Download Power point topic 3.1 nutrition

Energy Systems
Nutrition
3.1.1 List the macronutrients and
micronutrients.
• Macronutrients include:
– Lipid (fat)
– carbohydrate
– protein
– water
• Micronutrients include:
– Vitamins
– Minerals
– Fiber
Macronutrients
• bulk of our diets providing the human body with
energy.
• RDA
– 50 -60% of carbohydrates
– 12 – 15% of protein
– less than 30% fat.
• water does not provide energy, needed in
adequate amounts to ensure that all our body
cells function properly.
ROLES OF CARBOHYDRATE
• Building blocks are monosaccharides.
• stored in the muscle and liver.
• Excess carbs can be converted and stored as
triglyceride (fats).
• Both carbohydrates and triglycerides are
mainly used as fuel sources.
Disaccharides and Polysaccharides.
• Disaccharide = 2 monosaccharides
• Polysaccharide= more than 2 monosaccharides
linked together
• These reactions are all condensation reactions
producing water.
ROLES OF LIPID/FAT
• Building blocks are Fatty Acids.
• Triglycerides (broken down lipid) is stored as
adipose tissue.
• Help absorb fat soluble vitamins
• Long term energy storage.
Structure of Fatty Acid.
Triglyceride.
• Fatty acids can be linked to glycerol by a
condensation reaction to produce lipids called
glycerides.
A maximum of three fatty acids can be linked to
one glycerol molecule, producing a triglyceride.
Triglyceride
Fats are stored in our bodies as triglycerides
Saturated & Unsaturated Fats
• Substituting saturated fats with unsaturated fats
helps to lower levels of total cholesterol and LDL
cholesterol in the blood.
examples of unsaturated: nuts, and
vegetable oils such as canola, and olive oils.
• Meat products contain both saturated and
unsaturated fats.
Saturated Fats
Unsaturated Fats
Type of bonds Consist of SINGLE bond
Consist of at least 1 DOUBLE bond
Recommended Not more than 10% of total calories
consumption per day
Not more than 30% of total calories per
day
Excessive consumption is not good
Health Effects because of their association with
atherosclerosis and heart diseases.
Unsaturated fats are considered good to
eat if you are watching your cholesterol.
Also high in antioxidants.
Saturated fats increase Low Density
Lipoproteins (LDL or bad
cholesterol) & Very Low Density
Lipoproteins (VLDL's).Sources of
Cholesterol
bad cholesterol are foods rich in
trans fatty acids, refined
carbohydrates, such as white sugar,
and flour.
Unsaturated fats increase High-Density
Lipoprotein (HDL or good cholesterol)
and decrease Low Density Lipoproteins
(LDL or bad cholesterol). Sources of
HDL include onions and Omega-3 fatty
acids like flax oil, fish, foods rich in
fiber like grains.
Butter, coconut oil, whole milk,
Commonly meat, peanut, butter, margarine,
found in cheese, vegetable oil, fried foods, &
frozen dinners
Avocado, soybean oil, canola oil and
olive oil, sunflower oil, fish oils walnuts,
flax, & red meats
Shelf Life
These are long lasting and do not
spoil quickly
Melting Point High
Physical state at Solid (Trans Fats & Saturated Fats)
room
temperature
Rancidity Low
Examples
Hydrogenated Oils, Butter,
Processed Meats
These spoil quickly
Low
Liquid (Monounsaturated &
Polyunsaturated Fats- Omega 3's & 9's)
High
Olive Oil, linoleic acid, alpha-linolenic
acid
ROLES OF PROTEIN
• Building blocks are amino acids.
• Build and repair our bodies tissues.
• Also called peptides (di, poly).
Peptides (proteins)
• dipeptide = two amino acids
• Polypeptide =more than two amino acids
• All peptides are formed by condensation
reactions.
Essential and a Nonessential amino
acid.
• The human body requires 20 naturally
occurring amino acids for its proper
functioning.
• There are 8 essential amino acids for humans:
phenylalanine, valine, threonine, tryptophan,
isoleucine, methionine, leucine, and lysine.
• They are called essential because the body
does not manufacture them but must be
ingested in the diet.
