Transcript Ch. 7 Nutrition for Life

Ch. 7 Nutrition for Life
Section 1 Carbohydrates, Fats, and
Proteins
Section 2 Vitamins, Minerals, and Water
Key Terms
• Nutrition: the science or study of food and the ways in
which the body uses food
• Nutrient: a substance in food that provides energy or
helps form body tissues and that is necessary for life
and growth
• Carbohydrate: a class of energy giving nutrients that
includes sugars, starches, and fiber
• Fat: a class of energy giving nutrients; also the main
form of energy storage in the body
• Protein: a class of nutrients that are made up of amino
acids, which are needed to build and repair body
structures and to regulate processes in the body
Key Terms
• Vitamin: a class of nutrients that contain
carbon and are needed in small amounts to
maintain health and allow growth
• Mineral: a class of nutrients that are chemical
elements that are needed for certain body
processes, such as enzyme activity and bone
formation
• Nutrient deficiency: the state of not having
enough of a nutrient to maintain good health
What Is Nutrition
• Nutrition is the science or study of food and
the ways in which the body uses food
– Study of how and why we make food choices
– Study of the nutrients foods contain
Six Classes of Nutrients
• There are six classes of nutrients in food:
– Carbohydrates
– Fats
– Proteins
– Vitamins
– Minerals
– Water
A Balanced Diet Keeps You Healthy
• To stay alive, healthy, and growing, a person must eat
and drink the right amounts of nutrients
• Eating too little food causes weight loss, poor growth,
and if severe enough death.
• But eating too much food can also cause illness
resulting from excess body fat
– Heart disease
– High blood pressure
– Chronic diseases and disorders linked to poor nutrition
• What you eat today not only affects how you look and
feel right now but also can affect your health in the
long term
Food Has Fuel for Your Body
• Food provides the fuel that runs your body
• The sum of the chemical processes that take place in
your body to keep you alive and active is called
metabolism
– Requires energy and nutrients
• The nutrients in food that provide energy are
carbohydrates, proteins, and fats.
• Vitamins, minerals, and water are also nutrients
needed for metabolism, but they do not provide
energy.
• The energy in food is measured in calories
• The number of calories in a food depends on the
amount of carbohydrate, fat, and protein it contains
Carbohydrates
• Found in foods such as fruit, milk, cookies, and
potatoes all which are made of the same thing
sugars
• Two types of Carbohydrates:
– Simple
– Complex
• Simple are made up of single or double sugar
molecules
• Complex made of many sugar molecules that are
linked together
Simple
• Glucose: a single sugar that circulates in the blood
(blood sugar); the most important sugar in the body
because it provides energy to the body’s cells; usually
found as a part of the double sugar sucrose or in starch
• Fructose: a single sugar that is called fruit sugar; is
sweeter that table sugar; found naturally in fruit and
honey; added to many sweetened drinks
• Lactose: a double sugar made by animals that is also
called milk sugar; found in dairy products
• Sucrose: a double sugar refined from sugar beets or
sugar cane that we call table sugar; found in candies
and baked goods and used as a table sweetener
Complex
• Starch: made of many glucose units linked
together; found in foods like potatoes, beans, and
grains
• Glycogen: made in the body; made of many
glucose units linked together; stored in the
muscle and liver of humans and animals; can be
broken down to provide a quick source of glucose
• Fiber: made of many glucose units linked
together; found in fruits and vegetables; cannot
be digested by humans; needed for a healthy
digestive system
Fats
• Is an essential nutrient
• You need fat in your diet for your body to
function properly
• Add to the texture, flavor, and aroma of food
• Belong to a class of chemical compounds called
lipids, which are fatty or oily substances that do
not dissolve in water
• Fatty acids are long chains of carbon atoms that
are chemically bonded to each other and are
attached to hydrogen atoms
Fats
• Saturated Fats are fats that are made up of saturated fatty
acids
– Solid at room temperature and come from animal foods such as
meat and milk
– Meat, whole milk, butter, ice cream
• Unsaturated Fats are fats that are made up of unsaturated
fatty acids
– Common in plants
– Liquid at room temperature
• Cholesterol
– Found in human and animal tissues
– Needed to make vitamin D, cell membranes, certain hormones,
and bile
– LDL “bad cholesterol”
– HDL “Good cholesterol”
– Found in foods such as meat, fish, poultry, eggs, and dairy
products
Four Fat Facts
1. Too little dietary fat can lead to a fatty-acid deficiency,
but eating too much of the wrong types of fats can
raise blood cholesterol levels
2. Fat in your adipose tissue cushions your body’s organs
and helps keep your body temperature stable
3. Fat is needed to make regulatory molecules in the
body such as certain types of hormones. Fat is also
needed to form the coating on nerves and the
membranes that surround body cells
4. Fats add to the taste and texture of food and help you
feel full for several hours after you have eaten
Proteins
• Your muscles, skin, hair, and nails are made up of mostly
protein
• Help build new cells and repair existing ones
• Needed to form hormones, enzymes, antibodies, and other
important molecules
• Proteins are made up of chains of molecules called amino
acids.
• 20 different amino acids make up body proteins
• 9 of the amino acids needed to make body protein cannot
be made in our bodies called essential amino acids, must
be eaten in your diet
• The other 11 can be made by the body and are called
nonessential amino acids
Complete and Incomplete Proteins
• Animal proteins such as meat, eggs, and dairy
products contain all the essential amino acids.
These proteins are therefore called complete
proteins.
• Most plant proteins, found in foods such as
legumes, grains, and vegetables, don’t have all
the essential amino acids or have smaller
amounts of some essential amino acids than are
needed by your body. These proteins are called
incomplete proteins
Vitamins
• Classified by whether they dissolve in fat or water
• Fat-Soluble Vitamins
– A, D, E, K
– Dissolve in fat, most can be stored in fat tissue and
remain in the body for a long time
• Water-Soluble Vitamins
– 8 B vitamins and vitamin C
– Not stored I the body well
– B vitamins do not provide energy, most are needed to
release energy from carbohydrates, fats, and proteins
Minerals
• More than 20 minerals are essential in small
amounts to maintain good health
• Mineral are a class of nutrients that are
chemical elements that are needed for certain
body processes, such as enzyme activity and
bone formation
• Review Table 3
Water
• 60% of your body is water
• Water is essential because it is necessary for
almost every function that keeps you alive
• Extra water cannot be stored in the body,
therefore water intake must balance what
your body loses
• Eight glasses a day (2.5 quarts)
• Water, juice, and low-fat milk are healthy
sources of fluid
Three Reasons Why Water Is
Important
1. It transports nutrients and oxygen through
the body and helps get rid of wastes from the
body
2. It provides the proper environment for the
body’s chemical reaction to occur
3. It helps regulate body tempature