What Is Food?

Food is any material consumed to supply nutrition to an organism. Food is generally of vegetable, animal or fungi origin, and has all necessary nutrients, including proteins, carbohydrates, vitamins, or even minerals. Plants produce food by means of photosynthesis, while animals eat food either by means of their diet, or through hunting, killing prey, eating other animals, and eating of plant foods. Fungi eat a variety of things, including carbohydrates, sugars, roots, seeds, and bacteria. Organisms use energy derived from the food they consume to grow, multiply, and develop. Humans are an active example of the way food is used, since they consume a food to grow, reproduce, repair organs and body systems, build muscles, maintain mental acuity, create language, and perform other daily activities.

The way our body absorbs food is by the process of digestion; this involves the break down of food into simpler compounds that are more easily absorbed in the blood stream. Some substances are more easily metabolized than others, including protein, fat, carbohydrates, and certain vitamins. The food that is digested will pass through the small intestine, which absorbs it into the bloodstream. The blood stream then sends nutrients to the different cells of the body, where they are used for energy. The food that does not get metabolized will enter the stomach, the esophagus, the small intestine, or other parts of the body where it is not used. Since each of these organs only processes a limited amount of food, the rest is then excreted from the body along with the waste products that are waste products.

A major part of the food that we ingest is protein, which provides the essential amino acids for building and repairing cells. Amino acids are the building blocks of proteins, which are responsible for the development of all the tissues and organs of the human body. Many types of food contain many different types of amino acids, including milk and meat, which usually contain casein and whey proteins. Other foods, such as vegetable and fruit juices, contain mostly lactic acid, which produces carbon dioxide. Most fats are stored as fatty acids in the liver, which release them into the bloodstream when there is activity.