The research – believed to be the first of its kind – tracked increases in body mass index (BMI) for more than 56,000 people born in the UK from 1946 to 2001.  

The work was carried out by researchers at University College London and Cambridge University who found that children born since 1990 are up to three times more likely than earlier generations to be overweight or obese by the age of 10.

Since 1946, every generation has been heavier than the previous one – and the most overweight people are becoming even heavier. For example, by the age of 11 the heaviest two per cent of people born in 1946 had a BMI of around 20, compared to a BMI of 27 for the most obese children born in 2000.

People are also becoming overweight or obese younger. Half the men born in 1946 were overweight by the age of 41, whereas men born in 1970 were overweight 11 years earlier (age 30). Half the women born in 1946 were overweight by the age of 48, whereas women born in 1970 were overweight seven years earlier (age 41).

The researchers also found that five-year-olds from the poorest households are twice as likely to be obese compared to children from better-off homes. By age 11, they were almost three times as likely to be dangerously overweight.

But the government has been criticised for what have been called ‘weak’ efforts to act on the evidence. One of the most controversial initiatives is a voluntary target for manufacturers to cut sugar in children’s food and drink by 20 per cent over the next four years. Reductions in sugar content will be monitored by Public Health England.

Funding for school sports and breakfast clubs will be boosted from revenues of the Soft Drinks Industry Levy – or so-called ‘sugar tax’ – that will come into force in 2018.