New York: In a warning to soon-to-be mothers, researchers have recommended healthy and nutritious food during pregnancy as excess weight and high blood sugar can make babies prone to childhood obesity. Being overweight with elevated blood sugar affects the baby's metabolism in the womb. "When women have elevated blood sugar and gain excess weight during pregnancy, it seems to change the baby's metabolism to 'imprint' the baby for childhood obesity," claimed lead study author Teresa Hillier from Kaiser Permanente Centre for Health Research in the US. "We're not sure yet of the exact mechanism of this change but it appears that the baby is adapting to an overfed environment whether from glucose or extra weight," said Hillier in the paper published in the journal Maternal and Child Health Journal. The team analysed more than 24,000 mothers who gave birth to normal weight babies of 2.5 to four kgs at birth and were accessed between 1995 and 2003. The findings indicated that children of mothers who had elevated blood sugar during pregnancy were at higher risk for childhood obesity. Those children were 30 percent more likely to be overweight or obese between ages two and 10 compared to children whose mothers had normal blood sugar. Mothers who gained 18 Kg or more during pregnancy were 15 percent more likely to be overweight or obese. "We need to intervene during the mom's pregnancy to help her with nutritional and lifestyle changes that will result in healthy weight gain, healthy blood sugar and ultimately, healthy children," Hillier stated.