Cellular Biology

The Science behind Weight Gain

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"The Science behind Weight Gain"
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Though simple to understand, the body mass and its fat are a bit more complicated than that. First and foremost, one should know that fat is a good thing. It is necessary for insulation in the hot as well as the cold weather. It is a soft cushion protecting muscles and other vital parts of the body. Finally, it is what protects the womb in times of pregnancy.

Overweight people have been around long before Twinkies and Dunkin Donuts luring the unsuspecting to sinful calorie and unsaturated fat intake. The difference is that they were fewer in number, but their type of fat also differed.  There is an entire science behind this subject of weight gain and loss, especially since in modern-day society it dictates the quality of life a person leads.

*Fat cells

Fat cells (or the adipose tissue) are located in specific areas of the body. For the man, it is usually the chest, abdomen and buttocks while for the woman it is the breasts, hips, waist and buttocks. Women have fat cells in more areas because they are child bearers, thus the area of the womb needs protecting.

Interestingly enough, the number of fat cells grows until puberty. After that they grow in size and not number, unless they become full with fat; then they increase again in number to accommodate the extra fat intake. The number of fat cells varies between 10 and 30 billion, depending on body frame.

They are a vital part of sustaining the life process! Their number and shape are directly connected to the form of one’s body. Thus while the number of cells is fixed, when eating less, less fat is consumed and the cells do not grow in size. When coupled with exercise, the fat consumed is turned into energy resulting in smaller cells and an individual full of life. How then does food intake become fat and get stored in the fat cells?

*Fat storage

Once the food is digested and decomposed into minute particles, it is sent into the small and then the large intestine before the excess intake is removed as waste. The fat consumed, however, cannot be broken down as easily as protein or carbohydrates; fat is digested last. This is due to the fact that this substance contains the biggest molecules. So, while fat sits in the stomach, digestive juices lubricate it, unable to dissolve it into smaller pieces. When fat is sent to the large intestine, bile acids from the liver, pancreatic fluids and intestinal enzymes together break the fat molecules apart.

At this point the broken-down saturated fat molecules are carried in the form of low-density lipoprotein cholesterol to cells for storage instead of eliminating it as waste. However, the unsaturated fats are transported by healthier cholesterol, high-density lipoprotein (if accompanied by a fiber-rich diet, it can assist in quicker proper bowel movement) and eliminated as waste.

The above process is how the cells grow bigger in size. Lipases are insulin-triggered enzymes which are activated and absorb fat, storing it in the cells. The more insulin there is, the more lipases are activated. Consequently, this results in the expansion of cells.

*Why fat is necessary

Analytically, fat is the backup system for energy when blood sugar supplies are diminished. Moreover, it insulates nerve fibers, which in turn help send out nerve impulses. Every cell membrane in the body uses fat because it helps carry nutrients and metabolites (these are organic compounds necessary for various processes, including metabolism) across cell membranes. Finally, the body needs fat as a building block for many reasons, ranging from producing hormones to immune function.

*Why does one eat?

As everyone will most likely know, food is used by the body as building material and stored as a source of fuel. The body is designed to function with automatic systems of "stop" and "go."  "Go" find food when hungry and "stop" when full. Why then is it that so many people overeat?

In this modern day and age, people have learnt to use or manipulate food. Many use it to subdue boredom, appease fatigue and make up for lack of love, support or even loneliness. Any overweight person realizes that, but how does one get to that point? The answer lies in a multitude of factors. Firstly, it depends on the individual character of the person. Meaning it is how the individual combats problems from a very young age. According to a 1980s study, it was discovered that many overweight people had been subjected to some form of abuse while growing up. These individuals turned to food to swallow their hurt or despair because they had, or thought they had, no other alternative.

Obesity is a phenomenon of the modern-day consumerist society. Although overweight people did exist in the past, they were the wealthy minority and not the poor majority which is the case today. Certain foods today are a cheap alternative staple and means of pleasure. But that is the emotional side of overeating. What then is the scientific explanation of the process that takes place or perhaps does not take place in the brain so that the individual ceases or continues to eat (even when full)?

Overeating: A chemical process

Many of you may not have heard of leptin, but it is a hormone which circulates in the body. It is made up of 146 amino acids, and it plays a role in several functions in the body, especially body fat regulation (according to the Kenyon College Department of Biology). It is produced mainly by the fat tissue and is necessary for controlling appetite and determining the amount of energy burnt. A deficiency in leptin, therefore, has been cited as a cause for obesity.

This is a complicated hormone not yet fully understood, but in essence it is responsible for suppressing appetite and decreasing food consumption. Additionally, it improves energy consumption in muscles and other tissues and boosts fertility and gonadal development (gonads are a part of the development of the reproductive system and ultimately form the testes and ovaries).

But lack of leptin is not the only responsible factor for overeating. Low levels of serotonin, dopamine and norepinephrine can also add to this phenomenon.  Dr. J Renae Norton reveals that for the different type of eating disorders (five main types: compulsive, impulsive, impulsive-compulsive, anxious and emotional) there are chemicals responsible.

For instance, low serotonin in the brain causes another part called anterior cingulate gyrus to work too hard. This, among other things (depression), promotes obsession over food, especially eating at nighttime. Furthermore, a low dopamine level decreases the function of the part called pre-frontal cortex. A dysfunctional pre-frontal cortex will not allow an individual to rationalize over his actions nor learn from his mistakes. Thus, the person will not be able to control his eating habits. Last but not least, the basal ganglia (a large collection of cells deep in the brain) when overactive can cause anxious overeating. When this condition is at work the individual tends to use food to medicate his symptoms of stress.

For several decades now, overeating has not only become a problem for obese individuals but for their respective countries, as well (increase in health hazards and loss of productive citizens). Thanks to science, the next step for an overweight individual is to find the various roots to the chemical malfunction that may pertain to him and to view more closely the real culprit behind his obesity in order to find his way out of that labyrinth. This writer would like to close with one last note: Where there is a will there is always a way, and may it come better late than never.

More about this author: Litsa Podaras

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