The Chemistry of Eating


    • Eating is a process used to get the required energy that a person needs to live into the body. It would not be possible to live without eating, as the body needs the energy that comes from food to stay alive. The process of eating uses the digestive system, made up of the mouth, the throat, and the stomach as its main parts. Eating also creates many careers and is at many times used for enjoyment.
    • I chose the chemistry of eating because it is something I do often, and because I like to eat. I eat 3 meals a day, with tons of snacks in between. I thought it would be cool to find out about how eating works and why it affects everyone so much.
  • Much of life is centered around meal time and food. Food brings people together, and sometimes lunchtime is the only time I get to socialize with some of my friends. I enjoy eating, and if I stopped I would die, so I would say that it is a pretty big part of my life.

Composition of ...

    • Digestive System
      • Saliva
      • Teeth = CaPO4
      • Stomach Acid = HCl
      • Esophagus
      • Intestines
    • Food
    • Brain
      • Glucagon = C29H41N9O 10
      • Epinephrine = C9H13NO3
      • Ghrelin = C147H245N45O42

Main Chemicals, Compounds, Components

Digestive System - (Saliva, Teeth, Stomach Acid)

The most important part of eating is the digestive system. Starting out with the mechanical process of chewing and the chemical process of salivation, food begins to be broken down. It then moves down the esophagus into the stomach, where it is further broken down in the acid of the stomach. Everything is moved to the intestines, where the nutrients from the food are absorbed through the intestinal walls into the bloodstream and are used to keep your body running. Waste is also removed from the body using the digestive system. Four types of food molecules are broken down and absorbed. Proteins are broken down into amino acids and absorbed individually. Fats are broken down into fatty acids and glycerol. Carbohydrates are broken into starch, fiber, and sugars. Vitamins are classified as A, B, C, D, E, F, and K. They are grouped by the fluid that they dissolve in.

The Brain - (Glucagon, Epinephrine, Ghrelin)

In the brain there are chemicals called neurotransmitters. These chemicals affect mood and feelings, and are created in the body. Glucagon, epinephrine, and ghrelin are the chemicals tied to hunger and satiety (the sensation of being full). They are released in the brain when your body needs food and while you are eating. Triggers for the release of these chemicals include lowering blood sugar levels, dropping blood levels of amino acids, and less fatty acids in the body.

Chemistry's Role

Chemistry, not only keeping you alive every second of every day, also is the reason you can eat. With chemistry, the body and everything in it is created naturally. While food is man-prepared, it also comes naturally in nature from the power of the sun. All processes in the body, including the digestive system and the brain, are naturally occurring and even man cannot tamper with them. Eating is made possible through the mechanical and chemical processes found in chemistry.

Background Research

Hunger, eating, and the pursuit of food have driven human evolution from the beginning of time. Eating is required for humans, as there is no other way to obtain the energy necessary to live any other way naturally. There are essentially two types of foods that are able to be eaten - meats and plants. This creates different eating lifestyles for humans. Across the world, there are many different eating practices, from what people eat and what people use to eat, to how people eat.


signals of hunger and satiety

chemicals in the brain released before, during, after eating

eating practices of humans

how chemicals in the brain affect moods and appetite

how nutrients in food affect moods and appetite

What is the digestive system

How it works

What chemicals break down food

Nerve regulators

why do we eat?

neurotransmitters in the brain

why we do what we do

what is hunger

why hunger drives humans to eat and how

what do humans eat

taste perception

how chemicals in the brain work

chemistry of glucagon

chemistry of epinephrine

About the Author

Dave Miller is a junior at Billings Senior High. He runs cross country in the fall, rock climbs in the winter, and pole vaults in the spring. Along with all of his physical activity he eats a lot of food to keep in shape. Dave plans to go to college for an engineering or medical degree, although he doesn’t know where yet. He has two brothers and a black lab puppy.