If long-term dieting were simple, just about everyone with a weight problem would be in better shape.

But obesity and weight reduction are affected by complex molecular and cellular processes that need to be better understood.

An obesity research team within the University of Nebraska system has won a second round of National Institutes of Health money, $11 million, to study those molecular processes over the next five years.

The center’s name indicates the complexity of its work — the Nebraska Center for the Prevention of Obesity Diseases through Dietary Molecules.

Janos Zempleni, director of the center and professor of molecular nutrition at the University of Nebraska-Lincoln, said about 50 professors in the NU system are attacking the problem in various ways. The center won its first round of about $11 million from the NIH five years ago.

Some researchers aim to address fetal problems that can lead to obesity. Others seek to tweak foods packaged for diet programs in such a way that taste and texture aren’t affected.

“It’s a fun place to be,” Zempleni said Monday. The center’s headquarters are at Zempleni’s office in Leverton Hall on UNL’s East Campus. The word “center” refers to the team of researchers and not a physical place.

Researchers from the NU Medical Center and the University of Nebraska at Omaha are involved.

Researchers from many disciplines are involved, including nutrition, biochemistry, animal science, public health, molecular biology, statistics and others.

“It’s really a very diverse group,” he said.

One area of investigation indicates that poor diet, smoking or drug use by a pregnant woman can compel the fetus to conserve nutrients. But if the baby is then born into an environment with plenty of nutrition, the fetal adaptation can contribute to obesity.

Another looks at reducing fatty acids that store energy and cause weight gain and increasing fatty acids that burn energy and fat. Foods such as salmon and mackerel are helpful and lard is not, Zempleni said.

Obesity is a global problem, he said, and the U.S. is among the most challenged.

About one-third of Americans are overweight, he said, and another third are obese. The causes vary.

The trend started about 40 years ago, he said, with more sedentary lifestyles, a passion for fast food and eating out, less walking and more driving, and outdoors activities losing out to television and computer time.