There is a strong association between health status and phenotypic expression. This is something we instinctively know, but it’s largely overlooked within conventional medical circles nonetheless, which is unfortunate, seeing as one can tell a lot about a person’s health and medical situation by examining his or her physical appearance.
Whereas characteristics such as white teeth, acne-free skin, thick, beautiful hair, and strong glutes and upper back muscles are all symbolic of good health, characteristics such as high body fat levels, poor posture, and “sunken” facial expressions are indicative of suboptimal health. By tracing these physical characteristics back to the stimuli that produced them, one can alter the health status and appearance of the individual(s) in question.
The hunter-gatherer baseline
The hunter-gatherer lifestyle – the original/default lifestyle of hominins – produces a characteristic set of phenotypic traits. Foragers are lean and moderately muscular (1, 2, 3). They tend to have well-developed jaws and dental arches and good posture (1, 3, 4). Furthermore, they rarely or never get acne and have good eyesight (1). These traits form the evolutionary phenotypic norm, in a narrow sense, for our species Homo sapiens sapiens. Deviations from this hunter-gatherer baseline typically reflect evolutionary mismatches.
Perhaps needless to say, modern, industrialized environments produce human phenotypes that differ markedly from those that are produced by natural environments that resemble the milieus in which our preagricultural ancestors lived. When exposed to modern environments in which highly processed foods, transportation vehicles, and pharmaceutical drugs are ubiquitous, the human genome expresses a suboptimal phenotype.
Industrialized humans tend to be overweight and carry low levels of muscle mass. Moreover, in most developed nations, as well as in many developing countries, acne vulgaris and other similar skin disorders are extremely common, a lot of people have bad posture, and if you go out on the street and look around, you’ll see that a lot of people look drained of energy and carry themselves in a way that is symbolic of chronic fatigue and/or depression.
This is not surprising, seeing as we – modern humans – are exposed to a wide range of environmental forces that the human body has little to no evolutionary experience with.
Building healthy humans via reverse engineering
By paying attention to the physical characteristics of humans who are exposed to different types of environments, as well as by looking into what types of environmental exposures that are required to produce different phenotypic traits, one can create a blueprint for building healthy, as well as good-looking, humans. It’s important to recognize that there’s a lot of overlap between the physical traits that we generally consider to be attractive and the traits that are strongly associated with health status. This isn’t surprising, seeing as we’re evolutionary programmed to seek out healthy mates, in part because healthy mates are more likely to produce healthy offspring that manage to survive and reproduce. For example, strength and muscularity are typically considered attractive features. These features are also, to an extent, reflective of good health and physical robustness.
A person who is fairly knowledgeable about how the human body functions and how our physical appearance is affected by outside forces can, via “reverse engineering”, “build” humans with different phenotypic traits. For example, acne vulgaris, a common disease of civilization, is largely absent among humans who live in natural environments. This condition is largely caused by hyperinsulinemia, inflammation and dysbiosis. If one exposes a child to a proinflammatory diet, antibiotics, and/or other environmental agents that are known to cause hormonal issues, inflammation, and dysbiosis, acne vulgaris is, with a high degree of certainty, going to rear its ugly heads. Conversely, if the child is not exposed to these detrimental forces, he’ll be at a lower risk of developing skin lesions as he gets older.
Similar types of principles apply to other health conditions. The key thing to acknowledge is that our phenotypic characteristics partly reflect the environmental stimuli our bodies have been exposed to throughout our lives. Obviously, we can’t change our eye color by changing what we eat and how we live our lives; however, we can change our body fat levels, the texture of our hair, how much muscle we carry, the moisture levels of our skin, and so forth.
One of the first things I tend to do when I start working with a new client is to quickly examine his or her physical appearance (e.g., posture, body fat levels). This way I get an immediate impression of the client’s health and well-being. This type of examination obviously doesn’t tell me everything I need to know about the client’s body and medical status; however, does it equip me with some basic information about the client that I can use as the basis for our work together.
How you can use your physical appearance to improve your health

Many physical characteristics that we humans generally perceive as unattractive and pernicious, such as acne-laden skin, clearly visible belly fat, and hunched shoulders all reflect suboptimal health. Acne, as previously mentioned, signals that the body is chronically inflamed and harbors a dysbiotic microbiota. Excessive fat mass goes hand in hand with chronic inflammation, in part because fat tissue, when it’s overwhelmed with energy, initiates an inflammatory cascade. Overweight is also strongly associated with insulin and leptin resistance. Finally, poor posture is typically caused by muscular imbalances and weaknesses, which tend to undermine health.
Inflammation is a common denominator linking many deleterious physical states and characteristics (5, 6, 7). If you are overweight, suffer from a skin disorder like acne or eczema, feel drained of energy, and/or otherwise don’t feel or look as well as you’d liked, then chances are your body is chronically inflamed and you could benefit from changing your diet and taking steps to improve your microbiota and immunity. By keeping tabs on how your physical appearance changes as you alter the types of stimuli that your body is exposed to, you can determine whether what you’re doing is working or not.
It’s important to point out that simply assessing a single variable (e.g., body fat levels) is not sufficient to make any solid inferences about a person’s health status. A lean person or a person with clear skin isn’t necessarily a healthy person. Genetics do matter. Leanness and/or lesion-free skin are both suggestive of good health; however, it’s the composite of physical characteristics that matter the most. Many characteristics that are perceived as undesirable commonly appear together, seeing as they have the same or similar origins.
Great article Eirik. You’re on Dan John’s radar now. If you don’t know who that is google him.