Age-old advice encouraging expectant mothers to eat for two during pregnancy could condemn women to a life of obesity and illness, a new study has found.
Researchers have discovered that too much weight gained during the gestation of a baby more than quadruples the risk of women being overweight decades later.
That in turn could lead to increased risk of diabetes, heart disease and other problems associated with being overweight.
Now they say the advice given to expectant mothers should be radically altered so that their long term health is given as much priority as that of the baby.
“For the last 40 years the whole issue in weight gain in pregnancy has worried about what it would do to the children,” said Professor Philip James, chairman of the International Obesity TaskForce (IOTF) who has developed guidelines for the World Health Organisation.
“People didn‘t worry about what would happen to the mother, they would worry about what would happen to the babies.
“Now we have a huge amount of evidence that weight gain in pregnancy is important. We have to have obstetricians on the alert and seeing how do we control this weight gain.”
In the past doctors and medical staff emphasised the importance of weight gain because they were worried about low birth weight and the development of the unborn child.
Concerns about the mother’s long term health were given a lower priority as it was assumed they would lose the weight after pregnancy.
It was said that putting on around 12 kilograms (one and three quarter stones) was perfectly healthy for the woman and the baby.
But now the new research by Dr Abdulah Al Mamun at the University of Queensland has shown that a “relaxed” approach to the weight of the mother can lead to a lifetime of obesity.
The researchers, who presented their findings at the International Congress On Obesity in Stockholm, tracked the weight and life of 2,026 women who gave birth between 1981 and 1983 in Brisbane, Australia.
They found that a third of them put on more weight than they needed during pregnancy, a quarter gained too little and the remainder got it right.
The women who put on too much weight were more than three stone heavier 21 years later, those who kept their weight under control were just over two stone heavier in the same period since their birth.
The women who had gained too much weight were four times as likely to be obese and more than twice as likely to be overweight. The obese women were 40pc more likely to be diabetic.
The findings suggest it is much harder than previously thought for women to shift the extra pounds after giving birth – and that advise should be changed to stop them putting on the weight in the first place.
Dr Al Mamun said that it was not known whether the pregnancy just highlighted mothers that were sensitive to weight gain or that the weight gain itself changed their ability to return to normal.
Professor James said: “This is extremely research and we now need to focus far more on nutrition in pregnancy.
“We now have to move from the old story of telling mothers to eat whatever they fancy and put on 12 kg in weight”,
“The worries about the health of mothers should be put alongside worries about the health of their babies.”
The new research follows draft guidelines issued by the National Institute for Health and Clinical Excellence (NICE) which are now out for consultation.
They suggest that “eating for two” is a myth and that mothers-to-be do not need to drink full-fat milk or change their diet at all for the first six months of the pregnancy.
Even in the last three months they need just 200 extra calories a day - the equivalent of a small sandwich.
The new advice on weight management during pregnancy comes as the number of obese mothers is rising, with almost one in four women being obese and a further third overweight.
It says women should be advised that being fat puts their baby at risk, but not told to lose weight.
Instead they should be helped to shed excess pounds before getting pregnant and after they have given birth.
The Royal College of Obstetricians and Gynaecologists says the recommended maximum limit for pregnancy weight gain is 10-12 kilograms, around one and three quarter stones.
Telegraph Media Group Limited