Kids in the US might be getting lardy but they are starting out life a lot shorter and thinner, according to new statistics.
A study of 36.8 million infants born between 1990 and 2005 show that birth weights in the US are falling but no one knows why.
Scientists have been left scratching their heads after noting a 52-gram drop in the weight of full-term singletons, from an average of 3.441 to 3.389 kilograms.
Emily Oken’s team of crack quacks at Harvard Medical School have ruled out an increase in caesarean sections or induced labours, which shorten gestation.
US women smoke less and gain more weight during pregnancy, which should make babies heavier.
Oken now starts to wonder if unmeasured factors, such as diet or exercise, could explain why babies are being born lighter.
Light weight babies could be at increased risk of heart disease and diabetes later in life.