I did a post today which dealt with the criticisms of the idea that insulin levels play a major role in obesity, which I felt weren't valid, and the author cited some material from obesity researcher Stephan Guyanet, who is a champion of the calories in and calories out theory, which of course places it in a position where it is opposed to the fat storage by way of too much insulin theory.
So we did touch on a few things in that post, but I wanted to look at this in more detail, and in particular, look at some more arguments by Guyamet. So he did an interview with Chris Kesser a while back, and I found the transcript on Kesser's site to use as a reference for this post to explore this thinking in a little more depth at least.
I do think that this is an important issue, especially since so many diabetics struggle with their weight, and so many non diabetics do as well. Obesity is exploding, it's an epidemic, in spite of a lot of people following the calorie expenditure model, so if this is the wrong approach, and we need to be looking at something else like high insulin levels or high carb intakes for instance, then we do want to make sure we're on the right track here.
This is a very long interview and I'll only be able to touch on a few points in this space, but feel free to check out the interview yourself.
What stands out the most for me, and we saw this in the last article as well, is that his view being correct relies on us basically assuming that his view is correct.
So he starts talking about thermostats and such in a way that leads us to believe that thermodynamics is behind all of this, as in burn more calories, lose more weight. That's what he needs to show though, whether this is true, not just to draw analogies to it assuming that it is.
He says that studies have shown that if you restrict calories you can produce fat loss. That's true, but how much fat loss are we talking about here? A few pounds, where the subjects may have been 250 pounds and now they are 245 or something? Also, when they cut calories, what macronutrients did they cut anyway? If they cut carbs well that's exactly in line with the insulin theory. So this comment tells us nothing.
He also mentions that when you allow the subjects to go back to eating what they want they gain it back and then some. This is well known, but when you let people of today eat what they want guess what they will be eating a lot of, being carb heads?
He does admit that exercise doesn't do much for us here but the reason given is that exercise doesn't burn anywhere near as many calories as we think. As well, people will tend to eat more calories when they exercise more. That's all true, but why do calories matter here? That's the question he needs to answer.
He then talks about thermodynamics, but what does thermodynamics have to do with body weight? If you are fat and you burn too much energy you will be both fat and tired. That's actually how it works.
Protein can put on muscle mass, carbs can certainly put on fat, and insulin is involved in both, but how does fat make you fat anyway? We can't just assume that because it is fat it makes you fat. We also can't assume that because we can derive energy from it, it will automatically be stored. It will if you have a lot of insulin though, which does explain the storage here, that's what he needs to do.
To his credit, he is a little critical of the calories in and out theory, but he needs to realize that he is also for the most part embracing it. He says that this cannot always explain the dynamics of energy balance, but once again, what does obesity have to do with energy balance anyway?
So he speculates that low carb diets are effective in weight loss because it resets the adipose mechanism. That's actually true, but the adipose mechanism here is insulin levels.
He does admit that insulin resistance is a major factor in obesity, but the fact is that when we look at people with insulin resistance we also see high insulin, which is known to be a major cause of it. So if you admit insulin resistance is a problem, and people with this have high insulin, and they get obese, and insulin is the hormone that regulates fat storage, well now you're on the right track.
He does speak of the gut flora causing inflammation and it's likely this plays a role in insulin resistance, and this is just one thing that causes inflammation although it may be a big one, but why is insulin resistance a problem in weight management? Well guess what, it's because it drives high insulin levels.
The interview goes on to talk about a number of other things, and it's certainly an interesting one overall and worth a read. The insulin theory of obesity survives unscathed though, this to me is like a preacher preaching to his flock, if you are a believer you will certainly give this all an amen, but this isn't convincing at all unless you already believe.