The authors, including a team from Edinburgh University, say children born to overweight mothers are at greater risk of health problems in later life.
They say every pregnant woman should have access to dieticians and psychologists to help protect the health of their future children.
During the three-year project several pieces of research were consulted.
In one of the most extensive studies to question whether the health of mothers-to-be can have long-term consequences on their offspring, scientists pulled together several pieces of research across Europe.
One key study, involving 13,000 individuals, revealed that babies born to overweight mothers are more likely to suffer heart disease or strokes or develop type 2 diabetes in later life.
Another analysis from Edinburgh University found that obese women eat a diet richer in saturated fats and poorer in vitamins and minerals during their pregnancy compared to slim women.
In early work, including animal studies, scientists found the placenta of females who ate a high fat diet offered less protection to the foetus from the stress hormone, cortisol.
Offspring were more likely to be small and to suffer mood disorders in later life.
Overall project leader Dr Patricia Iozzo, from the National Research Council, Pisa, Italy, said: "Attention needs to be devoted to the prevention of obesity and becoming overweight among young girls, representing tomorrow's mothers."
Dr Iozzo says the period at the end of pregnancy is particularly important. Her work suggests babies' metabolic health - including the fats and sugars in their blood - may be worse if mothers put on unhealthy amounts of weight at this time.
"I feel the message is a positive one. Mothers can do a lot during pregnancy to look after the future health of their children.
"They must under no circumstances stop eating though. They should ensure they have a balanced diet and make sure they are physically active.
"And I think every mother should have access to a team of health workers during pregnancy - including not just midwives and obstetricians but psychologists and dietitians too."
Louise Silverton, director for midwifery at the Royal College of Midwives, said:"Women should try to be an ideal weight before they become pregnant and, if not, should follow midwifery advice to manage their weight while eating a good diet rich in micronutrients.
"After birth, women need support to develop healthy patterns of eating and exercise.
"For women who are overweight or obese they need support to access weight-loss services to ensure that they are an ideal weight before they embark on their next pregnancy.
The ongoing Dorian project is funded by the European Commission.
A major European obesity investigation has called for urgent action to prevent obesity in women of child-bearing age.