The fat hormone leptin may explain the link between poorly nourished pregnant women and an increased risk for obesity in their children, according to Japanese researchers.

A premature surge of leptin in newborn mice delivered by underfed mothers resulted in a change to important brain circuits controlling energy regulation, researchers at the Kyoto University Graduate School of Medicine report.

This change appears to contribute to obesity later in life, they said, since the early rush of leptin seemed to trigger accelerated weight gain in the mice offspring.

Leptin, a hormone produced by fat, normally decreases food intake while increasing energy output. Earlier mouse studies have found that a lack of leptin or a resistance to its effects is highly associated with an increased risk for obesity.

"Obesity has increased at an alarming rate in Western countries and is now a worldwide public health problem. Genetic and environmental factors, such as a high-calorie diet, are thought to contribute to the prevalence of obesity," lead researcher Shingo Fujii said in a prepared statement.

Targeting this premature leptin surge could yield new treatments against obesity, the researchers add.

The study is published in the June issue of Cell Metabolism.