Omar Eldakar PhD - Decoding Our Ancestral Appetite: The Evolutionary Roots of Obesity and Exercise Aversion

Unlock the secrets of our evolutionary past and discover why modern convenience is a double-edged sword in the battle of the bulge. With the expertise of Dr. Eldakar steeped in human evolution research, he navigates the perplexing reasons our bodies hoard fat with ease yet begrudge every ounce of muscle. This seminar is an eye-opening journey through the biological underpinnings of our instinctual drive for energy conservation—a survival trait that now plays out as a relentless struggle with weight in an age where elevators trump stairs and fast food is just around the corner.

Dr. Omar Tonsi Eldakar is an evolutionary biologist and Associate Professor in the Department of Biological Sciences at NSU Florida. Dr. Eldakar earned his PhD from Binghamton University and was a postdoctoral fellow at the Center for Insect Science at the University of Arizona. He maintains diverse research interests in adaptive behavior and physiology ranging from sexual conflict in insects, cooperation and conflict in bacteria, contagious and spontaneous yawning, to human evolution and athletic performance.

Transcript

Speaker 1: 0:00

All right, thank you for the introduction. So I'm not going to be presenting a research talk like Safiya and others just have. I'm more or less going to present more of a perspective kind of talk. And this is because every now and then I'll just be chatting with Jose and we'll get on a certain topic and he'll be like hey, yeah, yeah, can you just say that like in front of the for the ISSN people and I go, yeah, sure. So pretty much this is again is inspired from some conversations with with Jose is actually not something I directly research, even though I do research a bit of human evolution. All right, so, yeah, so why is it difficult to gain muscle and easy to get fat and why an evolutionary perspective can actually shed some, some insights on this? So this, this idea of this talk, really kind of came about, one because Jose asked me to do it and also because one time I was actually not that long ago I was walking leaving a grocery store this is public downtown Fort Lauderdale and I'm carrying my grocery bags up the stairs and then a homeless guy leans over the railing, wherever that arrow is pointing, and says why are you taking the stairs? Why don't you just take the elevator. And then I kind of pause for a second and I look at them and I say, well, because if I take the easy way now and I take the elevator now, I got to go out of my way to go to a gym and say use a treadmill. By the way, you guys might not know that treadmills were invented to actually torture people. So yes, if you go to the gym and you use a treadmill, you voluntarily just tortured yourself. So I said you know what? I think I'll just rather carry my food up the steps. You know, despite it looking strange, at least I'm carrying food right.

Speaker 1: 1:46

But that whole scenario it kind of made a few ideas kind of come to mind. A few thoughts came to mind and the first is well, you know, maybe this homeless person, you know, obviously they're on a, they're probably on a calorie restricted diet, not intentionally, but the calories coming in is, it's uncertain. So if you have uncertain calories coming in, then don't waste energy, you know. Don't, don't take the stairs. It would probably seem very odd for someone in that situation to you want to take the stairs and probably eat everything your hands on too. Particularly you want probably calorie dense foods. Again, you're thinking that this individual, essentially behaving adaptively like you would think someone would if they were stranded on a deserted island. They're not going to wake up and do their burpees or go for a 5k. They're going to say you know what? I'm not, I don't know when my next meal is coming, so I should really be as lazy as possible and only expend energy when I absolutely have to. So the second, oh, and also, we noticed that these individuals, you know, when you're on an uncertain sort of calorie diet or an environment with uncertain calories coming in, you'd expect that, you know, you would again try to minimize effort and try to maximize calorie dense foods. But we even get this when we're overweight. And when you're overweight, you literally have a surplus of energy, a surplus of calories, yet you still get this behavior.

