Babies given formula instead of being fed nothing but breast milk for the first six months of life are 25 per cent more likely to become obese.
The World Health Organisation made the claim after surveying parents of 30,000 children, aged six to nine.
The results, unveiled at the European Congress on Obesity in Glasgow, show for the first time how breast milk keeps kids at a healthy weight.
Author Dr Joao Breda, of the WHO, said: “We need to see more measures to encourage breast-feeding, like properly paid maternity leave.
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“We need less inappropriate marketing of formula milk, which may lead mothers to believe it is as good for babies as breast milk.” Children who were never breast fed were 22 per cent more likely to be obese than those fed both breast milk and formula for at least six months.
Sue Ashmore, of Unicef UK, said: “Human milk is specifically designed for human babies.
"Not only does it act as baby’s first vaccine, protecting against infections but it also affects long-term health, including acting as the first defence against the epidemic of obesity.”
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Previous research shows 73 per cent of UK babies start off breast fed but only 45 per cent are getting any breast milk at all at six weeks old.
Just one per cent of UK babies are fed only breast milk for six months, compared to a European average of about 20 per cent.
