The United States childhood obesity crisis may be lessening, according to new research released by the government.

Data from the Pediatric Nutrition Surveillance Systemcompiled by the US Centers for Disease Control, looked at the height and weight of 11.6m preschool children from 43 US states and territories who were enrolled in the government’s nutrition assistance programme between 2008 and 2011. The research was then adjusted to account for differences due to race, age and sex.

In 18 states and one of the territories, the proportion of children classified as obese saw a significant decline over the four year period. By comparison, the obesity rate only increased in three states, with the remaining states showing no significant change over the timeframe.

The previous survey, which was run between 2003 and 2008 showed an increase in obesity in 24 states, with a decrease in only nine.

The research also revealed that children from low-income homes – who tend to be more overweight than their counterparts from richer families – have become slightly leaner in recent years.