Speaker 1: 3:05

Another thought that really came to mind is we're actually making the world easier to live in. It's probably not the best you know scientific comparison here, but the you can really correlate the number of elevators and escalators in service with actual obesity. I mean you could also correlate climate change with the decrease of pirates. So it doesn't mean it's exactly, you know, cause of, cause of, but ultimately elevators and escalators in use might be a good sort of indicator and how essentially physically easy life is getting. So if you have the same amount of calories coming in but life physically is getting easier and easier, you should expect larger humans and again things like obesity to kind of ring along.

Speaker 1: 3:49

So again, a third idea again that popped in my mind during that time was like a lot of the things around us, seeing these things around us as people, not knowing what answers are, the language addition who is, you know, hearing about things around them? Okay, well, that means if we invent things like elevators, then we have to use other things that we invent for, like torture, to try to counteract that. So we kind of got ourselves in this mess, because the same adaptations that make you want to take the elevator, that make you want to invent an elevator, are the same ones that make you not want to exercise to begin with. So we're becoming increasingly dependent on exercise and that is the one thing that our body simply does not want to do. And if you tie all these instances together, we really kind of start realizing that we're in quite a mismatch with our environment. We seem to be living in an environment with bodies that don't really match the conditions.

Speaker 1: 4:36

So another way of thinking about this is even a little goldfish hanging out in a bowl. Right, if you just keep dumping food in that goldfish bowl, the goldfish is going to keep eating and eating and eating. And you keep putting food in there, it's going to keep eating and eating until it dies and you just can go. Why did it do that? Is the goldfish an idiot, you know? And you go no, it's actually very well adapted. It's just well adapted to avoid under eating because in its natural environment it was extremely unlikely to overeat but it was way more likely to under eat. So you're more likely to die from a calorie deficit, you're more likely to die faster from a calorie deficit and it's also going to impact your ability to survive and, obviously, reproduce. So you should obviously, as animals, adapt it to avoid deficits, not to essentially avoid surplus.

Speaker 1: 5:25

So what is actually shaping this animal to its environment? Well, that's natural selection. So we got to get a quick little review of natural selection before we can really understand again. What's this force that's shaping our bodies, that has shaped our bodies in the past? Well, natural selection is really simple. I can explain it with just one slide, so if you have variation in a population like these beetles right, some of them are green and let's say, some tan ones emerged right Now if these tan ones have a certain advantage because they're kind of camouflaged in the background, then they're more likely to survive and reproduce than the green ones. So you'd expect that there'd be more and more and more tan ones every generation, because the tan ones are more likely to survive, they're more likely to have offspring and the offspring are more likely to resemble them. And you can imagine if another mutation popped up that made them even more camouflaged, then that would also provide a survival and reproductive advantage and increase in frequency over time. If the background of the environment changed to green, you'd expect it to go in the other direction.

Speaker 1: 6:27

The idea is natural selection is helping fashion organisms to better match their environment. So we have to understand what environment really, what the environment was like when that was shaping our bodies. So we can think of other examples of natural selection, other traits we can explain really quickly. I used this last year when I talked to this group. I said well, why does sex feel good? It's pretty easy to understand evolutionarily, because if it feels good you want to do it more. And if you do it more you're going to lead more, you're going to have more offspring, right, compared to individuals where it doesn't feel so good or individuals where it feels absolutely terrible. So you can imagine that's, that's why sex actually feels good and that's why other animals will essentially walk into traffic or walk right in front of a hunter to get access to it, because they want it so badly. And you could again see why it makes sense. And again, to point out this notion of mismatch, just because we have things like birth control now so that sex doesn't lead to offspring, it doesn't mean the desire for sex goes away. It's still, again, an adaptation for a different environment. So if you change the environment, you're not going to automatically change the expression of a certain trait.

Speaker 1: 7:37

Why do we feel pain? Again, quite obvious Pain avoids it, protects your body from injury. It might suck to feel pain but ultimately if you're feeling the fire is getting kind of hot, well good, it should hurt. So you get away from it, as opposed to sort of melting yourself and being injured. Right, if you say, twist your ankle as a hunter-gatherer you shouldn't run on that until it starts feeling better. Then you run on it right. That pain is telling you this thing's not ready yet you know. So it can prevent re-injury.

