Download Fatty Acids

ThiQar college of Medicine
Family & Community medicine dept.
Nutrition Lecture 3
Third stage
Thursday ,December 1st,2016
CHARBOHYDRATES
 carbohydrate One of the three macronutrients, a
compound made up of carbon, hydrogen , and provides
energy.
 Recommended Dietary Allowance (RDA) for adults
19 years of age and older is 130 g of carbohydrate per day.
 The Acceptable Macronutrient Distribution Range
(AMDR) for carbohydrate is 45–65% of total daily energy
intake.
 Carbohydrates can be classified as simple
(the sugars)or complex.
 Simple carbohydrates contain either one or
two molecules, whereas complex
carbohydrates contain hundreds to thousands
of molecules.
 Simple Carbohydrates Include
Monosaccharides and Disaccharides
 Glucose , Fructose, Galactose,and Ribose Are
Monosaccharides
 Glucose, Fructose, and Galactose are the three
most common mono-saccharides in our diet.
 Glucose is the most abundant monosaccharide found
in our diets and in our bodies. Glucose does not
occur by itself in foods but attaches to other sugars to
form disaccharides and complex carbohydrates. In
our bodies, glucose is the preferred source of energy
for the brain, and it is a very important source of
energy for all cells.
 Fructose, the sweetest natural sugar, occurs
naturally in fruits and vegetables. Fructose is
also called levulose, or fruit sugar.
 Galactose does not occur alone in foods. It joins
with glucose to create lactose, one of the three
most common disaccharides.
 Ribose is a five-carbon mono-saccharide.
Very little ribose is found in our diets; our
bodies produce ribose from the foods we eat,
and ribose is contained in the genetic material
of our cells: deoxyribonucleic acid (DNA)
and ribonucleic acid (RNA).
Lactose, Maltose , and Sucrose Are Disaccharides
 The three most common disaccharides found in foods are
Lactose, Maltose, and Sucrose.
 Lactose (also called milk sugar) consists of one glucose
molecule and one galactose molecule. Interestingly,
human breast milk has a higher amount of lactose than
cow’s milk, which makes human breast milk taste
sweeter.
 Maltose (also called malt sugar) consists of two
molecules of glucose. It does not generally occur by itself
in foods but rather is bound together with other
molecules.
 Sucrose is composed of one glucose molecule and
one fructose molecule. Because sucrose contains
fructose, it is sweeter than lactose or maltose.
Sucrose provides much of the sweet taste found in
honey, fruits, and vegetables. Table sugar, brown
sugar, powdered sugar, and many other products are
made by refining the sucrose found in sugarcane
and sugar beets.
Complex CHO
 complex carbohydrates contain many glucose
units.
 polysaccharides are compounds composed
of many monosaccharides linked together.
 oligosaccharides An intermediate string of
three to ten monosaccharides.
 Three types of polysaccharides are important in
nutrition: glycogen, starches, and fibers.
 Glycogen Is a Polysaccharide, it is the storage form
of glucose for animals, including humans.
 Starch is a Polysaccharide Stored in Plants, it is the
storage form of glucose in plants.
 Excellent food sources of starch include grains
(wheat, rice, corn, oats, and barley),legumes (peas,
beans, and lentils), and tubers (potatoes).
 Fibers: composed of long polysaccharide
chains; however, the body can not break down
fiber molecules.
 The Adequate Intake for fiber is 25 g per day
for women and 38 g per day for men.
 Dietary fibers : found in all plant derived
foods—vegetables, fruits, whole grains, and
legumes.
 Functional fiber: extracted from plants or
manufactured in a laboratory and have known
health benefits, like cellulose, pectin, and
psyllium.
 Fiber can also be classified according to its chemical
and physical properties as soluble or insoluble:
 Soluble Fibers dissolve in water, found in oats,
barley, and citrus fruits, soluble fibers associated with
protecting against heart disease and diabetes by
lowering blood cholesterol and glucose levels.
 Insoluble Fibers do not dissolve in water, Found
mostly in whole grains (bran) and vegetables, insoluble
fibers promote bowel movements and alleviate
constipation.
