Babies should not be bottle-fed after their first birthday, according to researchers who found that toddlers who drink a lot of milk are more likely to become seriously overweight.
A study of almost 7,000 children found that those who were still being put to bed with a bottle of milk at age two were 30pc more likely to be obese by the time they turned five.
Academics believe that infants who are used to drinking a lot of high-calorie milk go on to eat a lot of fattening food.
They say that doctors and parents should aim to stop babies being dependent on bottles of milk by their first birthday.
Rachel Gooze, from the Centre for Obesity Research and Education at Temple University in Philadelphia, said: “A 24 month-old girl of average weight and height who is put to bed with an 80z bottle [just less than half a pint] of whole milk would receive approximately 12pc of her daily calorific needs from that bottle.”
It has long been known that newborns fed on formula – usually made from cow’s milk with added vegetable oils and vitamins – gain weight faster than those who are breastfed.
Some parents continue to give babies bottles of cow’s milk or special toddler formula during the day or at bedtime even after they have moved on to solid food, from six months onwards.
In a paper published in the Journal of Paediatrics, researchers analysed existing data on 6,750 American children born in 2001 to study the correlation between prolonged bottle use and obesity.
They found that as many as 22pc of children either used a bottle of milk “as their primary drink container” or “were put to bed with a calorie-containing bottle”.
Of this group, 23pc were obese by the time they were 5.5 years old.
Dr Robert Whitaker from Temple University said: “Children who were still using a bottle at 24 months were approximately 30pc more likely to be obese at 5.5 years, even after accounting for other factors such as mother’s weight, the child’s birth weight and feeding practices during infancy.”
The authors believe that “drinking from a bottle beyond infancy may contribute to obesity by encouraging the child to consume too many calories”.
They state that children should be weaned off milk from the age of one, with the help of doctors.