Why you get fat and you can't sleep.

Evolutionary mismatch theory

Unfortunately, or maybe fortunately, our modern environment has changed so much in the recent 1-2 thousand years that it would be unrecognizable to our ancestors. The issue with this rapid change is theg many of humans' evolutionary adaptations that developed prior to this radical shift in the modern environment still are in the human DNA.

Many refer to this phenomenon as an evolutionary mismatch, which is simply when an evolutionary adaptive trait is unfavorable in the modern environment. The prevalence of these evolutionary mismatches has increased drastically throughout the past few hundred years, due to the massive expansion of technology, industry, and all the novel inventions of the western world.

However, because this has occurred so quickly, and so recently, humans still express a very similar set of genetics as our ancestors, who lived as hunting and gathering nomads. These genetics adapted to this environment over the course of roughly 190,000 years, and it is only the last few hundred that humans have been living in the modern environment.

Thus, if one truly wants to understand why human genetics have evolved in such a way that we are genetically programmed to promote specific behaviors that appear to be disadvantageous In the 21st century, we may need to look to our ancestors we simply can't look at many of our genetics as adaptations to the modern environment, but adaptations to our past circumstances.

An Evolutionary explanations of cravings

For example, why would humans have an innate craving for foods with the highest calories? In the 21st century calorically dense foods, and our immense craving for them, seem to be contributing substantially to our current epidemic of excess body fat accumulation.

However, if we approach interpreting this innate drive in the context of our ancestors, the environment they found themselves in was much more scarce. Additionally, they often endured prolonged periods of the year where they may NOT have had an abundance of calorically dense foods, and only found these foods in a certain portion of the year. Therefore, it makes sense that we have developed and innate drive to over consume on calorically dense foods when they are available.

We also developed adaptations that decrease our metabolic rate when we are not eating sufficient calories. This is why many individuals experience a decrease in energy expenditure as the phase of weight loss.

Another set of traits we developed allow us to store as much weight as possible immediately after a period of deprivation. This is why many individuals find unexpected rates of weight gain after a prolonged period of weight loss.

These adaptations, along with a propensity to seek calorically dense foods, developed because the most successful humans stored large amounts of weight when food was available, and were efficient at conserving energy when food was scarce.

Unfortunately, our ancestors did not value looking photoshoot ready all year round, therefore they did not make any genetic adaptations that were favorable for looking like a movie star.

Rather, many of our adaptations have been made such that we can survive in an environment that was far more dangerous and scarce than the westernized culture.

Sleep through an ancestral view

Another extremely poignant example is sleep. The things that allow humans to get the deepest sleep are things that suggest a sense of safety in the environment. Two tactics that have been found to be beneficial for sleep include a very quiet room, and a very dark room.

When the environment is very quiet, it suggests we have found a location that does not have potential predators in it. Additionally, small noises throughout the night decrease our levels of deep sleep. Simply, when there is noise in the environment, we have genetic adaptations that do not allow us to get into the deepest, most VULNERABLE stages of sleep. Instead, we stay in light sleep so that we can much more easily wake up and react to a danger in the environment.

In reference to darkness, the darker the environment, the less visible one would be to most predators. Moreover, light in the environment suggested it was still daytime, and many predators may still be looking for dinner. Consequently, anything that would suggest to the human mind that daytime is still among Us, such as light in our environment, keeps the brain active so we do not go to sleep during the day.

I find the key takeaway to these observations to be the idea that anything that seems to promote safety also seems to promote better, deeper, more restful sleep. These things include:

• Blocking blue light, and increasing the red light in the environment, such that the mind believes night time is quickly approaching.

• Lowering the temperature of the environment, as another physiological indicator of night time approaching.

• Using things to block out noise, such as earplugs or a white noise generator.

• Avoiding arousing and stimulating content, like the news, social media, and scary films prior to bedtime, such that the body is not placed into a state of arousal and rumination due to the content we are engaging with.

• Possibly, the use of a weighted blanket, I'm simply something to grasp onto which makes us feel secure in our environment.

• Avoiding caffeine late in the day, because it will block adenosine. Adenosine is a chemical that accumulates throughout the day, and be washed out during the night. If it does not accumulate, the brain is less capable of discerning the time of day, and remains alert and aroused. Adenosine is also referred to as the "sleepiness chemical."