What are Essential Nutrients?
Definition: Essential Nutrients are those substances the body must get from food
because it cannot manufacture them on its own or fast enough to meet its needs.
Six Classes of Nutrients:
1) Proteins
2) Carbohydrates
3) Fats
4) Vitamins
5) Minerals
6) Water
*Proteins
Protein should make up about 15% of your daily diet. They form the important
parts of the body’s main structural components: muscles and bones. Also, they
provide energy at 4 calories per gram of protein. The building blocks of proteins
are called amino acids. The leading sources of protein in America are meat, fish,
poultry, eggs, milk products, legumes, and nuts.
*Carbohydrates
Carbohydrates supply energy to cells in brain, nervous system, blood, and the
muscles during exercise. They provide energy at 4 calories per gram of
carbohydrates. There is a lot of hype in the news today about “low-carb” or “nocarb”
diets, but actually carbs are supposed to make up the majority, or about
55%, of your daily calorie intake. True, you may lose weight if you go strictly on
a high protein/fat diet, but this weight will all be regained once you start eating
carbs again so it is not a good long term solution. Carbohydrates can be obtained
from grains (breads and cereals), fruits, vegetables, and milk.
-2 Types of Carbohydrates:
1) Simple-contain only one or two sugar units in each molecule; they include
sucrose (table sugar), fructose (fruit sugar, honey), maltose (malt sugar), and
lactose (milk sugar).
2) Complex-consist of chains of many sugar molecules; they include starches
and most types of dietary fiber. Starches are found in a variety of plants and
especially grains (wheat, rye, rice, oats, and barley). Dietary fiber is found in
fruits, vegetables, and grains.
Complex carbs can be defined as either refined or whole grain. Refined grains are
those that have had some of the nutrients taken out of them. For example, white
flour is just wheat flour that has had the germ and bran removed. Try to
incorporate as many whole grains in your diet as possible. Some good choices
are brown rice, whole wheat bread, popcorn, or oatmeal.
*Fats
Fats are the most concentrated source of energy, at 9 calories per gram. The fats
stored in your body represent usable energy, help insulate your body, and
support and cushion your organs. Food fats are often composed of both
saturated and unsaturated fatty acids; the dominant type of fatty acid determines
the fat’s characteristics.
-Food fats containing large amounts of saturated fatty acids are usually solid at
room temperature and are generally found naturally in animal products. The
leading sources of saturated fat are red meats (hamburgers, steak, and roasts),
whole milk, cheese, hot dogs, and lunch meats.
-Food fats containing large amounts of monounsaturated and polyunsaturated fatty
acids are usually from plant sources and are liquid at room temperature. Olive,
canola, safflower, and peanut oils contain mostly monounsaturated fatty acids.
Corn, soybean, and cottonseed oils contain mostly polyunsaturated fatty acids.
A particularly harmful type of fat is trans fatty acids which form when
unsaturated vegetable oils undergo hydrogenation. Food manufacturers use this
to increase the stability of oil so it can be reused for deep frying to improve the
texture of certain foods and to extend the shelf life of foods made with oil.
Hydrogenation is also used to transform liquid vegetable oils into margarine or
shortening. Leading sources of trans fats are deep-fried French fries and chicken,
baked and snack foods such as pot pies, cakes, cookies, pastries, doughnuts, and
chips, and stick margarine. Check labels for “partially hydrogenated oil” in the
ingredient list.
-Omega-3 Fatty acids are a form of polyunsaturated (or good fat) fat found
primarily in fish. They reduce the tendency of blood to clot, inhibit inflammation
and abnormal heart rhythms, and reduce blood pressure and risk of heart attack
and stroke in some people. Salmon, tuna, trout, sardines, and anchovies are all
good sources of omega-3’s; lesser amounts are found in plant sources, including
dark-green leafy vegetables, walnuts, flaxseeds, and canola, walnut, and flaxseed
oil.
