Considering the role of dietary fat in obesity and heart disease, why is bacon so dang yummy? After all, most poisons in nature taste horrible.

Utah State University biologist Tim Gilbertson will address this and other issues around junk-food cravings Friday when he gives the inaugural Science Unwrapped lecture at the Logan school. To understand unhealthy cravings, Gilbertson has turned to Charles Darwin's theory of natural selection.

Sugar and fat are rich sources of energy. In the past, those who ate and stored the most calories had the best chance of survival. Cravings for fat and sugar may been passed down through the generations, perhaps embedded in our genes, Gilbertson said.

"My research explores how the body recognizes dietary fat. We're challenging the notion that fat is tasteless," said Gilbertson, associate director of the Center for Advanced Nutrition. "Is there something in fat that activates our taste-detection mechanism?"

USU's College of Science founded the series to engage the local community in research being conducted at the Logan land-grant institution. Upcoming lectures address anatomy and astronomy.

"We want to portray science as a fun subject, but also we want to make it accessible to the public. We want families to bring kids," said science dean Mary Hubbard. "We will pick topics that are timely. This is an effort to take the brain power and the exciting science done here at USU, and unwrap what we're doing and make it accessible to the public."

The series is USU's version of the University of Utah's successful public lecture series, Frontiers of Science and Science Night Live. It will mostly showcase USU researchers, but the college will bring in ringers like University of Washington chemist Jeannie Rudzki Small, who will discuss epidemiology next month. One of Hubbard's goals is to promote the place of science in the public mind, which could help defuse many hot-button issues.

"They have been controversial because of a lack of understanding of science," she said. "We need a new generation of scientists to help solve problems and make discoveries."

Case in point: How can we use our knowledge of human evolution to turn around the obesity epidemic? Maybe it's all about the pleasure we get from eating, suggested Gilbertson, who will be joined Friday by USU wellness coordinator Caroline Shugart.

"One of the positive things and the negatives things about food is it's really rewarding," he said. Mouse studies suggest the more fat we eat, the less pleasure we derive from modest portions, leading to greater intake.

"There are important implications. There are parallels with drug addiction," Gilbertson said. "They have to eat more and more to get the same level of pleasure."

bmaffly@sltrib.com