WHY DO WE EAT TOO MUCH?

“Persons who are naturally very fat are apt to die earlier than those who are slender.”  -Francis Adams

As assumed, the amount of food we consume isn’t always under our willful control. After all, we are the children of our ancient “survival of the fittest hunter- gatherer” ancestors. Only those ancestors who were able to eat too much and get fat, during the feast season, survived the upcoming famine season and became  ”the survival of the fittest.” Those ancestors passed their overeating genes to us. So then eating too much is an evolutionary genetic character we acquired from our ancient ancestors.

In modern times, there is no famine anymore. Plenty of good tasting, calorie dense foods and difficult to resist junk foods are available to us 24/7. This means we continuously live in a ”feast season.” Since it is in our nature to eat more than we need, many of us get fat. I believe this is one of the main reasons why the obesity epidemic is engulfing the entire world.

Let’s now review the physiology of hunger and satiety feelings so that we can understand overeating  and to better deal with it. Feelings of hunger and satiety originate in the specialized regions of ourbrain. But our stomach and intestines are the organs that eat and accommodate the amount of food we consume and digest it. Therefore, there has to be close communication and cooperation between ourstomach, gastrointestinal tract and our brain so that our brain could create, in a timely fashion, the necessary hunger and satiety feelings.

When our stomach and guts are empty of food, the special cells in our stomach produce a hungerhormone called Ghrelinto inform the brain that it is time to create a hunger feeling and to eat. As we eat and our stomach becomes full, even though our stomach has an ability to dilate and accommodate more food, the level of ghrelin hormone drops. At the same time, a satiety hormone called Leptinisproduced by the fat cellto notify the brain to create the feeling of satiety. It is interesting that our fat cellsalso communicate with our brain. Because our brain has to know how much fat reserves (depo calories) exist to survive a possible upcoming famine.

So it appears that this Ghrelin /Leptin hormonal system controls when and how much we eat. But it does not appear to be as simple as that. For example, the Leptin hormone, when given to lab animals to suppress their appetite, makes them lose weight. But this unfortunately does not work the same way for humans.

The mechanism of appetite and eating behaviors are much more complicated than two simple hormones. Genetics, epigenetics, additional hormones, personal habits all play a role on over eating.

Researchers found another gene that regulates satisfaction and elation after eating a delicious meal by producing excess dopamine, which stimulate brain’s reward centers. Some people have to eat more to have the same feelings.

In morbid obesity cases, there is genetic mutations in genes that control appetite hormone production and/or their receptors functions, causing overeating and morbid obesity.

So, it appears that for some people, their appetite can’t be controlled by willpower alone, it is beyond their control. Over eating is in their genes.