A third of final year primary school children are overweight or obese, figures suggest.
Last year 33.9% of year six pupils, aged 10 or 11, weighed more than they should - a slight increase from 33.4% the previous year.
The Health and Social Care Information Centre (HSCIC) said year six pupils in urban areas were more likely to be obese than those who live in towns and suburbs.
The percentage of children in reception who were overweight or obese was 22.6% in 2011/12, the same as the previous year, the figures from the National Child Measurement Programme show.
The programme, which checks more than one million children in England, measures the height and weight of children in reception, who are generally aged four and five, and Year 6 pupils.
The highest prevalence of overweight and obese children in reception was recorded in the north east of England. London recorded the highest rates in Year 6 pupils.
Levels of obesity were highest among black children and lowest among those of Chinese descent. Children who live in areas of high deprivation were also more likely to be obese, the report adds.
HSCIC chief executive Tim Straughan said: "The figures show that the proportion of Year 6 children who are either overweight or obese appears to be still increasing slightly. This differs from the picture for reception-year children, for whom prevalence of obesity remains level.
"The National Child Measurement Programme measures more than one million children and is the most robust snapshot of obesity levels among children in England."
Public Health Minister Anna Soubry added that a new campaign to encourage healthy eating is to be launched by the Government in the new year. She said: "Being overweight can do serious damage to our health so we must reduce levels in children to give them the best start in life. That is why we are already taking action to encourage families to eat healthily and get active."