Why do our bodies hold on to fat despite diets? How can genetics, microbes and even viruses affect how much we weigh?
Sylvia Tara (@SylviaTaraPhD) explores those questions and others in "The Secret Life of Fat: The Science Behind the Body's Least Understood Organ and What It Means For You," and joins Here & Now's Jeremy Hobson to talk about the book.
On periods in history when fat wasn't hated
"There was a time in U.S. history where fat was actually quite loved and valued. After the Civil War, there was poverty, and there was destruction, and food was hard to come by. And those who had fat were considered privileged and beautiful, and people tried to look like they had fat. And it wasn't until later, until the economy got a little bit better, food was more available, people started gaining weight again. And that's where there were some warnings from military, from business, from politicians about the nation's growing girth."
On what made people fear fat
"It used to be only the select few could afford to have it. Then all of a sudden, when everyone's getting it, people just got a little bit wary of that, that it's now catching on with everybody. And it created a little bit of an echo chamber, this worry about fat — I mean even doctors previously had thought fat was not so bad, and they actually advised fat for helping with contagious disease, helping with nervousness. And it all just changed when it got to be where a lot of people could have it.
"And what happened then is that another voice in the chorus against fat happened to be businesses, entrepreneurs, hucksters who saw this great way to sell all kinds of gimmicks to people who were afraid of fat now. Odd things came in — the tapeworm diet, where people would ingest tapeworm eggs so that the tapeworms would siphon off calories, Fatoff, reducing soap that was supposed to melt fat under the skin. There was all kinds of ways to make money. And the advertising of these products became another really strong voice in the chorus against fat, to the point now where we have multi-billion dollar corporations going at this, we spend $60 billion or more on the fight against fat — more than we spend on the war on terror. I think if we're going to spend this much money on fat, we're going to target weapons against it, we have to really understand this enemy that we're fighting, and fat is much more than just a reserve of calories. It's actually quite sophisticated."
"Fat is vital to life, and because fat is so important, nature tries to protect it."Sylvia Tara
On fat's role and importance within the body
"Fat is actually an endocrine organ. It produces a number of hormones in our body that our body needs. One of these that's really important is leptin, and leptin has vast effects within our body. I mean, fat is tied to brain size, to brain health, it's tied to strong bones, it's tied to our reproduction system and conception, even. And so when people lose too much weight, women particularly... they actually can't reproduce. Fat is vital to life, and because fat is so important, nature tries to protect it. And through leptin, again, one of the effects is leptin has a very strong, direct link to appetite. So when we have a good amount of leptin, we feel pretty satiated, and our metabolism's pretty strong. But when we lose fat, because fat produced leptin, we lose leptin, too. And with lower leptin, our appetites shoot through the roof, our metabolism gets lower, and in that way, fat fights, our bodies fight to keep fat on us, to get it back."
On her goals in writing the book
"Part of what I'm hoping to do with this book is just help people identify... take away some of the fat shaming, the guilt around fat. It's not just sloth and gluttony, there's a number of ways we get fat. There are genetics, there are viruses, there are bacteria, gender plays a role, and our hormones play a role, and you have to consider all of these things when you're trying to lose weight. You might not be eating more than your neighbor, but you might have more fat, and don't feel guilty — it's not because you're failing at your diet, it's because you have to understand your fat."
Book Excerpt: 'The Secret Life Of Fat'
By Sylvia Tara
Excerpted from THE SECRET LIFE OF FAT by Sylvia Tara, PhD. Copyright © 2017 by Sylvia Tara. With permission of the publisher, W. W. Norton & Company, Inc. All rights reserved.
This segment aired on January 9, 2017.