Consume, Digest, And SURVIVE!

Our body needs energy and nutrients to keep it going. Such energy and nutrients are present in food. Food is anything that is edible and beneficial for our body. Because foods usually contain a mixture of nutrients, we often categorize a food based on the most predominate nutrient found in the food.

Let’s consider the energy-containing nutrients of carbohydrates, protein, and lipids. These contain energy because they are organic. Being an organic means they are composed of a structure that consists of hydrogen, oxygen, and carbon. Living or once-living things, including plants and animals produce organic compounds. The carbon-containing structure identifies these nutrients as being organic. When these nutrients are oxidized (burned in the body), energy is released and available for use by the cells. Although vitamins are also organic, they do not provide energy for the human body. Only carbohydrates, proteins, and lipids are energy-yielding nutrients.

The energy released from food is measured in kilocalories (thousands of calories) or calories. Technically, a calorie is the amount of heat necessary to raise the temperature of a gram of water by 1 degree Celsius. When someone asks how much energy is in an 8-oz. glass of skim milk, the correct response is 90,000 calories or 90 kilocalories.

Energy-yielding nutrients provide different amounts of energy. Carbohydrates and protein each provides 4 kcalories per gram. Lipids contain more than twice as much energy and provide 9kcalories per gram.

Another energy-yielding substance is alcohol. Alcohol provides 7 kcalories per gram. Although alcohol provides energy, it is not considered a nutrient because the body does not need it. In fact, the body treats it as a toxin. The breaking down or metabolizing alcohol is not only stressful to the body but also uses essential nutrients that could be better used to nourish the body. Some studies suggest that moderate consumption of alcohol-containing beverages such as red wine may be protective of heart diseases. The beneficial components are most likely photochemical, non-nutritive plant substances found in the ingredients used to produce the alcoholic beverages.

Although protein, lipids and carbohydrates provide energy, they- along with the other three nutrient categories of vitamins, minerals and water- have other important functions. A brief introduction to each nutrient category follows.

Carbohydrates are major source of fuel. They consist of simple carbohydrates often called sugars, and complex carbohydrates that include starch and most fiber. Simple carbohydrates are found in foods such as white sugar, fruits and milk. Complex carbohydrates are found in cereals, grains, pastas, fruits and vegetables. All, except fiber, are broken down to units of glucose, which is one of the simple carbohydrates. Glucose provides the most efficient form of energy for the body, particularly for muscles and the brain.

Proteins, in addition providing energy, perform an extensive range of functions in the body. Some of these functions include roles in the structure of bones, muscles, enzymes, hormones, blood, the immune system, and cell membranes. The linking of amino acids in various combinations forms proteins. Twenty amino acids are required to create all the necessary proteins to maintain life.

Fats are the densest form of energy available in foods and as stored energy in our bodies. Fats, or lipids, serve other purposes, such as functioning as a component of all cell structures, having a role in the production of hormones, and providing padding to protect body organs. Essential fatty acids and the fat-soluble vitamins A, D, E, and K are found in food lipids. It is the fats in certain foods that make them taste so appealing.

Vitamins are compounds that indirectly assist other nutrients through the complete processes of digestion, absorption, metabolism, and excretion. Thirteen vitamins are needed by the body and each has a specific function. As noted earlier, vitamins provide no energy but instead assist in the release of energy from carbohydrates, lipids, and proteins.

Minerals serve structural purposes in the body and are found in body fluids. Minerals in body fluids affect the nature of the fluids, which in turn influence muscle function and the central nervous system. Sixteen essential minerals are divided into two categories: major and trace minerals. Although this distinction is based on the quantity of minerals required by the body, each is equally important.

Water is a major part of every tissue in the body. We can live only a few days without water. Water functions as a fluid in which substances can be broken down and reformed for use by the body. As a constituent of blood, water also provides a means of transportation for nutrients to and from cells.

Now you know more about the food you eat. It may be such a simple thing to do, but it is made up of complex materials that help us survive up to this moment.