Key Terms:
Nutrient: The substances in food that provide the raw materials and energy the body needs to carry out its essential processes.
Calorie: Is the amount of energy needed to raise the temperature of one gram of water by one degree Celsius.
Carbohydrate: An energy-rich organic compound made of the elements carbon, hydrogen, and oxygen
Glucose: A sugar that is the major source of energy for the body’s cells
Fat: Energy containing nutrients that are composed of carbon, oxygen, and hydrogen
Protein: Large organic molecule made of carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur
Amino Acid: A small molecule that is linked chemically to other amino acids to form proteins
Vitamin: Molecules that act as helpers in a variety of chemical reactions within the body
Mineral: Nutrients that are needed by the body in small amounts and are not made by living things
Percent Daily Value: A value that shows how the nutritional content of one serving of food fits into the diet of a person who consumes 2,000 Calories per day
Dietary Reference Intake (DRIs): Guidelines for the amounts of nutrients needed daily
Why You Need Food
Nutrients: The substances in food that provide the raw materials and energy the body needs to carry out its essential processes.
6 groups of nutrients:
Carbohydrates
Fats
Proteins
Vitamins
Minerals
Water
Energy:
When nutrients are used by the body for energy, the amount of energy they release can be measured in units called calories.
One calorie is the amount of energy needed to raise the temperature of one gram of water by one degree Celsius.
Calorie, with a capital C, is used to measure the energy in foods.
One Calorie is equal to 1000 calories, or 1 kilocalorie (kcal). I.e., one serving of popcorn may contain 60 Calories (60 kcal), or 60,000 calories, of energy. The more Calories a food has, the more energy it contains.
You need a certain amount of Calories each day to meet your body’s energy needs.
Your daily energy requirement depends on your level of physical activity.
The more active you are the greater your energy needs are.
Carbohydrates:
One gram = 4 Calories of energy, Provide raw materials to make cell parts
Two types of Carbohydrates:
Simple Carbohydrates
Complex Carbohydrates
Simple Carbohydrates:
Also known as sugars.
Glucose is one form of sugar that is a major source of energy for your body’s cells.
Most foods do not contain much glucose, so your body converts the types of sugars found in fruits and other foods into glucose
Glucose is the form of sugar the body can most easily use.
Complex Carbohydrates:
Made up of many sugar molecules linked together in a chain.
Examples of Complex Carbohydrates:
Starch (potatoes, rice, wheat, corn)
Fiber
Starch is broken down into smaller, individual sugar molecules in order for the body to get the energy from in.
Fiber is not considered a nutrient. The body cannot break it down. It passes thru the system and is eliminated. It is great for digestion system.
Nutritionist Recommendations:
45-65% of Calories should come from carbohydrates.
Complex carbohydrates > Simple carbohydrates.
Complex carbohydrates provide a long term energy source
Foods made with a lot of simple carbohydrates(sugar), i.e., candy, soda, have very few nutrients. They provide a quick burst of energy
Fats:
Energy-containing nutrients that are composed of carbon, oxygen, and hydrogen.
Contain more than twice the amount of energy of carbohydrates.
One gram of fat provides your body with 9 grams of energy.
Fats from fatty tissue that protects and supports your internal organs and insulates your body.
Kinds of Fats:
Unsaturated Fats
Saturated Fats
Trans Fats
Unsaturated Fats:
Usually liquid and room temperature, i.e., cooking oils
Beneficial for the human body in proper amounts
Saturated Fats:
Usually solid at room temperature
Meat and dairy products contain large amounts of saturated fats
Not beneficial for the human body
Trans Fats:
Made by adding hydrogen to vegetable oils.
Allows foods to stay fresh longer
Not beneficial for the human body
Banned in many cities in the United States
Cholesterol:
Waxy, fatlike substance found only in animal products
Cholesterol is an important part of your body’s cells.
Your liver makes the cholesterol your body needs, therefore it’s an unnecessary part of your diet.
Nutritionists Recommendations:
No more than 30% of the Calories eaten per day should come from Fats.
Diets high in fats and cholesterol can lead to buildup of fatty material in the blood and cause heart disease.
Proteins:
Nutrients that contain nitrogen, carbon, hydrogen and oxygen
Needed for tissue growth and repair
Play an important role in chemical reactions within cells
Proteins are a source of energy but not as much as carbohydrates and fats.
Amino Acids:
Amino acids are small units that link together to form protein molecules.
Thousands of different proteins are built from only about 20 amino acids.
Your body can make about half of the amino acids it needs, the other half, called essential amino acids, come from the foods you eat
Complete and Incomplete Proteins:
Foods from animal sources such as meat and eggs are sources of complete proteins because they contain all the essential amino acids
Plant sources, such as beans, grains, and nuts are called incomplete proteins because they are missing one or more essential amino acid.
To obtain all the essential amino acids from plant sources alone, one must a wide variety of plant foods.
Vitamins & Minerals:
Needed by the body in very small amounts.
They do not provide the body with energy or raw materials.
They help the body carry out various chemical processes.
Vitamins are only needed in small amounts but without them we can’t maintain good health.
Vitamins:
Help with a variety of chemical reactions, i.e., vitamin K helps the blood to clot when your bleeding.
The body can make a few vitamins, i.e., the body makes vitamin D when exposed to sunlight.
Most vitamins, however, need to be obtained by consuming foods.
Two types of Vitamins:
Fat-Soluble - vitamins that dissolve in fat and are stored in the body (vitamins A,D,E and K)
Water-Soluble - vitamins that dissolve in water and are not stored in the body. Need to be replenished daily (vitamins B and C)
Minerals:
Nutrients that are not made by living things.
Minerals are present in soil and absorbed by plants through their roots.
You obtain minerals by eating plant foods or animals that have eaten plant foods.
Water:
The most important of all nutrients.
The body can only survive a very short period of time without it.
The most abundant substance in the body
65% of the body weight.
The body’s chemical reactions and breaking down of nutrients happen in water.
Nutrients are carried throughout the body by being dissolved in the watery part of the blood.
The water in blood also carries waste materials that must be removed from the body.
Perspiration or sweat consists of chemicals dissolved in water
Perspiration helps regulate and cool the body temperature.
Nutritionist recommendations:
The human body needs about 2 Liters of water per day on average.