Can your grandfather’s eating habits affect your likelihood for obesity?

Inheriting grandpa’s ears may be the least of a young man’s worries.

A new study suggests the propensity to become obese may be passed down from grandfather to child to grandchild. According to the study’s findings, if men were obese and eating poorly at the time of conception, their sons and grandsons may be at higher risk to become obese later in life.

This means sons and grandsons who consume a high-fat, high-sugar diet may accelerate the development of fatty liver disease and pre-diabetic symptoms, such as elevated glucose and insulin in the bloodstream, predisposing them to obesity and obesity-related diseases such as type 2 diabetes and liver disease.

Scientists are unsure exactly how this male multi-generational predisposition works, but believe the answer may lie in the sperm.

“We tend to focus a lot on mom’s health and diet during pregnancy, but don’t often consider the impact dad’s health might have on the child,” says Dr. Christine Mueller, a family medicine physician at Advocate Sherman Hospital in Elgin, Ill. “This research is just one more piece of the puzzle in trying to understand the many genetic and environmental factors that influence health.”

It also may help explain why the cycle of obesity is so challenging to break. According to the CDC, more that 37 percent of U.S. adults and 17 percent of children and adolescents are obese. Obesity-related conditions include heart disease, stroke, type 2 diabetes and certain types of cancer, some of the leading causes of preventable death.

The study does suggest some good news, however. Great-grandsons did not exhibit as high of a propensity to develop metabolic diseases, despite the health state of their father, grandfather and great-grandfather at the time of conception.

“Increased interest among Millennials in health and wellness is promising,” says Dr. Mueller. “Though this study may suggest male Millennials with a family history of obesity may be challenged to maintain good health, they may also play a role in breaking the cycle of obesity for their children and grandchildren.”