Life Cycle - Human Biology (5A) Lab
 OBJECTIVES: Calculating calorie intake.  Analyzing how calories are used. VOCABULARY: calorie carbohydrate fat       mineral protein vitamin  MATERIALS: The Ultimate Calorie Counter by S. Buff internet calorie calculators Students calculate how many calories they ate.
BACKGROUND:

Proper food is essential for the maintenance or restoration of health.  There are six classes of food substances: carbohydrates, fats and oils, proteins, minerals, vitamins, and water.

A calorie is a unit of heat used to measure body metabolism and  "how fat" individual foods will make you.  Technically, a calorie is the amount of heat necessary to raise the temperature of one kilogram (2.2 pounds) of water one degree Centigrade.  Emphasize with students that a calorie is not a nutrient or a substance but a measure of food composition and heat energy.

Carbohydrates and fats are the chief sources of calories; proteins may also furnish calories.  One gram (one-thirtieth of an ounce) of these nutrients, when burned in the body, supplies the following number of calories:

 carbohydrate 4 calories fat 9 calories protein 4 calories

It is evident that fat is a concentrated source of calories.  It is easy to understand then, why reduced intake of fats is advised for those who are overweight and wish to lose weight.  Alcohol is also a concentrated source of calories, supplying 7 calories/gram and the familiar "beer belly".

The amount of calories needed for body functions  varies with age, sex, activity, and climate.  Boys are usually move active and larger than girls and require more calories.  If you eat more calories per day than you use in your body, the excess is changed to fat and stored in the body. Fifth grade students need between 2000 to 3000 calories, depending on activity.  You will become overweight if you continually eat more than your body needs.

PROCEDURE:
1. In lab the students will use the calorie charts that you can download in many places on the internet (use a search engine) to determine how many calories they ate within a 24 hour period.  Students will have to break down some of their foodstuff, for instance, a hamburger would be ground beef, catsup, and bread.  This lab may take a while to do, but will prove very informative as to what your students are eating.  Many students do not realize that the more they eat, the more weight they gain.

2. Make sure that you go over how to read the book.  You may have to give students a few examples, like peanut butter and jelly sandwiches or half of an apple

3. Students will have to remember what they ate the day before, so a reminder the day before the lab would be appropriate.