Speaker 1: 8:05

It's also a very powerful motivator for learning, as you know some of the older generation how they learned from their parents, right, and also I mean it's a great stimulus. You get physically punished for something. You remember that and you learn from it. If you ate a berry and it just had a horrible, a wreaked havoc on your guts, you're going to remember that and you're going to avoid it. If you get stung by bees, you're going to make those things hurt and you're going to avoid them. So it helps you learn and behave adaptively. That's why individuals that don't feel pain rarely make it past the age of 30. Because while they're playing as little children, they might cut themselves and they just keep on with their hands in the mud and they can actually most often die from serious infection. And it makes you kind of look at painkillers in a different light, also because you realize well, painkillers are essentially undermining an adaptation that's there to help you and that's why athletes, a lot of athlete bodies, tend to break down when they get older. They should be the bodies that aren't breaking down when they're older. They're the ones that are the most physically fit, right, but a lot of times it's simply because they weren't allowing their body to heal appropriately because of the overuse of painkillers. So again, you could think of that as again a mismatch as well.

Speaker 1: 9:20

So we can think of also explaining why we crave certain foods. Why do we crave calorie dense foods like a steak or a burger, or chicken nuggets or something, or fries compared to a salad? It's not saying that those are healthier for you than a salad. A salad is extremely healthy. What it is is that there's more calories in those things and, again, in an environment that's limited in access to calories, you want to get the most calories possible because it's unlikely that you're going to suffer a problem from having too many calories. So individuals that can acquire meat are going to live, are going to more likely to survive themselves, obviously, and they can raise simply more offspring if they have that craving right compared to something like craving vegetables. So the idea here is that the environment that shaped our bodies again is dramatically different than the environment that we currently live in, which leads to, again, mismatches.

Speaker 1: 10:15

We have to think that we're again adapted to avoid negative energy balances as opposed to avoiding surpluses. We have plenty of adaptations for deficits, correct, right. If a human female, if her body fat drops below a certain percentage, the body simply pauses reproduction. It goes. We can't do this right now. We might have enough fat to maintain you, but we don't have enough fat to maintain you and potentially a pregnancy. So, again, an adaptation to try to minimize the deficit. If you have too much energy, if you have obesity, too much energy, you don't have adaptations in the other direction. The system just breaks in.

Speaker 1: 10:55

With type 2 diabetes, again, we're adapted to avoid the deficits because having a surplus, the negatives of the surplus, so we're simply non-existent. It even goes beyond that. If you were pregnant and starved, then you actually send information down to the developing embryo that this is an environment you're about to be born into that has very, very, very restricted calories. So the baby actually develops smaller organs and a slower metabolism, which makes them more prone to obesity, even if they're given the same diet. So you could see these two mice one quite larger than the other one they were brought up on the same diet, except for the one that was born from a starved mother is actually again more prone to obesity because it's adapted. It's better suited for an environment of low calories. So it's completely maladaptive for an environment with a surplus of calories. And that's why we look at things like people say well, the fat gene. Or oh, there's this gene that makes you more likely to get type 2 diabetes. Oh, it's a bad gene. Those are fantastic genes. They're just not really good in this environment. But those genes allow you to survive off fewer calories than individuals that have the alternate genotypes. So again, a great adaptation in an environment of low calories, but an absolutely devastating trait to have in this modern environment where there's a surplus of calories. So again, we have to think of this mismatch.

Speaker 1: 12:20

Your body's not aware that there's extra calories because it's always thinking that starving is around the corner. That's why it's extremely difficult as I'm sure most of the people listening to this know. It's extremely difficult to add muscle. I mean a lot of the effort with ISSN and people that research in the ISSN are. How do we get the body to do what it doesn't want to do and that is pack on muscle because your body does not want to do it? Because muscle costs calories. It doesn't seem like it costs a lot. About a pound of muscle might cost you six calories per pound a day. Okay, start adding up how many pounds of muscle you have on there and how much you could maybe do away with right. And then you think, conversely, a pound of fat is energy. A pound of fat is 3,500 calories that you're bringing to the table. So that's why your body will gladly put on fat but does not want to put on muscle.

