What Food Does and How it Moves Through the Body

The human body is designed to run off of the nutrients provided to it by way of food and drink. These nutrients are water, carbohydrate, fat, protein, vitamins, and minerals. These nutrients are provided to the body in different amounts depending on what is eaten and the quantity in which it is eaten. The digestive system breaks down food into the nutrients the body needs before excreting the waste.

Water is a vastly important macronutrient. Since water is constantly leaving the body, it must be replenished. The most direct way to replenish water is to drink enough water throughout the day. However, water can also be provided in smaller amounts through the food we eat. Water is a pretty important part of the digestive system as it softens food for easier consumption, lubricates the organs and helps food move easily through the digestive system all the way to the end.

One important source of energy comes from the nutrients provided by carbohydrates. Starchy foods, such as potatoes or corn, as well as fruits, vegetables, breads, and dairy products provide carbohydrates to the body to use as energy. (Chapman-Novakofski, 2014) To process carbohydrates into useable nutrients, the digestive system begins to break down starches in the mouth with saliva. In the small intestine, the digestive system breaks down starches and disaccharides into monosaccharides which can then be absorbed through the cell linings. (Sizer & Whitney, 2014)

Fat is another energy yielding nutrient. Fats, which are also called lipids, are ingested through dairy, meat, bread and oils or butter products. While fat is a necessary nutrient, too much fat, or the wrong kinds of fats can be detrimental to overall health and lead to heart disease. It is suggested that individuals focus on eating monounsaturated and polyunsaturated fats and avoiding trans fat and saturated fat. Fat tends to not mix well with other foods in the stomach, so it isn’t until it gets to the small intestine and bile from the gallbladder is emulsified with it, that fat begins its digestion process. Once the fat has been emulsified, it begins to be broken down into absorbable pieces. These pieces are shuttled by bile through the watery mucus layer of the digestive tract to the “absorptive surfaces on cells of the intestinal villi.” (Sizer & Whitney, 2014, p. 165)

Protein is the third energy-yielding nutrient but it also provides amino acids to the body so “that the body can synthesize new proteins such as enzymes or hormones, or structural proteins to build muscle.” (Chapman-Novakofski, 2014) The best sources of protein for individuals is through meat, however, protein can also be found in beans, nuts, dairy, and most foods with the exception of foods that are all fat, or all sugar. To digest protein, teeth crush it into pieces small enough to swallow. However, in the stomach, acid starts to break down the protein strands into smaller pieces. After the stomach, those strands are pushed into the small intestines, where the pancreas excretes alkaline juice to neutralize stomach acid so that the final strand breakdown can occur. (Sizer & Whitney, 2014) Almost all of the protein will be broken down into single amino acids, or short strands of amino acids called dipeptides and tripeptides. The cells of the small intestine absorb the single amino acids while the dipeptides, and tripeptides are split by enzymes on the cell’s surface for absorption into the blood stream. Once in the bloodstream, the amino acids head to the liver to be used, or released into the blood for the use of other cells. (Sizer & Whitney, 2014)

As with water, vitamins and minerals provide no energy to the body. (Sizer & Whitney, 2014) However, vitamins and minerals play important roles, acting as regulators and assist in all body functions. (Sizer & Whitney, 2014) Minerals important to the body include, calcium, magnesium, sodium and potassium. Minerals cannot be destroyed with cooking or processing and minerals vary in foods by the soil foods are grown in and fed to animals. The mineral calcium, for instance is found in dairy products and helps promote bone growth and development. Potassium, along with sodium, works to maintain fluid balance in the body. A great, and popular source of potassium is through bananas. Vitamins can be impacted by cooking or processing foods. There are many different types of vitamins that the body uses and they perform various functions. Vitamin A can come from animal and plant sources and is required for good vision. (Chapman-Novakofski, 2014)

 

Nutrients are an essential part of life. They are provided by the food we eat and each nutrient has a purpose in the body which is expertly broken down into useable pieces by the digestive system. While only three nutrients are energy-yielding, they all work together to keep an individual properly functioning and each nutrient must be present.

References

Chapman-Novakofski, K. (2014). Nutrition. Salem Press Encyclopedia of Science.

Sizer, F. S., & Whitney, E. N. (2014). Nutrition: Concepts & controversies. Belmont, Calif.: Wadsworth Cengage Learning.