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RS 189 - Stephan Guyenet on "What causes obesity?"

Release date: July 23rd, 2017

Stephan Guyenet

In this episode Julia sits down with neuroscientist and obesity researcher Stephan Guyenet, to talk about what scientists know so far about the causes of obesity, and in particular the brain's role in regulating weight gain. Julia and Stephan cover questions such as: Why did obesity start to increase in the United States in the latter half of the 20th century? Does the body have a "set point" of fat that it tries to defend, and what affects those set points? Are low-carb diets more effective for weight loss than low-fat diets, and if so, what explains the difference?

Stephan's Book: "The Hungry Brain"

Stephan's Pick: "Salt Sugar Fat: How the Food Giants Hooked Us" by Michael Moss

Edited by Brent Silk

Music by Miracles of Modern Science


Full Transcripts 

Reader Comments (20)

Heh, just in the last episode, I commented, "I'm glad that Julia pointed out that just because some evolved trait served our ancestors a million years ago, doesn't make it advantageous to us today. For example, our love of sugar and fat that now causes obesity..."
July 24, 2017 | Unregistered CommenterMax
1:04:00 It's certainly possible to retrain yourself when it comes to flavor. If you deprive yourself of certain foods for long enough, you will come to appreciate simpler foods more. I had to start a highly restrictive diet because of some GI issues, and after a few years I've reached the point where a nice orange is as rewarding to me now as a piece of chocolate cake was before. I can't tolerate garlic or onion, but after not eating them for years I no longer miss them. My expectations for flavor have been re-calibrated and milder flavors from herbs etc. will fill the void left by garlic and onions. Foods that were once dull have become more exciting.
July 24, 2017 | Unregistered CommenterTristan
I have always wondered whether our bodies have the ability to regulate the efficiency with which our digestive system acquires nutrients. Conventional wisdom is that we remove essentially all of the calories that enter our mouths, but one way for the body to maintain the theoretical set point would be to allow some calories to pass through if our weight is already optimal. I wonder if this has been explored.
July 26, 2017 | Unregistered Commenterjon bondy
quite interesting discussion

this medical condition that seems to violate thermodynamic law of intake/expenditure via NY Times Health
July 26, 2017 | Unregistered CommenterMad Max
Very interesting discussion, especially for an old fat guy that is struggling to understand how to reverse his trend. You're both correct - it's complicated! More discussion, please. Thanks ... Joe
July 26, 2017 | Unregistered CommenterJoe
Lose weight with AYDS! AYDS candy :-p
July 27, 2017 | Unregistered CommenterMax
What ever happened to this?
"Drug Activates Brown Fat and Increases Metabolism"
July 27, 2017 | Unregistered CommenterMax
jab harry met sejal review
It would be interesting to know why Stephan Guyenet was picked to talk about this? Just for the sake knowing his affiliations.
July 27, 2017 | Unregistered CommenterLouis
Sigh, looks like Guyenet is not familiar with the recent scientific challenge to the calorie model, though Julia tries to challenge it a bit at least. Many of Guyenet's core claims are contradicted by multiple controlled studies, like this one:
July 27, 2017 | Unregistered CommenterProf C
Food for thought... A year and a half ago I finally quit soda and greatly reduce my sugar and carb intake. I lost 10 lbs. after quitting soda (I didn't even have to exercise). Quitting soda was one of the hardest things I ever had to do. In the middle of quitting soda, I started to hear voices telling me... "You really want a soda now..." Not very rational at all…. Have you ever tried going to the supermarket to get something that doesn't have sugar or carbs? What gave me the extra drive to quit was the Audible Book, "The Power of Habit". I discovered that society, culture, politics, bad eating habits, work, irrationality, anger, etc. is all a habitual heuristic. We are all biological robots that need to be reprogrammed sometimes. I also have a feeling that industrialization and capitalism work ethic has robotized us a little too much and that is why America is too busy to stop reflect upon the irrationality of the our lifestyle.
July 28, 2017 | Unregistered CommenterDT
Would blame the drive for companies to sell more food. They make a lot more palatable food than 40 years ago. They find out exactly what makes us crave their product. They make the product a lot easier to cook. Still remember what a marvel it was to have our 1st microwave oven & when microwave popcorn 1st became widespread. It was truly awful by today's standards, but we could pile it on like never before. For the next 40 years they only evolved the formula & got all of the kernels to actually pop.
July 28, 2017 | Unregistered CommenterLion
I had a friend who discovered that her newborn child was allergic to a few things, among them gluten. In order to nurse the baby, she had to stop eating gluten for about 9 months. Her diet did not change in any other way, but she lost about 30 pounds while on the gluten free diet. And gained it back when she went back on gluten. Mysterious.
July 28, 2017 | Unregistered Commenterjon bondy
This was such a frustrating podcast episode. I feel Julia did a terrible job of holding Guyenet to account for all of the biases he displayed. She tried at the beginning: G. approached the issue of obesity with an oversimplified analogy taken from physics, the thermodynamic - energy in / energy out paradigm, even though this is WELL documented to be so oversimplified as to be practically useless in modeling obesity. Julia asks if his approach could account for the observed increase in obesity. Guyenet said, "well, some people are looking at that, but I am an neurologist so I look at it from a brain perspective". WHAT?? Translation: "No, I can't explain it, but I really feel that I SHOULD be right, so I'm going to keep talking." If your particular specialty is unable to explain observed phenomena ---- get a collaborator to supplement your expertise!! But, No. Guyenet is emotionally and professionally attached to the idea that the brain controls what we eat, and so he completely IGNORES the well documented hormonal mechanisms of metabolism (yes, it is more than just leptin) and the clear causal links of insulin to fat regulation. Astonishing!!

