Body fat is a source of shame for many people, something to be hidden, fought, and burned away. But fat, says the biochemist Sylvia Tara, isn’t just unsightly blubber, it’s an essential and deeply misunderstood organ that’s vital to our existence. It enables our reproductive organs, strengthens our immune system, protects us from disease, and may even help us live longer. In her book, Tara explores the science behind our least appreciated organ, and she joins us Monday to talk about it.