Speaker 1: 13:15

In order to put on muscle, you have to consume a tremendous amount of calories and you have to exert yourself physically a tremendous amount in order to convince your body that it needs the muscle and then convince it that it can afford the muscle. And even if you keep consuming a tremendous amount of calories but you don't work out anymore, your body will still lose the muscle. Your body is not breaking down its muscle when it's starving for energy. It's breaking down the muscle to save energy. So, again, even if you are still on a calorie, a laden diet, a calorie surplus diet, you will still work to lose muscle because your body does not want to. It wants to avoid again a negative deficit as much as possible. Again, you have to think of why we're naturally lazy, why we want to use this elevator instead of the stairs, because if you are motivated to exercise, that's a good way to again run into a low calorie deficit. So we're not motivated to exercise, we're motivated to get the outcome of what usually requires physical activity. So one way of thinking about it is our motivation systems are not to exercise, they're to maximize calorie intake and to avoid calorie deficits.

Speaker 1: 14:26

So get as much energy-rich foods as you possibly can and avoid overexertion and again burning unnecessary calories. So you can think of this like a big old steak here. Right? You want that because it's critical for your survival. It enhances your reproductive success. You're more likely to die from not having enough of it than having too much of it ancestrally. And it's really really, really, really difficult to attain meat because you have to get meat from an animal that usually doesn't want to give it up. So you want the steak. You don't want that. You don't want to deal with the animal, but you crave the meat and you're so starving that you're willing to deal with the animal. So you don't want to exercise, you're willing to deal with the exercise to get the food.

Speaker 1: 15:14

So if you can not do the physical part and get the food, then by all means you want the honey, you don't want the bees, so, but you want the honey and you want the fat and you want the meat so much that you're willing to attempt risky and energetic tasks to acquire it. So it's not the task itself that you want to do, you want to get the outcome of the task. So again, you could think of the classic saw movie. Right, he doesn't want to saw his leg off, he wants to get out of the dungeon. So if you give him a key, he'll gladly just get himself out of there. He's not gonna just turn around later and then put the effort in to cut his leg off Again.

Speaker 1: 15:53

The more dangerous the task, the more risky the task, the more motivation you need to then endure it. So you want fat, you want meat, you want sweets so badly, because it often takes a tremendous amount of work to get. So that's why, if exercising itself felt good, we'd all be dead because we'd be trying to exercise just for the sake of exercising, as opposed to we want the food and we're willing to endure the physical exertion that is required in it. So a helpful comparison with sex you're motivated to do the task itself. The baby comes after right. So that's why humans want to prevent the outcome from happening not getting the baby so they can maximize indulging in the task.

Speaker 1: 16:37

It's basically the opposite.

Speaker 1: 16:39

When it comes to our cravings of meats, fats and sweets, you want the outcome of those things so badly, you're willing to deal with the task and that's why we put our effort into minimizing the effort required to get these calories, to get these calorie-rich foods, and that's why somehow you can get meat and more calories cheaper than you can get a salad, because we want it so badly that we'll bend industry to our will so that they can actually somehow produce meat cheaper than the vegetables that that meat was eating to make it.

Speaker 1: 17:14

So ultimately, again you could see how our cravings are not again to do the exercise we normally had to. We normally had to at cravings so strongly to endure again the activity to acquire it. So I guess a long story short to wrap up the whole talk. Really the best way of thinking about it is when calories and elevators are everywhere, then why would you go to the gym to stall your foot off? So I like to thank ISSN and Jose for the lovely conversations we typically have on this topic and for inviting me to give this little brief seminar.