Surely the starting point of any scientist should be explaining the observed data.

Why did Julia not press him on this bias? Was it politeness? Is she unwilling to challenge the "Expert"? If this is so, then perhaps the whole format of the podcast is flawed. If she is unwilling or unable to recognize and call-out intellectual sloppiness of experts by herself, then perhaps a format where she moderates a discussion of two dissenting expert opinions would work better.

This episode is definitely NOT an example of rationality, and is well beyond the borderlands into the land of nonsense.
July 31, 2017 | Unregistered CommenterLeeAnn
Thank you for sharing this helpful discussion! This is what I need to know.
August 9, 2017 | Unregistered CommenterJulia
I really liked this discussion. I think the nutrition debate is starting to sound like a politics, and I found this conversation to be fairly balanced
October 4, 2017 | Unregistered CommenterMyshkin
I don't think anyone asked this question in the comments, and it didn't come up in the podcast. But I'd be interested in opinions. If people who try to lose weight face a problem because their brains are telling them to eat, plus there's a physiological response slowing down their metabolism, what about lean people who gain weight and then want (or not want) to lose it? Do their brains tell them to eat less and is there a physiological response speeding up their metabolism? In other words, does the so-called set point (which I think is Julia's word, not Stephen's) work both ways? Does it establish a desired weight and help you drop if your weight rises too high? Or is that too simplistic? I'm not sure, but I think people who have been anorexic a long time do not get very overweight?
October 21, 2017 | Unregistered CommenterEkai
Very interesting points. Now it's time for PIZZA !!
November 29, 2017 | Unregistered CommenterJameson
Actually, I was just eating some Pizza, and I thought of this episode. Guyenet claims that eating a liquid diet caused people to lose an average of 7 pounds over 2 weeks, due to the blandness and undesirability of the diet. However, I seriously doubt those people lost a total of 7 pounds of FAT. Most likely, on a full calorie liquid diet, they lost about 2 pounds of fat and 5 pounds of salt water, due to the osmotic effect of a low sodium liquid diet. As soon as they start eating normal foods, and consume the salt again, they will gain those 5 pounds back.

It therefore makes sense to eat a balanced diet, with plenty of protein, essential fat acids, vitamins and minerals, and not too many calories, whilst also having a good exercise regime including both anaerobic and aerobic exertion.
September 1, 2018 | Unregistered CommenterJameson
good job admin
February 20, 2019 | Unregistered Commenternadia

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