Claire Maldarelli, Assistant Editor at PopSci, discusses the publication's labeling of January as "Fat Month," where they help readers understand fat's impact on the human body as people embark on New Year's resolutions to get fit.

Maldarelli breaks down the differences in brown fat and white fat, digging into the role brown fat plays in helping burn up white fats. We talk about what happens when you lose and gain weight. Also, Maldarelli tells us about the surprising 2014 study that finds most white fat exits the body through the respiratory system.