Nutrients to Build Body Tissues

CHAPTER 1: WHAT IS FOOD MADE OF?

In this chapter, you will study the basics of food, including what it is made from. Food can be anything that is edible to humans. Your food is made from a variety of substances called macronutrients. You might recognize these as carbohydrates, protein, and fat. All food is made from these three types of macromolecules. You also consume micronutrients like vitamins and minerals. You will be introduced to these basic food components and will learn what fiber is and why it is indigestible.

NUTRITION 101

Nutrition isn't just about food; it is about the interaction between the food you eat and your body. Food contains certain types of nutrients. The nutrients are the helpful parts of food; all nutrients are digestible to some degree. We use the term digestible to indicate food that you ingest, and that gets absorbed into your gastrointestinal tract. Much more happens to food after it is digested; you will learn a lot more about exactly how this all works.

Food is divided into carbohydrates, protein, and fats. Carbohydrates can be divided into sugars, starches, and fiber. They are combined together because they are made of the same simple sugar molecules. There is more than one type of fat as well. Fatty acids are the type of fat used to store energy in your body, while cholesterol is used to make vitamins and as part of the cell wall of each of your cells.

A nutrient, by definition, is any active chemical ingredient in your food that has a true role in your body. Nutrients must be digested by the GI tract before they can be used by our body. Micronutrients get their name because they are needed in very small quantities in your food. They do not add any energy to the body but are important in other ways.

Nearly all the food you eat is made from some mixture of nutrients. Even food you think of as being only made from protein, such as meat, contains other things, such as fat and

micronutrients. When you talk of the different types of food, you need to think of them as being made of some percentage of sugar, starch, fiber, fat, oil, protein, water, vitamin, and mineral. By the end of this course, you will know which food groups contain the different substances in food.

Food has three main purposes: to build body tissues, to produce energy for immediate use and storage, and to maintain health. You need to consume enough food to get all the essential nutrients to sustain life. Water is just as important to consume as any nutrients you can eat. There is no such thing as a nutrient better for you than any other. They each have their role in the body, so all nutrients are necessary in some balanced way. You also need to consume some fiber, even though none of it gets introduced beyond the digestive tract.

NUTRIENTS TO BUILD BODY TISSUES

Your body is made entirely of nutrients. You should know the approximate nutrient content of a typical adult human body. A person weighing 110 pounds or 50 kilograms will be approximately 68 pounds of water, 20 pounds of protein, 15 pounds of fat, and 6.6 pounds of minerals. You can see from this that protein is the main bodybuilding nutrient you need to eat. Are you surprised at how much of your body is fat? You need fat to keep your body warm, to build cells, and to store energy. The mineral in the greatest quantity in your body is calcium. You might remember calcium as being an important part of your bones and teeth.

Children need nutrients in order to grow and develop. A child's body is always growing and making new cells. Each cell divides into new cells that grow and need nutrients too. Children need different quantities of nutrients than adults because of their rapid growth and development. Women in pregnancy also need different amounts of nutrients than nonpregnant women because they are creating a life that needs nutrients as well. The pregnant body also has an increased need for nutrients for the growing uterus and breasts.

Adults do not keep the same cells throughout their lifetime. You are replacing cells all the time. Your skin cells, for example, are continually sloughed off and need to be