Women who gain too much weight during pregnancy run the risk of giving their offspring health problems in later life, researchers have found.
Experts discovered that the likelihood of developing cardiovascular and cerebrovascular diseases, or type 2 diabetes during adulthood, was greater in people born to mothers who were overweight during their late pregnancy.
Pregnant women should ensure they lead a healthy lifestyle, with even the period just before birth being "fundamental" to giving their children the best chance, they concluded.
The findings are published as part of a major European obesity project, which concluded that strategies must urgently be developed to prevent obesity in girls and in women of child-bearing age.
The importance of a healthy diet during pregnancy was highlighted by a study which found that the placenta of mothers eating a high-fat diet offered weakened protection to the foetus against the stress hormone cortisol.
This can mean that foetal growth is reduced and these offspring are more likely to suffer mood disorders in adulthood, researchers at the University of Edinburgh found.
Other key findings related to protective caps on the end of DNA known as telomeres.
Having long telomeres protects the DNA to enable it to function and repair, while shorter telomeres are markers of disease and a shorter life-span, scientists said.
They discovered that obesity combined with high weight gain during pregnancy is associated with shorter telomere length in their offspring and as they get older.
But Dr Patricia Iozzo, who led the project, said that even if a pregnant woman was born with shorter telomeres herself and has a high body mass index (BMI) she can reverse the situation by being physically active and produce healthier children.
The link between developing cardiovascular and cerebrovascular diseases and overweight mothers came from research by the University of Helsinki and Folkhalsan Research Centre in Helsinki, Finland, which followed more than 13,000 subjects from birth in the 1930s and 40s until their present age.
Obesity currently affects one in six adults (17 per cent) in the EU - an increase from one in eight a decade ago, according to figures released by the European Commission late last year.
