In a fourth study, researchers have been attempting to get even closer to a human model by looking at primates. Dr. Kjersti Aagaard-Tillery of Baylor College in Houston, Texas, and colleagues studied macaques given a 35 percent high-fat diet.
Some of the animals became obese as a result of the diet, while others did not. But of those who became pregnant, all gave birth to offspring that developed non-alcoholic fatty liver disease and high levels of fats known as triglycerides in the blood.
"It is clear that changes to diet, glucose levels in the mother, and vitamin intake, prior to ovulation and conception can have long-term effects on fetal growth and adolescent and adult disease," Moley said.
However, she cautioned women to restrain their worry, because the researchers aren't certain of the timing surrounding these events.
"[Egg cells] are constantly being turned over," she said. "The key is to maintain adequate metabolic control for about three months prior to attempts at conception."
Shuk-mei Ho of the University of Cincinnati, who also presented data on the subject, said that similar effects in fathers should be noted as well.
"The contribution of paternal influences is very important," Ho said.