Dr. Rhonda Patrick: What about—you’re talking about eating the whole foods versus the processed and junk food and bad stuff? What about people that are coming to you that are—there are so many different diets that are fad diets for weight loss. And if someone does want to lose weight, they want to increase their lean body mass and maybe body recomposition. And I know we're going to talk about training and stuff, but is there a calorie amount that you sort of start with? Is it based on their body weight? Like, is that something? Or do you, like, think about the actual composition? Are they doing low carb? Are they doing high carb, low fat? How do you approach that?

Dr. Layne Norton: So the most important thing is calorie intake. It’s energy intake versus what you're expending. But how you get there is what's really important. People can kind of conflate a physical law of thermodynamics with tracking calories. Those are not the same thing. Right? Like, I can say, like, it's a rule. I don't think anybody disagrees. If you want to save money, you got to earn more than you spend. But now keeping a budget can help facilitate that. But you don't have to keep a budget to save money. And just because you keep a budget doesn't mean you will save money. Right? So I kind of relate. I try to get people to understand and separate those two things. But yes, calories are the most important thing.

But what I try to do is, one, figure out, okay, approximately what are they expending per day? And the best way, in my opinion, to do that is if they have been tracking, okay, what are you eating now? In general, what’s your body weight doing? Right. Because if they're logging relatively accurately and their body weight's not changing, I mean, you can put whatever you want into a calorie calculator, but that is their maintenance calories, that is their energy expenditure. Right. And so I like to start there and then if people haven't been doing that, one nice trick I like to do, as you know, when you monitor behavior, behavior changes. And we know this, right, even down to, like, photons, right. So I'll say, okay, if you don't know it, would you just do me a favor?

Just track for the next three days. I don't want you to change anything. Don't change a single thing you're doing. In fact, if you're eating junk food or if you're eating what you think is too much, that's great. Then we have a bigger shovel. Like your energy expenditure is higher than we thought. We have a big shovel to dig you out with. Right. So please don't change anything. But what invariably happens is it's a very instructive experience for them because they'll start tracking and realize, oh, man, I was eating a lot more than I thought because I was having a bowl of ice cream that I was thinking was a serving and it was three. Or, I always tell people, if you ever want to be disappointed, weigh out a serving of peanut butter, if you want to be depressed. Or they see what they're consuming and they change their behavior already because they're tracking, because they're monitoring. If you look at studies, it's very consistent. People underreport their calorie intake by 30% to 50%.

Dr. Rhonda Patrick: Yeah.

Dr. Layne Norton: There’s a classic 1992 study in the New England Journal of Medicine. They had people who self-reportedly were weight loss resistant. So these people claimed that they were eating 1,200 calories a day. They specifically wanted this population. And these were obese people. And they said they put them in metabolic ward—so they're tracking their energy expenditure in a metabolic chamber, and they know exactly what they're eating. And they even told them, like, “We’ll know if you’re eating more than you say.”

And they also looked at lean mass, BMR, total energy expenditure. So what was really interesting, this was one of the first studies that showed that obese people didn't have slow metabolisms. And, like, at first, you know, the first few decades of us trying to deal with the obesity crisis was us, like, looking on the metabolism side: they must have slow metabolisms, or we've got to increase metabolic rate. And now we know it's the appetite side that has a much stronger effect on body weight regulation. I mean, it's so funny when people say to me, well, I have a slow metabolism. That's why I want to take Ozempic. I'm like, well, if you have a slow metabolism, Ozempic is not going to help because it doesn't increase your metabolic rate. It is a very powerful appetite suppressant.

So in this study, they looked at BMR, total energy expenditure, and found that basically, people's lean body mass explained about 70% to 80% of the variance in BMR and total energy expenditure. You can almost draw, like, a straight line through it.

Dr. Rhonda Patrick: Can you explain that to people? Because I think it’s important. Right. And that was kind of a follow-up question, is, like, well, where training comes into this picture, where muscle mass comes into this picture, and why? How is that a really important lever that you can pull to help people, like body recomposition, to help people lose fat?

Dr. Layne Norton: Yeah. So lean mass. Just to be clear, lean mass and skeletal muscle mass often get used interchangeably, and they're not. Lean mass is a relatively good proxy for skeletal muscle mass. But lean mass versus fat mass is a two-compartment model. Like for DEXA, for example, you'll get fat mass. So literally all fat tissue will go into a bucket, and then everything else goes into a bucket. So we're talking bone, skin, undigested food, fluid, like, all that kind of stuff. But in general, adipose is relatively—it’s not an inert tissue. We used to think it was inert tissue. We know that's not the case anymore, but it has a very low energy expenditure relative to other lean tissues. And actually, skeletal muscle doesn't have a super high energy expenditure for a lean tissue.

It's actually one of the slowest, if not the slowest. Like, liver and gut tissues have a much higher metabolic rate. But your skeletal muscle is your biggest overall lean tissue and I would argue your biggest organ. And so its effect—having an extra ten pounds of skeletal muscle because there is so much of it, it does have a profound effect on your energy expenditure overall. So when they looked in this study, when they standardized for lean mass, they saw basically no difference, no statistical difference in anybody’s metabolic rates or their total daily energy expenditure. And when they tracked their intake, what they found was they reported 1,200 calories a day, but on average they were consuming about just over 1,800. And they also overreported their physical activity by 47%.

Now, I think a lot of people will look at that and go—so when I present that data, a lot of people get really upset because no one likes being called a liar. I don't think people are lying. I don't think that's what it is. I think we look at ourselves with rose-colored glasses and we look at serving sizes and we tend to just give ourselves a little more grace than we probably should. Even yesterday, I did a day of eating while I was traveling and I showed that I went out to lunch, I got a salad, grilled chicken. I said, can you put the dressing on the side? Put the cheese on the side, right? And I just used a little bit of cheese. I used the dressing. But still, like, after I added everything up, I'm like, there's over 30 grams of fat in the salad.

A lot of you guys would have the salad and think, oh, this is low-calorie, right? No, the salad was 600 calories, you know. And then look at, for example, The Cheesecake Factory, you look at the salads are well over 1,000 calories. I think many people do think they're eating healthy and just don't really have a great understanding of how quickly energy can add up if you're not very mindful about it.