There are many reasons for this in terms of today’s advertising and marketing, nutritional  biochemistry and social sciences. 

More Candy 

First of all, what comes to mind when fast food is mentioned is not only foods such as  hamburgers and fries, but also the carbonated drinks that accompany them. Most of these  sodas contain up to 10 times more sugar than the sugar in fast food. Excess sugar causes  us to eat more and become addicted to sugar in the long run. 

More Dopamine 

An extension of sugar consumption is the reward-punishment mechanism. Reward systems  in our brains have evolved to reward behaviors that encourage us to survive. While meeting  our basic needs such as eating, this reward system comes into play and a chemical  substance called dopamine is released.  

We also perceive this oscillation as “pleasure”; that is, what we call “pleasure” is actually the  sensations created in our brain by this hormone secreted from our brain. We prefer these  ‘pleasure centers’ that we know will make us happy, rather than eating in an unknown place.  This situation causes us to increase the consumption of fast food wherever we are in the  world.

More Calories 

Calories also reinforce the reward mechanism! So the reason we want to choose fast food is  not a cheese or sauce we like, but calories. High-calorie foods directly affect the brain reward  system. In an experiment by scientists with mice lacking sugar taste receptors, the mice were  

provided with regular water and sugar water. Although the mice preferred normal water at  first, after a while they started to turn to sugar water. Our brain can recognize and prefer a  calorie diet even if it does not perceive the taste. 

More Hormones 

Dopamine is not the only hormone that causes us to prefer fast food. The GIP hormone,  which controls insulin and energy expenditure, and the leptin hormone, which creates a  feeling of satiety and informs us to stop eating, also play a direct role in this process.  

When fatty foods are consumed, the level of GIP in the body increases and goes to the  hypothalamus. And there it delays the feeling of satiety by preventing leptin from working.  This causes us to eat more than we need. Fast food aims to manipulate this process thanks  to the excessive fatty foods it contains and causes us to consume even more fast food. 

More Salt 

Monosodium Glutamate (MSG) is a derivative of glutamic acid and passes as a salt in  acidity. MSG stimulates taste receptors, allowing you to perceive food more deliciously and  to accept it easily. The use of monosodium glutamate is a controversial issue in terms of  ethics and food science. 

Although some studies say that it can be harmful if consumed in excess, many countries’  health departments have approved the use of MSG and FDA categorize it as “generally  safe”. 

Lower Cost 

The fact that fast food can be much cheaper than many alternatives can also be seen as a  factor affecting people’s preference. However, this is an illusion. Because it is fast and  accessible, it is consumed more than needed, and the treatment costs of the diseases it  causes will become more expensive in the future. 

Therefore, a certain diet may seem a little cheaper, a little easier, a little more accessible  than another in the short term; however, if it causes chronic diseases that are difficult to treat  in the long term, that “cheap and quick” diet may be seen to be much more expensive and  challenging.