Eric Ravussin, Ph.D.

We don't need many because we need to homogenize the air in the room. I see, so that's the bigger effect. The room is the same as the other corners. That's why, but we have to measure humidity. You have to measure temperature because you have to do this correction, what we call STPD, which is standard pressure, et cetera, to calculate the energy generated by this oxygen.

We don't need many because we need to homogenize the air in the room. I see, so that's the bigger effect. The room is the same as the other corners. That's why, but we have to measure humidity. You have to measure temperature because you have to do this correction, what we call STPD, which is standard pressure, et cetera, to calculate the energy generated by this oxygen.

But yeah, I mean, it's quite phenomenal, the accuracy of those. And to go back to your question, the accuracy or the precision is about two and a half percent. Now, if you repeat yourself five times and myself, there's a little bit more variability because we vary from one day to another one. And so on.

But yeah, I mean, it's quite phenomenal, the accuracy of those. And to go back to your question, the accuracy or the precision is about two and a half percent. Now, if you repeat yourself five times and myself, there's a little bit more variability because we vary from one day to another one. And so on.

But I mean, this is quite amazing that we can calculate so precisely your energy expenditure during a day or two days and so on. I wish we had the same system to calculate the energy that we put in.

But I mean, this is quite amazing that we can calculate so precisely your energy expenditure during a day or two days and so on. I wish we had the same system to calculate the energy that we put in.

When it's in free living, it's worse. When you do that under supervision and you provide all the meals like Kevin Hall is doing, like we're doing, then you have a good estimate and you subtract what is returned on the plate or this kind of things. But it's not normal life. As soon as you go to normal life and free living conditions, things are falling apart.

When it's in free living, it's worse. When you do that under supervision and you provide all the meals like Kevin Hall is doing, like we're doing, then you have a good estimate and you subtract what is returned on the plate or this kind of things. But it's not normal life. As soon as you go to normal life and free living conditions, things are falling apart.

Yes, but on the other hand, if you take your lifetime history, maybe you're an exception, but I have gained some weight. When I got married in 1975, I weighed 69 kilos. Now I weigh close to 77. Now it's 50 years later, of course, but you have this change. You have also a change in your body composition. And it's very rare that people are staying the same constantly.

Yes, but on the other hand, if you take your lifetime history, maybe you're an exception, but I have gained some weight. When I got married in 1975, I weighed 69 kilos. Now I weigh close to 77. Now it's 50 years later, of course, but you have this change. You have also a change in your body composition. And it's very rare that people are staying the same constantly.

I mean, you may be an exception.

I mean, you may be an exception.

I think I had an answer. I hope that I had an answer, but I don't. You know, when leptin was discovered, it was a ha-ha moment. We have a signal which comes from the energy storage, and therefore, you know, it seems to regulate food intake, also energy expenditure and all that. I was fortunate to have access to

I think I had an answer. I hope that I had an answer, but I don't. You know, when leptin was discovered, it was a ha-ha moment. We have a signal which comes from the energy storage, and therefore, you know, it seems to regulate food intake, also energy expenditure and all that. I was fortunate to have access to

The three Turkish leptin deficient people that we measured in these chambers in Baton Rouge, we thought that we would have a clue, and it was not the case. We know that leptin is very good to defend against the loss of weight when it becomes extreme, but it doesn't work on the other side of the equation when you creep up.

The three Turkish leptin deficient people that we measured in these chambers in Baton Rouge, we thought that we would have a clue, and it was not the case. We know that leptin is very good to defend against the loss of weight when it becomes extreme, but it doesn't work on the other side of the equation when you creep up.

with your weight because you become leptin resistant and your leptin is not telling you stop to eat. I think that we learn a lot about the biology of energy balance thanks to leptin. But then we need to think that we have also signals coming from the fat-free mass. Now, what is the fat-free mass?

with your weight because you become leptin resistant and your leptin is not telling you stop to eat. I think that we learn a lot about the biology of energy balance thanks to leptin. But then we need to think that we have also signals coming from the fat-free mass. Now, what is the fat-free mass?

We measure it as everything but the fat, and we call that fat-free mass, but it's liver, it's skeletal muscle, it's everything but the fat. And I think that there are signals that we are still chasing. John Blundell showed that we eat according to our fat-free mass.

We measure it as everything but the fat, and we call that fat-free mass, but it's liver, it's skeletal muscle, it's everything but the fat. And I think that there are signals that we are still chasing. John Blundell showed that we eat according to our fat-free mass.