Researchers from the Hospital for Sick Children, Toronto, Canada have been cautioning pregnant women not to smoke or stop if they are into the habit of the same, a report has unveiled recently.

The warnings are being seen after a discovery that smoking can risk children at becoming obese at some stage of their life. The study is the first of its kind since, smoking at the time of pregnancy has already been proved to be linked with premature delivery of baby or low birthweight.

'Prenatal exposure to maternal cigarette smoking may promote obesity by enhancing dietary preference for fat, which may be mediated in part through subtle structural variations in the amygdala', said Dr. Amirreza Haghighi and colleagues.

The study published online in the Archives of General Psychiatry journal had recruited some 378 adolescents of ages 13 to 19 years. Almost half of them were the ones whose mothers had smoked during pregnancy. Comparing them with their counterparts, it was concluded that the former group were breastfed for bouts and weighed less at birth.

The reason, the report says, is that structural variations take place in unborn babies’ growing brains, which make them eat fatty foods, becoming obese. Thus, cutting smoking is also being included the in the government's tobacco control plan.