Benefits &Health effect of CHO
Benefits of CHO are an important energy source at rest and
during exercise and provide 4 kcal of energy per gram.
CHO are necessary in the diet to spare body protein and
prevent ketosis.
Health effects:
1- Nutrient Deficiencies (Empty-kcalorie foods that contain
high sugar such as cakes, candies, and sodas with no
other nutrients. .
2-Causes Tooth Decay
3-Can Lead to Unhealthy Levels of Blood Lipids
4-Contribute to Obesity
benefits of fiber consumption
1-Reduce the risk of colon cancer.
2-Prevent hemorrhoids, constipation, and other
intestinal problems.
3- Reduces the risk of diverticulosis
4- Reduce the risk of heart disease by blocking the
absorption of dietary cholesterol into the blood.
5- Enhance weight loss, as eating a high-fiber diet
causes a person to feel more full.
6- Lower the risk of type 2 diabetes
The lipids
 A group of organic substances that are insoluble
in water; lipids include triglycerides, phospholipids, and sterols.
 Acceptable Macronutrient Distribution Range
(AMDR) for fat is 20% to 35% of total energy.
 Triglycerides are the most common Food-based
lipid (95%).
 fats: lipids that are solid at room temperature
(77°F or 25°C).
 oils: lipids that are liquid at room temperature.
 Triglyceride A molecule consisting of three
fatty acids attached to a three carbon glycerol
backbone.
Fatty Acids
 Fatty acids (FA) are the simpler molecular
forms of lipids, an organic compound
composed of a carbon chain with hydrogens.
 Fatty acids may be saturated or unsaturated. Unsaturated
fatty acids may have one or more points of un saturation.
(That is, they may be monounsaturated or polyunsaturated.)
 Of special importance in nutrition are the polyunsaturated
fatty acids whose first point of un saturation is next to the
third carbon (known as omega-3 fatty acids) or next to the
sixth carbon (omega-6).
 fatty acids that fit this description are linolenic acid (omega3) and linoleic acid (omega-6).
 essential fatty acids (EFAs) Fatty acids that
must be consumed in the diet because they
cannot be made by the body. The two
essential fatty acids are linoleic acid and
alpha-linolenic acid.
 Linoleic acid, also known as omega-6 fatty acid, is
found in vegetable and nut oils such as sunflower,
corn, soy, and peanut oil.
 Alpha linolenic acid, also known as omega-3 fatty acid, It is
found primarily in dark green, leafy vegetables, flaxseeds and
flaxseed oil, soybeans and soybean oil, walnuts and walnut oil,
and canola oil.
 In fish, shellfish, and fish oils, the two omega-3 fatty acids
found are eicosapentaenoic acid (EPA) and docosahexaenoic
acid (DHA). Fish that naturally contain more oil, such as
salmon and tuna, are higher in EPA and DHA than lean fish
such as cod or flounder. Research indicates that diets high in
EPA and DHA stimulate the production of prostaglandins and
thromboxanes that reduce inflammatory responses in the body,
reduce blood clotting and plasma triglycerides, and thereby
reduce an individual’s risk of heart disease.
 Linoleic acid. The Adequate Intake (AI) for linoleic
acid is 14 to 17 g per day for men and 11 to 12 g per
day for women 19 years and older.
 • Alpha-linolenic acid. The AI for alpha-linolenic
acid is 1.6 g per day for adult men and 1.1 g per
day for adult women.
 phospholipids A type of lipid in which a fatty
acid is combined with another compound that
contains phosphate, phospholipids are soluble
in water.
 the body manufactures phospholipids, so they
are not essential to include in the diet.
 The most important phospholipid is lecithin.
 In the liver, lecithins combine with bile salts
and electrolytes to make bile.
Sterols
 Sterols are a type of lipid multiple-ring structure
found in both plant and animal foods and
produced in the body.
 cholesterol is the most common sterol that
occurs in our diets.
 Compounds made from cholesterol:
1-Bile acids
2-Steroid hormones (testosterone, androgens,
estrogens, progesterones, cortisol,cortisone, and aldosterone)
3-Vitamin D
 For perspective, the Daily Value for cholesterol is 300 mg/day.