That's the conclusion of a new research, which has found that children exposed to pesticide in womb are twice as likely to be overweight.
According to the groundbreaking Spanish study, exposure to a range of common chemicals before birth sets up a baby to grow up stout, thus helping to drive the worldwide obesity epidemic.
The latest research is the first to link chemical contamination in the womb with one of the developing world's greatest and fastest-growing health crises.
According to scientists at Barcelona's Municipal Institute of Medical Research suggests that pollution may predispose people to get fat.
The research, published in the current issue of the journal Acta Paediatrica, measured levels of hexachlorobenzene (HCB), a pesticide, in the umbilical cords of 403 children born on the Spanish island of Menorca, from before birth.
It found that those with the highest levels were twice as likely to be obese when they reached the age of six and a half.
HCB, which was mainly used to treat seeds, has been banned internationally since the children were born, but its persistence ensures that it remains in the environment and gets into food.
The authors of the study suggest that unborn babies' exposure to pesticides should be "minimized", noting that other research has shown chemicals fed to pregnant animals can result in them having obese offspring.
Dr Pete Myers, one of the world's leading experts on obesogens, told The Independent: "This is very important. It is the first good study of the effects on the fetus. Its conclusions are not surprising, given what we know from the animal experiments, but it firmly links such chemicals to the biggest challenge facing public health today."
No one knows how HCB causes obesity. The Spanish scientists speculate that it may have made the mothers diabetic, which would increase the chances of their children becoming obese.