When we're feeling down, many of us have a natural instinct to reach for a pint of ice cream and watch a movie. Or when we had a bad day, we may shoe down a whole pizza. Why does food comfort us so much?

There is scientific reasoning behind this. According to researchers from the University of California, the fatty acids from unhealthy foods increase the levels of serotonin, the hormone responsible for making us happy.

Also, there are two mood-related neurotransmitters. One excites our body and mind and the other calms them down. Either of them can lead to unhappiness when there is an excess of one. A balance can ensure one's happiness. The chemicals responsible for the neurotransmitters come from compounds in foods. Therefore, it is essential to eat a proper amount and a balance of foods. For example, bananas and turkeys increase the levels of serotonin, which is an inhibitory or calming neurotransmitter.

Psychologically, certain foods remind us of our social relationships, making us feel less alone. For example, when I was a camp this summer at Stanford away from my parents, the cafeteria served pesto pasta one day. It was a food that my mom often cooks me for lunch. Automatically, I felt relieved and happy eating the food.

Food can also remind us of certain events. If you ate vanilla cupcakes at your graduation ceremony, you may be comforted by eating vanilla cupcakes when you are upset. On the contrary, food can also remind us of negative events. If you ate sushi and threw up, you may not like eating sushi because it reminds you of getting sick.

Make sure to know what type of food comforts you so that next time you feel upset or stressed, you can rely on your comfort food to cheer you up.