LESSON 1-ASSIGNMENT
1. Define each following terms in no more than 2 sentences each:
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Food: material usually plant or animal that contains or consists of essential body nutrients such as
Carbohydrates, Proteins, Fats, Minerals and Vitamins and is ingested and assimilated by an organism to produce
energy, stimulate growth and maintain life.
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Nutrition is the process by which organisms take in and utilize food material or/ and the act of nourishing or
being nourished.
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Diet is the usual food/drink of a person/animal/community habitually eats or/and a regulated selections of
food as qualities, composition and effects on health.
3. The following 5 nutrients each have specific roles in the maintenance of good health. Give a one sentence
definition for each, then, in no more than half a page, describe some ways each contributes to good health:
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Carbohydrates: Mainly sugars and starches, together constituting one of the three principal types of
nutrients used as energy sources (calories) by the body. Carbohydrates can also be defined chemically as
neutral compounds of carbon, hydrogen and oxygen. Carbohydrates come in simple forms such as sugars
and in complex forms such as starches and fiber. The body breaks down most sugars and starches into
glucose, a simple sugar that the body can use to feed its cells. Complex carbohydrates are derived from
plants. Dietary intake of complex carbohydrates can lower blood cholesterol when they are substituted for
saturated fat. Carbohydrates are classified into mono, di, tri, poly and heterosaccharides. The smallest
carbohydrates are monosaccharides such as glucose whereas polysaccharides such as starch, cellulose
and glycogen can be large and even indeterminate in length. The energy produced by carbohydrates is 4
calories per gram. Proteins also provide 4 calories per gram. Fats are high-cal; they provide 9 calories per
gram. Main Roles of Carbohydrates: 1) Supply Energy to the body uses carbohydrates directly from the
monosaccharide glucose. Glucose is in the blood and extracellular fluids (lymph) and can be made from
glycogen. Glycogen is stored in the liver and muscles and in smaller amounts in the other organs and tissues
of the body. Energy is derived from glucose by the splitting of the glucose molecules into smaller compounds
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and oxidizing these to form water, which frees quite a large amount of energy. When carbohydrates needed
for the functioning of the central nervous system, the muscles and the other body systems and functions are
insufficient in the diet (as during a fast or on a weight-loss diet), stored adipose tissue (fat) is broken down
into glucose to make up the caloric deficit. Some amino acids, instead of being used to make proteins, are
deaminated (removal of an amine group from a molecule) and used as carbohydrates to supply energy. The
formation of glucose from amino acids is called gluconeogenesis. This phenomenon enables one to maintain
normal blood sugar levels during a fast. Practically the entire fat store of the body can be used up without
detriment to health. Because of this fact, and the fact that the body can also create carbohydrates from
amino acids. 2) Help to regulate protein and Fat metabolism( Fat requires Carbohydrates to breakdown
within liver).3) Carbohydrates Supposedly Supply "Dietary Fibre" : Fibre is a component of the cell walls of
plants and helps hold the plant together. Although most fibres are carbohydrates they cannot be digested by
the human body so fibre does not contribute calories to one’s diet. There are actually two primary types of
fibre – soluble fibre and insoluble fibre. Dietary fibre is derived from plant sources such as fruits, vegetables,
and grains and contributes to a healthy diet and lifestyle. Most people consume different types of fibre daily
without realizing it. Whole-wheat breads, pears and carrots each contribute fibre to the diet, but the benefit of
each will vary. By eating a varied diet of fruits, vegetables, whole grains & cereals, and legumes, one can
incorporate different types of fibre in one’s diet. 4)The functions of fibre will vary depending on the type of
fibre. Psyllium and flax seed are insoluble fibres; guar gum and fruit pectins are soluble fibres. Insoluble
fibres are like sponges; they absorb and hold water adding bulk to stool which improves bowel movements,
and as they pass through the colon, insoluble Fibres help cleanse the interior walls of the bowels. Scientific
research has shown that this cleansing action may help prevent colorectal cancers and diverticulitis
(bacterial infection of the diverticula, tiny pockets in the small intestine). Soluble fibres, such as in fruit
pectins and guar gum, are helpful in preventing atherosclerosis by reducing high cholesterol and
triglycerides, thereby decreasing one’s risk of heart disease and stroke.
Protein: Formed by amino-acids, next to water, protein is the most plentiful substance in the body. It is of
primary importance in the development and growth of body tissues. Protein is also needed for the formation
of hormones and to control your rate of metabolism. An important use of protein for women is the formation
of milk during lactation and also in blood clotting. The amounts vary in all of us but excess protein that is not
used for building tissue is stored as fat in the body, protein requirements will differ due to body size and
activity level. Obviously someone who works out more intensely will require a higher amount to assist in
muscle growth. Protein-containing foods are grouped as either complete (found in animal foods such as
meat, fish, poultry, eggs, milk, and milk products such as yogurt and cheese and soybeans are the only plant
protein considered to be a complete protein) or incomplete proteins lack one or more of the essential amino
acids (beans, peas, nuts, seeds, and grain). Plant proteins can be combined to provide all of the essential
amino acids and form a complete protein. Examples of combined, complete plant proteins are rice and
beans, wheat cereal, and corn and beans.
Fats or Lipids: Fats are the most concentrated source of energy in our diet. When these are oxidized they
furnish more than twice the number of calories per gram furnished by protein or carbohydrates, there are
three types of Fats: Triglyrids, Phospholipids and Sterols. Many people think the word fat is a bad thing, but
actually fat deposits surround, protect and hold in place organs like the heart, kidneys and liver. They also
preserve body heat. One source of fats are milk products, eggs and cheese. The substance that give fats
their different flavours are known as fatty acids. There are two types, saturated and unsaturated. Rarely is
there a deficiency of fat which could lead to eczema or skin disorders however, excessive amounts of fat in
the diet can lead to abnormal weight gain if more calories are consumed than needed. One side affect of this
is slow digestion and absorption, which results in indigestion.
Water: This is the most important nutrient found in the body. It's also two-thirds of your body weight. You
know the old adage that you can live without food but not water. Water has many important values. It helps
to transport other nutrients throughout the body and helps to regulate the body temperature, while carrying
waste out of the body. The rate of water loss depends on the amount of activity. That's why during and
intense training session, it's important to keep drinking. Just keep reminding yourself that if you're perspiring,
keep drinking. Technically, the body contains approximately 45 quarts of water and loses about 3 quarts
daily. An important fact to remember is a deficiency in water intake can result in dehydration and salt
depletion. Aside from that, water is essential in keeping your bowel movements regular.
Vitamins: They are an important nutrient in that they help to regulate metabolism as well as converting fat
and carbohydrates into energy. With only a few exceptions, vitamins cannot be synthesized; they must be
supplied by in the diet by supplements. It's important that you get hold of a vitamin chart to keep around and
familiarize yourself with all that are available. If you browse through any health food store, it's pretty
overwhelming. The fact is, all natural vitamins are found only in living things such as plants and animals.
Minerals: These nutrients are vital to overall mental and physical well-being. They act as a catalyst with
metabolism and muscle response as well as the production of hormones. They are also vital in maintaining
water balance and add in permitting the other nutrients to pass into the bloodstream. It's important to become
familiar with nutrients such as calcium and chlorine, mainly due to their deficiency symptoms. Some of these
are brittle and softening of the bones as well as hair and teeth loss. Also slow growth rate and glucose
intolerance.
Congratulations Clo on completing your first assignment. I have found that you are grasping the subject as
required. Your answers are descriptive, show understanding of the concepts as well as application. Well
Done Keep it up!
Vahini