sixth and seventh on the list.

The study's author, Dr Marc Farr said high obesity levels were clearly linked to class.

He said: "There are more working class areas in the north of England where obesity levels are higher. Kingston upon Hull is dominated by municipal dependency areas and 30% of houses are on council-run estates.

"Education levels about food are fairly poor and smoking levels are higher than elsewhere. Parents don't educate their children about having a healthy diet.

"They have old-fashioned diets, the traditional diet in that area is fish and chips. We found 10 fish and chip shops in the centre of Kingston upon Hull, whereas there were none in Kingston upon Thames.

"There is a lot more information about diet available for those in a higher social class."

The average life expectancy for men in Kingston upon Hull is around six years shorter than in Kingston upon Thames, according to the Department of Health.

Earlier this month, Kingston upon Hull council announced that all local primary school children will be given three free school meals per day in a bid to encourage healthy eating. The council leader, Colin Inglis said the aim was to "wean" children off junk food.

The research showed that lower-fat and organic foods were bought by better educated and more affluent people, an Experian spokesman added.

"The research suggests a strong correlation between obesity and class, with higher instances of obesity occurring in welfare-borderline and welfare-dependent social types," he said.

"It would also therefore suggest a link between obesity and self-esteem. People who are actually struggling socially in life do tend to have low self-esteem which in turn is reflected in their diet and trends in obesity."

Two social classes, named by Experian as "low horizons" and "ex-industrial legacy" were found to have well above average cases of type 2 diabetes.

Around 1.4 million people in UK have type 2 diabetes, including the deputy prime minister, John Prescott, MP for Hull East. The number of cases is set to double by 2010.