Proper diet should be balanced and must
include all the essential amino acids.
• Based on their content of amino acids, foods
are often classified as complete, partially
complete, or incomplete protein sources. In
order for a protein to be complete, it must
contain all of the essential amino acids.
• The body continually breaks down protein
molecules and rebuilds the resulting amino
acids into other usable chains required by
particular areas of the body.
• In addition to their main functions of building
needed proteins, amino acids also:
assist vitamins and minerals to do their jobs
enhance the use of vitamins & minerals
• An adequate diet must contain enough protein to
supply these amino acids. The generally accepted
sources of amino acids are meat and dairy products.
• However, the necessary amino acids can be supplied
on a vegetarian or vegan diet but good nutritional
planning is necessary to make sure of an adequate
supply.
• Certain combinations of cereal grains (wheat, corn, and
rice) along with legumes (beans, peanuts) will provide
a complete amino acid.
Water
Function
Hydration, need for chemical reactions
to take place in our bodies.
MICRONUTRIENTS
• very small amounts. vitamins, minerals and
trace elements.
• Essential nutrients, body cannot make itself.
must be ingested.
Vitamins
Function
Energy release from macronutrients
metabolism
bone & blood health
immune function
eyesight.
Examples
fat soluble A,D,E & K
water soluble B & C
Minerals/trace elements
Function
Bone & teeth, O2 transport, help metabolism,
acid-base balance, muscle function.
Examples
Calcium, sodium, potassium & iron.
Fiber
Function:
indigestible portion of food derived from plants to
aid in digestion.
Regulate blood sugar levels
Helps you become full faster, weight control
Examples:
Whole-grain breads, Beans, Fruits, Vegetables,
Nuts.
Dehydration Synthesis (Condensation)
Reactions & Hydrolysis Reactions
• Dehydration means to take water out. So
when you use dehydration synthesis, you are
building something up while taking water out.
• Hydrolysis is a chemical process where
molecules are split into two by adding a
molecule of water.
Describe current recommendations for a
healthy balanced diet.
The New Food pyramid
UK
Dietary Recommendations
• It is recommended that our diets are made up of 50 -60%
of carbohydrates, 12 – 15% of protein and less than 30%
fat.
• In conclusion, a healthy diet must include proteins,
carbohydrates and fats.
• Intake of saturated fats should be strictly limited,
as should intake of high glycemic index carbohydrates.
• Protein and fat nutrition must emphasize the essential
acids
• while carbohydrates shall include only those of low
glycemic index.
• Protein foods should also be chosen in consideration of the
fat content.
energy content per 100 g of carbohydrate,
lipid and protein.
• Carbohydrate = 1760 kJ
• Protein = 1720 kJ
• Fat =4000 kJ
• Both carbohydrates and lipids can be used for
energy storage in humans. Carbohydrates are
usually used for energy storage over short
periods and lipids for long term storage.
Recommended energy distribution of the dietary macronutrients
differs between endurance athletes and non-athletes.
• Depending on intensity and duration of exercise,
an athlete may regularly expend twice as much
energy as a sedentary person. Furthermore,
many sports are performed in environments that
can increase energy expenditures (cold, humidity,
altitude).
• Consequently, sporting activities can involve
additional energy expenditure ranging from
around 1,000 kilocalories/day (dancing, martial
arts) to as much as 7,000 kilocalories/day (longdistance cycle races, endurance treks).
• During prolonged, aerobic exercise, energy is
provided by the muscle glycogen stores –
which directly depend on the amount of
carbohydrates ingested.
• This is not the only reason why dietary
carbohydrates play a crucial role in athletic
performance; they have also been found to
prevent the onset of early muscle fatigue and
hypoglycaemia during exercise.
• By keeping carbohydrate intake high, an
athlete therefore replenishes his glycogen
energy stores, and reduces the risk of rapid
fatigue and a decline in performance.
• At the same time, carbohydrate intake should
not be so high as to drastically reduce the
intake of fat, because the body will use fat as a
substrate once glycogen stores are depleted.
• The use of body protein in exercise is usually
small, but prolonged exercise in extreme
sports can degrade muscle, hence the need
for amino acids during the recovery phase.