The 2000 Dietary Guidelines for Americans recommend that most people limit
their total fat intake to 30% or less of total calories, with less than 10% coming
from saturated fat. For example, if you consume 2200 calories per day, you
should limit your total fat intake to 73 grams per day, of which no more than 24
grams should be saturated fat. In reducing fat intake to recommended levels, the
emphasis should be on lowering saturated and trans fats. You can still eat highfat
foods, but it makes sense to limit the size of your portions and to balance your
intake with low-fat foods.
*Dietary Fiber
Dietary Fiber consists of carbohydrate plant substances that are difficult or
impossible for humans to digest. It provides bulk for feces in the large intestine,
which in turn facilitates elimination. Dietary fiber can be classified as either
soluble or insoluble which each contribute to disease prevention.
-Soluble Fiber- slows the body’s absorption of glucose and binds cholesterolcontaining
compounds in the intestine, lowering blood cholesterol levels and
reducing the risk of cardiovascular disease.
-Insoluble Fiber- binds water, making the feces bulkier and softer so they pass
more quickly and easily through the intestines.
Both kinds of fiber contribute to disease prevention. A diet high in soluble fiber
can help people manage diabetes and high blood cholesterol levels. A diet high
in insoluble fiber can help prevent a variety of health problems, including
constipation, hemorrhoids, and diverticulitis. All plant foods contain some
dietary fiber, but fruits, legumes, oats, and barley are particularly rich in it.
Currently, most Americans consume about 16 grams of fiber a day, whereas the
recommended daily amount is 20-35 grams of fiber.
*Vitamins
Organic (carbon-containing) substances required in very small amounts to
regulate various processes within living cells. Humans need 13 vitamins. Four
are fat-soluble (A, D, E, and K), and nine are water- soluble (C, and eight B-complex
vitamins: thiamin, riboflavin, niacin, vitamin B-6h, folate, vitamin B-12, biotin,
and pantothenic acid.)
-Water Soluble- are absorbed directly into the bloodstream where they travel
freely; excess are detected and removed by the kidneys and excreted in urine.
-Fat Soluble- are usually carried in the blood by special proteins and are stored
in the body in fat tissues rather than excreted.
The human body does not manufacture most of the vitamins it requires and must
obtain them from foods. Vitamins are abundant in fruits, vegetables, and grains.
To reduce nutrient losses in vegetables during cooking, minimize the amount of
water used and the total cooking time.
*Minerals
Inorganic elements you need in small amounts to help regulate body functions,
aid in the growth and maintenance of body tissues, and help release energy.
There are about 17 essential minerals. The major minerals, those that the body
needs in amounts exceeding 100 milligrams, include calcium, phosphorus,
magnesium, sodium, potassium, and chloride. The minerals most commonly lacking
in the American diet are iron, calcium, and zinc. Lean meats are rich in iron and
zinc; low-fat and fat-free dairy products are excellent choices for calcium. Plant
foods such as whole grains and leafy vegetables are good sources of magnesium.
Anemia (low iron) and osteoporosis (low calcium) are two of the main diseases that
result from a diet low in minerals.
*Water
Is the main component in both foods and the human body; you are composed of
about 60% water. You can live up to 50 days without food, but only a few days
without water. It is used in digestion and absorption of food and is the medium
in which most of the chemical reactions take place within the body. Water is
contained in almost all foods, particularly in liquids, fruits, and vegetables. The
foods and fluids you consume provide 80-90% of your daily water intake; the
remainder is generated through metabolism. You lose water each day in urine,
feces, sweat, and evaporation in your lungs. To maintain a balance between
water consumed and water lost, you need to take in about 64 ounces of water per
day. Thirst is one of the body’s first signs of dehydration that we can recognize.
By the time we realize we are thirsty, our cells have actually been needing fluid
for quite some time. A good motto to live by is: Drink before you are thirsty!