Thursday, April 28, 2005

The Bulging Waisteline: Why do people overeat?

I look around in the casino, in supermarkets and on the street and I see people who are of average weight, then there are some who are chubby ("overweight") and then there are those who are massive ("obese") and I immediately ask myself: how do these people managepile on that much weight?

While I do agree that there is some genetic factor in obesity, the fact of the matter is that more weight requires more food and we can therefore deduce logically that these people eat more --much more-- than me. And so it's not just an errant gene that influences the person to overeat; rather the person becomes "addicted" to the food by virtue of his or her excessive body mass. Once a person becomes overweight, what is considered overeating to average people becomes regular eating to the obese. But what exactly pulls the trigger?

To answer this, we shall examine animal weight patterns. It is remarkable that we rarely if ever see an obese lion, an overweight cat or a chubby bumble bee. I am surprised that this observation is not more popular; I don't think I have ever read it anywhere but it's a fact nonetheless. And so we therefore see that overeating is somehow associated with some peculiar human characteristic. There is some progressive urge in humans to eat excessively, which -if misapplied- is detrimental rather than beneficial. From what I have observed, the following are advantages of excessive weight:

1. More fats means that the organism has a bigger reserve from which to draw food in a time of need. A bigger and/or fatter organism should in theory be able to withstand a longer fast or a prolonged period of survival on little food.

2. Bigger means stronger. When it comes down to a fight over scarce food resources, the bigger and thus stronger species or the bigger organism within a species will prevail.

3. Bigger means a more stable and resistant life. If a big life is to be destroyed (completely), the individual's constituent parts must be broken apart first. This is how the original life-supporting compound molecules formed such as water (OH2), ammonia (NH3) and methane (CH4) and later the macromolecules of protein, carbohydrates, lipids and nucleic acids which are the direct forefathers of all life on earth.

4. Even though a bigger organism needs more food to survive, it is easier for it to obtain the necessary food than it is for smaller organisms because it can easilly feed off the little ones as well as off the food available to the little ones. This is true because life in the universe is hierarchical, like a pyramid. The ones at the very bottom of the pyramid, such as autotrophs have no "prepackaged" food. They must synthesize their own food off the sun and that is hard work. They cannot "afford" to grow big because they simply are not capable of feeding such a big organism off the sun or thermal vents in the ocean. Species who are higher up in the ecosystem are more sophisticated and have developed mechanisms that allow them to utilize ("digest") prepackacged food not only in the form of plants but also in the form of lower-level species. Essentially, any species that is below its level in the ecosystem, is up for grabs and this presents an overhwelming abundance of food to the high-level species when compared to the food available to lower level species.

However, the additional requirements demanded by bigger species is a serious liability as well. We should not forget what happened to the Dinsoaurs 65 million years ago. Humans now rule Earth; there are 6 billion humans on Earth but there are only perhaps about 20,000 each among species of similar size to humans such as tigers, bears, lions and dogs. Up until 65 million years ago the Dinsoaurs ruled Earth; they were the biggest, the strongest the most numerous and they populated the entire globe. Our ancestors, the little mammals, were puny and up to the mercy of the Dinsoaurs at that time. But it all came to a decisive end when an asteroid from outer space bombarded our planet and obstructed the sun. The big Dinsoaurs required too much food and were unable to survive in a planet with so little sun and so they all eventually perished. The small mammals were mure adaptivebecause they did not require that much food.

And so, we humans who are the most sophisticated descendants of those early mammals from 65 million years ago, have learned that too big could be more of a liability than an asset. And that is why in the course of millions of evolutionary years we chose not to grow our bodies too big. The brain is the organ that did grow the most relative to its size 65 million years ago because we utilize intelligence (which is generated by the brain) and social collaboration to facilitate survival. We deliberately chose NOT to grow the rest of our bodies and so you see that the elephant, the giraffe, the horse and the camal are all bigger than humans but they are obviously inferior and weaker than us when it comes to getting our way through. We are more adaptive to nature and therefore more prone to survive.

People who overeat are essentially making the same mistake that the dinosaurs made 65 million years ago. The urge to overeat is not fundamentally differnet from the urge the dinosaurs had to grow bigger and bigger and bigger. They knew that bigger means stronger, but what they didn't anticipate is the downside to a massive body:

1. a massive body requires more food. In times when there is a super-long period of scarce food sources, the smaller organism can get away with it more easilly than the big one.

2. a bigger organism spends more time consuming food and is thus wasting time that could be spent on more valuable pursuits. Even if the organism develops a bigger esophagus, it still takes more time and effort for the bigger organism to engage in the act of "eating" than it does for the smaller organism.