Mouse pups from smaller litters—or those with better access to nutrition—developed more unhealthy, inflamed fat, new research shows.
When they were placed on a high-fat diet later in life, they developed an obesity profile that suggested an increased risk for diseases such as Type 2 diabetes and fatty liver disease.
The takeaway for humans is that infant nutrition between birth and weaning is a critical period for healthy development—not just for future obesity risk but also for risk of obesity-related diseases later in life.
“The human translation would be a parent overfeeding his or her baby, giving the baby more formula or other sugary beverages in the bottle, to keep the baby happy, or to get the baby to sleep,” says Michael I. Goran, professor of preventive medicine, physiology and biophysics, and pediatrics at the Keck School of Medicine at University of Southern California and director of the USC Childhood Obesity Research Center.
“We found that over-nutrition early on primed the fat in the mice to be more dysfunctional. They gained the same amount of fat as mice in larger litters, but the fat they gained was more metabolically dysfunctional.”
“Metabolically dysfunctional” fat could produce molecules and hormones that lead to systemic metabolic conditions including inflammation.
Scientists don’t know yet what causes the dysfunction, but it is known that about one third of obese Americans have more inflamed fat, which could be attributed to the way it develops in early life.
The next step in the research is to conduct a clinical trial in mothers and babies, Goran says.
The National Institutes of Health, the US Environmental Protection Agency, the Dr. Robert C. and Veronica Atkins endowed chair funds, and the European Union FP7 integrated project funded the work, which was published in the journal PLOS ONE.