Eric Ravussin, Ph.D.

and you deplete from substrate or energy substrate your circulation and it puts you in a state of semi-starvation, what is happening when it goes to the brain when you have semi-starvation, you shut down your energy expenditure and you increase your appetite. And this was playing with that, saying that now if we switch to a diet which is going to be less conducive to storage, i.e.

and you deplete from substrate or energy substrate your circulation and it puts you in a state of semi-starvation, what is happening when it goes to the brain when you have semi-starvation, you shut down your energy expenditure and you increase your appetite. And this was playing with that, saying that now if we switch to a diet which is going to be less conducive to storage, i.e.

less insulin secretion, because he was less than 10% carbohydrate, between 5% and 10%, if I recall correctly, we would cause this, basically, this semi-starvation condition in the systemic circulation. And this would basically increase your energy expenditure. And I think that David Ludwig at the time had some data already showing by doubly labeled water that there was an increase.

less insulin secretion, because he was less than 10% carbohydrate, between 5% and 10%, if I recall correctly, we would cause this, basically, this semi-starvation condition in the systemic circulation. And this would basically increase your energy expenditure. And I think that David Ludwig at the time had some data already showing by doubly labeled water that there was an increase.

But we are arguing that doubly labeled water is not precise enough. It goes back to our discussion about indirect calorimetry. And we said, why don't we do it in the confinement of a metabolic chamber? And this is what we did.

But we are arguing that doubly labeled water is not precise enough. It goes back to our discussion about indirect calorimetry. And we said, why don't we do it in the confinement of a metabolic chamber? And this is what we did.

And to my surprise, there was an increase at least early because we had couples of, I didn't go back to the papers, but we had measurements every week for two days, if I recall correctly, for the four weeks. And the first week and maybe the second week, there was an increase which was significantly higher. in sleeping metabolic rate as well as 24-hour energy expenditure under the ketogenic diet.

And to my surprise, there was an increase at least early because we had couples of, I didn't go back to the papers, but we had measurements every week for two days, if I recall correctly, for the four weeks. And the first week and maybe the second week, there was an increase which was significantly higher. in sleeping metabolic rate as well as 24-hour energy expenditure under the ketogenic diet.

And boom, yes, there is an increase. Now, was it a significant physiological increase? I mean, we can argue about that. When we talk about metabolic adaptation, because people are talking about that now, we always say we need at least 150 calories. In the study, we achieved statistical significance, but it was just above 100 calories per day. And I was surprised myself of that.

And boom, yes, there is an increase. Now, was it a significant physiological increase? I mean, we can argue about that. When we talk about metabolic adaptation, because people are talking about that now, we always say we need at least 150 calories. In the study, we achieved statistical significance, but it was just above 100 calories per day. And I was surprised myself of that.

Now, we didn't measure the appetite of the people. I mean, were they less hungry under the ketogenic diet? Now, it brings us to all the weight loss studies which have been done either with a low-fat diet or low-carbohydrate diet. If you do a meta-analysis, it seems that there is a slight advantage to the ketogenic diet for the weight loss period.

Now, we didn't measure the appetite of the people. I mean, were they less hungry under the ketogenic diet? Now, it brings us to all the weight loss studies which have been done either with a low-fat diet or low-carbohydrate diet. If you do a meta-analysis, it seems that there is a slight advantage to the ketogenic diet for the weight loss period.

Basically, I was surprised and I was, as a Swiss, I was kind of a little bit more neutral sometime rather than the two camps, the red and the blue. I was surprised that there was this effect, but it disappeared at the fourth week or the third and the fourth week.

Basically, I was surprised and I was, as a Swiss, I was kind of a little bit more neutral sometime rather than the two camps, the red and the blue. I was surprised that there was this effect, but it disappeared at the fourth week or the third and the fourth week.

We had sleeping metabolic rate of 24 hours.

We had sleeping metabolic rate of 24 hours.

I wish I had an answer. I mean, I'm tortured between very well-controlled studies we do, like Kevin Hall does, where you basically domicile the people, you feed them whatever you want, you know exactly what you feed them, and you look at outcomes. I mean, I like that, but then how do you transpose that in real life?

I wish I had an answer. I mean, I'm tortured between very well-controlled studies we do, like Kevin Hall does, where you basically domicile the people, you feed them whatever you want, you know exactly what you feed them, and you look at outcomes. I mean, I like that, but then how do you transpose that in real life?

And one of my mentor was JP Flat, and JP Flat says, obesity scientists, they have a tendency to either look at the expenditure side of the equation or the energy intake, but they never put the two together. And he was right, because a lot of studies, you have an outcome which is on this side or on this side, and you maintain the other one.

And one of my mentor was JP Flat, and JP Flat says, obesity scientists, they have a tendency to either look at the expenditure side of the equation or the energy intake, but they never put the two together. And he was right, because a lot of studies, you have an outcome which is on this side or on this side, and you maintain the other one.