A recent study titled Parental Obesity and Early Childhood Development, published in the Journal of Pediatrics showed mother’s and father’s who were obese themselves affected their child’s cognitive development.

From CNN:

Being overweight may impact not only your health but your future child’s development as well, a new study suggests.

Children of obese parents may be at risk for developmental delays.
In the United States, an estimated one in five women are obese when they get pregnant, registering a body mass index above 30. The healthy average is between 18.5 and 24.9.

But few studies have looked at the father’s weight, even though 20% to 30% of US adults — both male and female — are obese.

“Our study is one of the few that also includes information about fathers, and our results suggest that dad’s weight also has a significant influence on child development,” said lead researcher Dr. Edwina Yeung, an investigator at the institute.

“Obesity is correlated with a rise in inflammation and in hormones that regulate body fat and metabolism. One theory is that these hormones might influence the development of the baby’s brain,” Yeung said.

Other theories are that high blood sugar or a shortage of certain nutrients might influence brain development.

The effects of obesity in male sperm are also not sufficiently explained, but the developmental psychology expert says it is not impossible.

“It’s not a crazy idea. It has been speculated for some time that there may be distinct paternal genetic contributions to autism risk, for example,” he said.

The results of the study:

RESULTS: Compared with normal/underweight mothers (BMI <25), children of obese mothers (26% with BMI ≥30) had increased odds of having difficulties using small muscles, such as those in their fingers or hands. Paternal obesity (29%) was associated with increased risk of failing personal-social activities, such as feeding themselves, playing and undressing. Babies born to extremely obese couples also were more likely to fail problem-solving tests.

CONCLUSIONS: Findings suggest that maternal and paternal obesity are each associated with specific delays in early childhood development, emphasizing the importance of family information when screening child development.