The famous movie star and former wrestler Dwayne ‘The Rock’ Johnson seems like a great, genuine guy. I like him a lot. I don’t agree with everything he says about diet and health though. The Rock is a really hard-working (both in and out of the gym), determined, strong, and muscular guy. I don’t doubt for a second that he knows quite a bit about bodybuilding and how to best go about building strength and muscle. With that said, I think some of his statements regarding diet and fitness miss the mark.
Quite recently I watched a video on YouTube in which a reporter from ABC News interview Dwayne Johnson. In the middle of the interview (1.28 min in), as they are talking about how one should eat to build a lean, fit body, the Rock firmly states that “carbs are your friend”. I largely disagree with this statement. I have nothing against carbohydrates per se; however, I do think Johnson’s statement is overly simplistic, particularly seeing as it didn’t appear to be directed solely towards people who are very physically active, but rather towards the average guy and girl who wants to get fit.
I know Johnson probably didn’t say what he said because he believes it’s safe and healthy to stuff oneself with carbohydrate-rich foods at every meal, but rather because he wanted to make a point. With that said, from what I’ve read about the Rock online, I’ve gathered that he likes carbs. A lot. He undoubtedly inspires a lot of people to lead an active lifestyle and hit the gym on a regular basis; however, I suspect that some of the tips he shares with his fans, in particular those that have to do with carbohydrate intake, may do more harm than good.
Most contemporary humans take in excessive amount of carbohydrate
Dwayne Johnson undoubtedly knows a lot about bodybuilding; however, I’m willing to bet that he doesn’t know much about the evolution of the human diet, the etiology of the diseases of civilization, or the processes that shaped the nutritional requirements of Homo sapiens. The fact is that it’s only very recently, on an evolutionary timescale that it became normal for members of the genus Homo, of which only extant species is Homo sapiens sapiens, to take in very large quantities of starches and sugars on a daily basis (1, 2, 3).
Prior to the time when the Agricultural Revolution started “sweeping” the globe some 10.000 years ago, all humans subsisted on a diet composed of wild plants and animal foods. Back then, pancakes, ice cream, chocolate, and all of the other highly processed, sugary foods that are ubiquitous in modern, westernized environments were obviously nowhere to be found. Moreover, the wild plant foods that were available to Paleolithic humans were smaller and typically contained much less sugar than modern, domesticated fruits and vegetables (1, 4).
Finally, ancient humans rarely ate grains, which contain a lot more carbohydrate by weight than tubers and other vegetables. They may have consumed some honey; however, seeing as honey is only seasonally available in some parts of the world, it probably didn’t make up a major part of the stereotypical Paleolithic diet.
What all of this is to say is that the average preagricultural human took in a lot less starches and simple sugars than the typical modern man. Throughout more than 99% of the evolutionary history of our genus, Homo, a so-called low-carb diet was the normal human diet. This idea is supported by a large body of evidence, including studies that have looked into the nutritional composition of modern hunter-gatherer diets (3, 5). It’s only very recently that it became normal to derive >50% of one’s calories from carbohydrate.
This is very important to acknowledge, because it implies that we are likely inadequately adapted to eat a high-carbohydrate diet, in particular one that contains a lot of grains and/or highly processed foods. One doesn’t have to look far and wide to determine whether this notion is correct or not. All one needs to do is to go on PubMed and do a couple of quick searches. The evidence showing that the carbohydrate-heavy modern diet doesn’t agree with the human biology is overwhelming. The consumption of highly processed, carbohydrate rich foods have been linked with everything from obesity to chronic inflammation to Alzheimer’s disease (6, 7, 8, 9). Moreover, as I’ve pointed out here on the site in the past, multiple lines of evidence shows that it’s unhealthy to eat a lot of grains.
This shouldn’t come as a surprise, seeing as chocolate, ice cream, bread, pasta, and many other modern foods have a nutritional composition that differs markedly from that of the foods that were a part of the diets that supported the evolution of the complex human brain and body for millions of years prior to the Agricultural and Industrial Revolutions. Among other things, the aforementioned modern foods contain very high quantities of sugars and/or starches; hence, they are capable of rapidly raising our blood glucose and insulin levels. This is problematic, seeing as the human metabolic system evolved under low-carbohydrate conditions.
Most people would benefit from replacing some of the starchy and/or sugary foods they are eating with foods that contain protein and/or healthy fats
I would argue that most contemporary humans would benefit from reducing their intake of carbohydrate. Instead of providing our bodies with a constant supply of starch and glucose in the form of pasta, pastries, crackers, and/or bread, we would arguably be much better off if we adhered to a diet that resembles the original human diet. This idea is supported by an ever-growing pile of research data.
Some hard-training athletes who perform a lot of anaerobic exercise, such as bodybuilders, typically need to take in more carbohydrates than sedentary people in order to keep their bodily systems running smoothly. With that said, one should be careful not to go overboard. The average guy who’s trying to get fit doesn’t need to constantly stock up on carbohydrate-rich foods in order to get the energy he needs to perform optimally in the gym. Some fruit and starchy tubers, as well as perhaps some brown rice, usually goes a long way.
Some people report that they “crash” on a low-carbohydrate diet. In my experience, that’s not necessarily because they are taking in insufficient carbohydrates per se, but rather because they have never given their bodies time to adjust to their diet and/or that they are chronically inflamed. A lot of these people could probably get away with eating less carbohydrate if they were patient and perfectly healthy.
The Rock is as far from average as you can get. He exercises a lot; hence, I don’t find it surprising that he feels that he needs to take in a lot of carbohydrate in order to fuel his body. What he doesn’t seem to fully appreciate, though, is that very few people exercise as much as him. In the video mentioned earlier, he doesn’t give the impression that the advice he’s sharing is solely intended for hard-training bodybuilders. Rather, it seems to be directed towards anyone who wants to improve their physique. This is worrying, because in my opinion, most people would benefit from taking in less carbs, not more. Not only that, but I think people would be wise to stay away from the high-volume, high-intensity bodybuilding-type training that goes hand in hand with The Rock’s eating regime. In other words, if the goal is to attain great health, it could be argued that there are no legitimate reasons to eat a diet that’s very high in sugars and starches.
Before we wrap up, I would like to point out (again) that I that I have nothing against either Dwayne ‘The Rock’ Johnson or carbohydrates per se. I like The Rock and have watched many of the films he’s in. As for carbohydrates, one shouldn’t forget that glucose, fructose, and so on are a natural part of the human diet. Moreover, it’s important to remember that different types of carbohydrates are digested and metabolized differently. Whereas starches and sugars are primarily degraded and absorbed in the uppers parts of our digestive systems, fibers pass all the way into our colons, where they are broken down by bacteria.
The point of this article is not to scare you away from all carbohydrate-containing foods, but rather to point out that it’s very abnormal, from an evolutionary perspective, for a human being to eat a diet that contains a lot of pasta, bread, pancakes, and other similar foods. The Rock seems to like those foods a lot. I don’t, in part because the amount of carbohydrate they contains far exceeds that of the foods we are genetically well-adapted to eat.