Why Are We Overweight? Part 6
As man has evolved, the way we procure food has changed as has the very act of eating. The take-home message from earlier installments is that these changes are a significant reason why there is an overweight epidemic sweeping the world. Simply stated, differences in these fundamental determinants of energy balance have rendered our inherent biological system that regulates appetite and physical activity ineffective for maintaining appropriate body fat levels. Consequently, our behaviors in this regard do not match those that are required to optimize health.
The innate cycle that ensures equilibrium with respect to energy balance would start with the ledger in the red as should be the case upon awakening. The natural consequence would be a feeling of hunger and a drive for physical activity that is necessary to find food. Once food is found, the desire to eat would be maintained until enough energy had been ingested and once equilibrium was achieved, the motivation for both eating and physical activity would be suppressed. Sleep would then complete the cycle. The important thing to recognize is that at no time is a positive energy balance consistently encountered within this schema. The contrast brought on by the present environment is that food palatability plays an important role as do non-instinctual aspects of eating that are based upon social and cultural influences. The end result is that we often ingest more energy than we require, which places us in a positive energy balance that motivates inactivity and perpetuates a vicious cycle.
In accordance with the theory of natural selection, it is intuitive that evolutionary change is progressive; therefore, the solution to this problem is not that we should revert back to spending much of our day foraging and gathering unpalatable food that will be eaten for necessity and not pleasure. After all, if everyone had to donate countless hours to this pursuit, there would be little time left to send men to the moon or cure cancer. But I believe it is also true that for every evolutionary step we take forward, there is a small price to be paid and if homo sapien really is what the name implies (wise man), he must take this into account. Establishing an appropriate energy balance in the 21st Century provides a great example.
There is no doubt that eating can be a very pleasurable experience given the current options available. Therefore, (at least this) wise man is not going to restrict his diet to bland options that get the job done, but little more. And while we’re at it, I’m also not going to deny myself the pleasure of eating in an environment that I find enjoyable; for example, while reading, watching TV or socializing with family and friends. But I am going to be aware that these influences will skew my perception of how much I should eat, so instead of going by instincts, I’ll have to make conscious decisions. In other words, I’ll have to use my evolved brain in place of my innate instincts.
In this day and age, every person must know the energy content of the foods they eat because even though it might seem time consuming to look up caloric values on the Internet, calculate appropriate portion sizes in a spreadsheet and dole out servings with the use of a digital scale, these are modern-day requirements that pay the price associated with progression. And in addition to determining how much energy to ingest by calculated decision instead of intuitive reflex, wise man must also understand energy expenditure and how to ensure that daily outlay matches (and if excess body fat has already been accumulated, exceeds) that which is taken in. Much like eating with no regard for energy intake (even if one sets out to eat in a healthy manner) is not the appropriate strategy for modern wise man, simply exercising without consideration of the energetic requirements of the activities being performed is also an approach that has been rendered obsolete. Case in point: I witness many people at the gym walking slowly on the treadmill or pedalling the bike against light resistance such that energy use per unit time is relatively low. Could they work at a more vigorous pace? Probably, but they appear content to simply maintain status quo. Now, if this expenditure jives with the energy they are ingesting to create the appropriate energy balance, this is no problem. But in many cases, fat stores and, more importantly, changes in such over time suggest this is not the case. And it is also important to factor in the energy the person would be using if they had decided to skip the trip to gym that day altogether. For example, even if one was to approach exercise in a calculated manner and plan and track precisely how many calories they were expending, it’s important to remember the value would include the basal energetic requirement, which is present even during sleep. And as for the additional cost that is created by the exercise itself, with what I often see, I can’t help but wonder (at least from an energy balance perspective) whether many of these gym goers would actually be no worse off if they were simply performing equally benign activities of daily living.
This article was originally published in New Living Magazine, which can be accessed on-line at www.newliving.com.
