One in 12 children aged four and five are classed as obese.

Latest figures show almost 1,000 children in Sussex school reception classes are dangerously overweight.

More than 2,000 11 and 12-year-olds across the county are also obese meaning they have at least 20% extra body weight than the average for their height and build.

Health bosses say this extra weight is putting them at risk of developing serious health problems including arthritis, cancer, heart disease, stroke, diabetes and depression.

And they warn the actual number could be far higher as the statistics are only based on youngsters who have been weighed as part of the National Child Measurement Programme.

The figures were released as the national Change4Life campaign was launched in Crawley to encourage youngsters to stay fit.

Yesterday's event at the K2 leisure centre involved community workers, volunteers and health professionals discussing how to tackle the rising tide of obesity.

The aim is to help families eat more healthily and take more exercise to help them live longer.

In Brighton and Hove, at least 170 reception age children were found to be obese 8.2% of those measured along with 370 Year 6 students, 17% of those surveyed.

In West Sussex, 496 reception age youngsters were obese 7.8% of the total as well as 1,034 (14.5%) Year 6 pupils.

East Sussex had 329 obese reception year students, 7.7% of the total.

The area also had 684 (15%) obese Year 6 students.

David Brindley, Brighton and Hove City Primary Care Trust's health promotion practitioner, said: "In Brighton and Hove we have a range of services and activities to help people achieve a healthy weight.

"Your GP can refer you to an expert who can help you find the most suitable programme for your lifestyle and particular needs."

The city also supports the Mend Programme, also known as Mind, Exercise, Nutrition, Do it.

This is for children aged seven to 13 and their parents who attend sessions together twice a week for two hours to find out how to stay fit and healthy.

The aim is to boost children's confidence and self-esteem as well as get them more active.