Being born a lighter weight than average affects you for the rest of your life. A study tracking almost 3000 people since birth has found that underweight babies are more likely to shun sport at school and exercise as adults.
Low birth weight has long been linked with obesity and heart disease in later life, but the reasons for this are unclear. Now Ahmed Elhakeem of University College London and his team have found that being born underweight is associated with lower physical activity throughout a person’s life.
“This is important, because regular physical activity in leisure time provides many health benefits,” says Elhakeem. “Our findings suggest that those with low birth weight might need extra support to exercise and realise these benefits.”
Elhakeem’s team made this discovery by tracking the habits of almost 3000 babies born in the UK in March 1946 through to the age of 68. They found that babies that weighed less than 2.5 kilograms tended to do less physical activity, while their heavier peers were 1.9 times as likely to do well in school sports, and 1.9 times as likely to exercise regularly as adults.
Why underweight babies later avoid exercise is unclear. Elhakeem says they investigated a number of factors they thought might explain the associations, including socioeconomic factors, but none of these fully explained the association.
The team suggests the effect may be because lighter babies might go on to have poorer motor skills, lower strength, and worse coordination – factors associated with low birthweight in animal experiments.
Journal reference: Medicine & Science in Sports & Exercise , DOI: 10.1249/MSS.0000000000001077