Excess fat consumption during pregnancy is shown to increase type 2 diabetes risk in future generation

Obesity during pregnancy is known to increase a child’s future chance of being overweight and developing type 2 diabetes. However, a new study from a team of University of Illinois researchers suggests that a fatty diet during pregnancy may be just as great a risk as excess weight.

The investigators reported in the Journal of Physiology that a high-fat diet during gestation can lead to genetic changes in developing infants that cause their livers to produce high levels of glucose. This occurrence may precede insulin resistance and type 2 diabetes.

Findings from the study are particularly pressing, the researchers said, because they show that a diet consisting of 45 percent fat is sufficient to cause these genetic changes. This type of diet has become common throughout the Western world, and many women are likely to consume these high levels of fat during pregnancy.

"In recent years, the American diet has shifted to include many high-energy, high-fat, cafeteria-type, and fast foods," said Yuan-Xiang Pan, a professor at the University of Illinois who participated in the study. "We found that exposure to a high-fat diet before birth modifies gene expression in the livers of offspring so they are more likely to overproduce glucose, which can cause early insulin resistance and diabetes."

For the study, researchers fed a set of mice either a high-fat, Western-style diet or normal rodent feed. The offspring of the mice in the high-fat group were found to have blood sugar levels that were twice as high at birth as those in the control group. Further genetic testing revealed the DNA alterations that caused the liver to overproduce glucose.

Aside from underscoring for women the importance of maintaining a healthy diet during pregnancy, the researchers said that their findings may also point to methods of diagnosing those who are at risk of developing type 2 diabetes at a young age.

The types of genetic changes that cause the liver to produce too much glucose leave behind markers that could be easily tested for. By allowing doctors to assess a person’s type 2 diabetes risk early in life, health professionals may be able to recommend diets and lifestyle habits that reduce the risk of metabolic problems.

Furthermore, the findings could suggest new strategies for obstetric care. Pan said that women are commonly cautioned against gaining too much weight during pregnancy, but they are rarely given any specific nutritional guidance.

However, counseling individuals against consuming excess saturated fat may result in healthier pregnancies. In particular, replacing less healthy types of fats with more beneficial omega-3 fatty acids could lead to a reduced risk of type 2 diabetes in offspring.

"Until now we didn't realize that a mother's diet during pregnancy had a long-term effect on the metabolic pathways that affect her child's glucose production," Pan said. "Now that we know this, we urge pregnant women to eat a balanced low-fat diet that follows government guidelines. Then a woman can prime her child for a healthy life instead of future medical struggles."