Poor children in Britain are now fatter than wealthy youngsters demonstrating a total reversal in the weight of the two social classes over the past 70 years.

Traditionally, poverty has been associated with malnutrition and thinnness. But a new study by University College London, which compared children today to those born in the 1940s, 50s and 70s, has found a dramatic switch.

In 1957, deprived 11-year-olds were on average 4.4lbs lighter than those from the upper classes as food shortages and gruelling lifestyles took their toll. But in 2015, the poorest children were 4.6lbs heavier than the richest.

BMI (Body Mass Index) was also found to have risen among the most socially deprived teenagers. For children born in 2001, by the age of 15, there was a 1.4 kg/m2 difference between the classes, the highest ever recorded.

In new research, published in the The Lancet Public Health, the authors said there had been considerable changes to diets and physical activity levels in Britain since the end of the Second World War.