A genetic link between low birth weight and the development of adulthood diabetes has been found, according to an international study.
The researchers claim it helps explain why small babies go on to have higher rates of type 2 diabetes as adults.
They said the findings would help target efforts to prevent the disease.
The team, which included scientists from Exeter's Peninsula Medical School, analysed 38,000 Europeans involved in 19 pregnancy and birth studies
The fact that lower weight babies are more at risk of developing type 2 diabetes as adults was already known.
But much of the existing research has focussed on environmental factors, such as the effect the mother's prenatal diet can have on the growth of her baby, rather than genetic ones.
Dr Rachel Freathy, from the Peninsula Medical School in Exeter, said: "It is now important for us to establish how much of the association is due to our genes and how much is due to the environment because this will inform how we target efforts to prevent the disease."
It was recently found that babies who inherit a certain genetic variant in a gene called ADCY5 are at a 25% higher risk of future diabetes than babies who do not inherit it.
This latest study shows that the babies who inherit the genetic variant also weigh less at birth.
Mark McCarthy, from the University of Oxford, said: "It was a surprise to see such strong genetic effects for a characteristic, such as birth weight... these discoveries provide important clues to the mechanisms responsible for the control of growth in early life and may lead us to a better understanding of how to manage growth problems during pregnancy."