Chris Kresser: I did see it, and it’s exactly in line with what I’ve been arguing for years now, which is that I don’t believe in the insulin-carbohydrate hypothesis of obesity. I’ve interviewed Stephan Guyenet, I think, three times on my podcast. I think he was one of the first guests I ever had on my show, and I’ve had him at least twice since then on the show, and he’s been a vocal opponent of the insulin-carbohydrate hypothesis of obesity. If you’ve followed that argument at all, you know that he and Gary Taubes have been at odds over the course of many years on that subject. I have always been more impressed with the arguments of researchers in the field, which include Stephan, although he’s no longer an academic. I’ve just never found the insulin hypothesis to be compelling for all of the reasons that Dr. Guyenet has outlined, and this is just another nail in the coffin, in my opinion, this latest finding. It’s particularly relevant and interesting because the study was funded by NuSI, and I’m sure the results are not what Gary Taubes and other proponents of that hypothesis were hoping for.
If you have any specific questions, let me know, but overall it’s in accordance with what I’ve believed about obesity for a long time. In short, it’s that obesity is caused primarily by an interaction between our modern lifestyle and our genetic predisposition. If you look at calorie intake over the past 30 or 40 years, which has coincided with rise of the obesity epidemic, it’s gone up right along with the rise in obesity, and it’s the highly palatable, highly rewarding—and I use that term in the sense of how it’s used in the psychological literature. Something that’s rewarding is something that makes us want to do more of it. This highly palatable, highly rewarding food that we are exposed to in the modern food environment causes us to overeat and gain weight, and then gaining weight causes insulin resistance and leptin resistance and other problems. Certainly there are exceptions. There are lean people who have insulin resistance, but as a general rule, I think that’s how it happens.
What’s important to realize is that the amount of overeating that happens is extremely small and really kind of imperceptible. I think one of the reasons people push back against that hypothesis is because it can lead to feelings of shame or guilt in people who are overweight because the implication is that they’re somehow gluttonous and have eaten themselves into that state, but that’s really not a fair assessment of that theory. If the overeating is just a matter typically of 100 calories or less, if you put two plates next to each other and they only differ by 100 calories, you wouldn’t be able to visually tell the difference between the two. We have a hedonic and homeostatic system for regulating weight that is so unbelievably fine tuned that it is able to differentiate between those 100 calories in a way that we could never do just looking at a plate of food. So when that system goes off, it can lead to overeating, and it has nothing to do with gluttony. It’s barely, barely perceptible, but over many, many days and many weeks and then many months and years, it adds up, and it can add up to 10, 20, 30, 40, 50, 60 pounds of overweight.
I think I’ve covered this in quite a bit of detail in other places, so I’m not going to continue to be on this because we have a lot of questions, but go listen to those podcasts with Dr. Guyenet if you haven’t already. They’re really enlightening, I think.
- Stephan Guyenet on Causes and Treatment of Obesity—May 18, 2010
- Stephan Guyenet on Food Reward and Weight Loss—May 24, 2011
- Why It’s So Hard to Lose Weight—And Keep It Off—January 25, 2012
- What Research Says About Losing Weight and Keeping It Off—January 16, 2013