Notes

Apples and oranges are good sources of carbohydrates. Carbohydrates are the body's primary and immediate source of energy. Each gram of carbohydrate provides the body with 4 Calories. A Calorie (spelled with a capital "C") is the amount of heat needed to raise the temperature of 1 kilogram of water 1 degree Celsius. This unit of heat measurement is equivalent to a kilocalorie in scientific measure. If you were to walk for an hour, for example, you would burn approximately 200 Calories. That means various cells in your body would need to convert 50 grams of carbohydrates into glucose to provide the energy needed to walk an hour.

Carbohydrates are "burned" in the form of glucose. During digestion, complex carbohydrates are broken down into glucose units. Glucose is then absorbed by cells and used for energy during metabolism. Unused glucose is sent to the liver, where it is stored for later use as fuel. In the liver, glucose is stored as glycogen, a form of starch.

Carbohydrates exist in abundance in foods that contain starch and sugar. Foods, such as pasta, bread, corn, potatoes, beans, fruits, table sugar, honey, and candy, are high in carbohydrates. However, not all carbohydrates affect the body in the same way. Complex carbohydrates require a prolonged process of digestion in order to be broken down into glucose. This extended process helps to maintain proper "blood sugar" levels.-Simple carbohydrates are found in foods, such as candy, table sugar, honey, and maple syrup. Because their chemical make-up is similar to that of glucose, they do not take long to digest. They are quickly converted into glucose and immediately absorbed by cells. As compared with complex carbohydrates, simple carbohydrates cause blood sugar levels to rise at a rapid rate. To control the effects of sugar in the blood, the body releases insulin, a hormone produced by the pancreas to help muscle cells utilize glucose. However, after the glucose has been absorbed, blood sugar levels can also fall at a rapid rate. Eating simple carbohydrates can leave one feeling tired and sluggish and often craving for more simple carbohydrates. The consumption of carbohydrates should be limited to complex carbohydrates.-FATS

Another source of energy is fat. Fat is the most concentrated form of energy, yielding 9 Calories per gram. Because of its role in the absorption of vitamins, the protection of vital organs, and the digestion of other foods, fat is essential to good health.

There are two types of dietary fats, saturated and unsaturated. Dietary fats are fats that are eaten, as opposed to the fat found in your body. Saturated fats are found in animal products, such as meat, cheese, lard, and butter, and some plant oils, such as coconut oil and palm oil. Unsaturated fats are found in vegetables or nuts. Peanuts, olives, sunflower seeds, avocados, olives, and corn contain unsaturated fats.

Both unsaturated and saturated fats contain fatty acids. Fatty acids are organic acids that aid in the transportation and breakdown of cholesterol. Cholesterol is used by the body to synthesize Vitamin D, to maintain the proper functioning of nerve cells, to keep skin soft and supple, and to transport fat to cells.

Certain fatty acids are termed "essential" because they cannot be produced by the body. Therefore, eating foods that contain fats are vital to good health.
PROJECT: GOT CALCIUM?
As a growing adolescent, you need to consume about 1200 mg of calcium each day in order to build healthy bones and teeth. Do you consume that much calcium each day? If you don't, you could be growing weak and brittle bones. Weak and brittle bones do not hold up well under pressure and are susceptible to breaks and fractures. In this activity, you will calculate the average amount of calcium that you consume each day. Record your results. Refer to the table shown for an example of how to record your data.



Step 1: Think back over the last two days and record the dairy products that you have eaten. Other foods also contain calcium; however, dairy products are the richest source and are the easiest to record.
Step 2: Record your calcium sources under "Food Source."
Step 3: Using the chart above and/or the product's food label, record the amount of calcium consumed under "Calcium."
Step 4: Total the amounts for each day.
Step 5: Figure your average daily calcium intake by adding the two totals and dividing by two.
Step 6: Compare your total with the RDA for an individual your age.



Day 1: Food Source: Calcium
Breakfast:
Lunch:
Dinner:
Snacks:
Total: mg
Day 2: Food Source: Calcium
Breakfast:
Lunch:
Dinner:
Snacks:
Total: mg
Day 1 Total: _____ mg + Day 2 Total: _______ mg = _______ ÷ 2 = ________ mg of calcium per day.

How did your average amount compare with the RDA? More? Less? Equal?
If your totals were less than the RDA, what are some healthy ways that you can add calcium to your diet?

Fats are also essential to the absorption of Vitamins A, D, E, and K, and play a crucial role in the development of healthy bones, teeth, and skin. Any fats that are consumed (unsaturated or saturated) beyond the body's needs are stored in tissue under the skin and around vital organs. These layers helps to insulate the body from extreme temperatures and protect organs and bones from injury.-
PROTEINS

Every cell, every tissue, and every organ consists mainly of protein. It is the second most abundant substance in the body. Protein is essential to cellular construction, reproduction, and maintenance. It can also be used for energy.

Proteins consist of smaller units, known as amino acids. There are 22 different amino acids utilized by the body, eight of which must be derived from food sources. The eight amino acids are considered "essential."

A protein source that contains all the essential amino acids is considered a "complete protein." Some of the best sources of complete proteins are found in animal proteins. Plant sources can also supply complete protein, making sure the combination of these sources contain all the essential amino acids. Rice and beans, corn and beans, or milk with wheat cereal all can be classified as complete proteins. Although meat is a complete protein source, it is important to limit the amount of meat eaten due to the saturated fat that accompanies the protein. As with any part of a complete diet, balance is important to successfully build, repair, and maintain a healthy body.