Obesity related diseases may have more to do with prenatal factors than overeating and lack of exercise, The New York Times reported early this month.

Recent studies show that unwarranted weight gain during pregnancy often results in larger-than-normal infants who are predisposed to become obese children and adults later in life. These individuals were also more inclined to develop diabetes, heart disease, and cancer.

According to Dr. Sylvia R. Karasu and Dr. T. Bryam Karasu, in their book The Gravity of Weight, “fewer than 40 percent of pregnant women gain only the recommended amount of weight during their pregnancy.”

The fact that women are beginning their pregnancies fatter than ever before is also contributing to the increased instances of overweight babies. A joint study conducted by Dr. Janet Currie from Columbia University and Dr. David S. Ludwig from the Children’s Hospital in Boston revealed a consistent link between the weight a woman gained during her pregnancy and her baby’s birth weight.

“There’s no reason for a woman to gain more than 40 pounds with a single baby. We used to think babies in the womb were well protected, but we now know they are influenced by lots of things that will affect them later in life,” Dr. Currie said. “The next frontier has to be the pre-pregnancy period. If we really want to improve the health of children, we have to get to mothers before they get pregnant.”

For a list of recommendations regarding pregnancy weight gain, view the Institute of Medicine’s suggestions at iom.edu.