Consuming a special diet rich in omega-3 fatty acids such as fish oils during pregnancy may not protect the child from becoming overweight or obese, a new study has claimed.
In Europe, almost one in three school children under the age of ten is overweight, if not obese, researchers said.
In the search for the cause of this phenomenon, foetal programming inside a mother's womb was put under scrutiny.
The hypothesis that the mother's diet might have some sort of influence could not be confirmed in the study by the Technical University of Munich (TUM) in Germany.
Administering a special diet rich in omega-3 fatty acids and low in arachidonic acid, an omega-6 fatty acid, to pregnant women neither resulted in children being slimmer nor fatter than their counterparts from the control group whose mothers had enjoyed a normal diet, researchers said.
It was believed that "bad" fats, especially omega-6 fatty acids, consumed during pregnancy increased the formation of infantile fat cells, while "good" omega-3 fatty acids protected the child against becoming overweight.
Since, in the animal model, an increased intake of omega-3 fatty acids during pregnancy and lactation coupled with a simultaneous reduction in arachidonic acids resulted in offspring with a significantly lower tendency to become overweight, the new human study was the first to investigate whether this result was translatable onto humans.
As many as 208 women with an average age of 32 years and a body mass index (BMI) of 22 took part in the study, which was aimed at verifying this hypothesis.
While half of the study group continued with a normal diet, the other 104-women-strong group ate an omega-3 rich diet coupled with a significant reduction in meat consumption (contains omega-6 fatty acids) from the twelfth week of pregnancy to the fourth month of lactation.
The children of the cohort mothers were examined once a year until the age of five, making this the first study to deliver valid data over such an extended period.
"We then examined the children using three different methods: firstly we measured their skin fold thickness, then ultrasound investigations were added as these are more accurate," said Hans Hauner from TUM.
"In one part of the cohort we also used MRS imaging to measure the fat inside the abdominal cavity," he said.
The end result was negative.
"This special diet had no effect on the weight of the babies and toddlers," said Hauner.
This proves that the earlier findings are not translatable onto humans and that the hoped-for benefit of such a diet is questionable as it does not appear to prevent childhood obesity, researchers said.
