4.
Each nutrient plays a specific and important role in
keeping the body healthy.
Fat is one of 3 nutrients that provide energy. The
other two are carbohydrates and proteins.
Lipid = a compound that is insoluble in water, but
soluble in an organic solvent (e.g., ether, benzene,
acetone, chloroform)
“lipid” is synonymous with “fat”
LIPIDS
5.
Include
fats, oils, and cholesterol, a rich source of energy and
found in the structure of fat cells
Fat
Solid at room tempreture
Oils
liquid at room tempreture
LIPIDS
8.
Saturated Fats
a lipid have no double bonds between carbons in chain
Monounsaturated
a lipid has two double bonds between carbons in chain
Polyunsaturated
a lipid has more than double bonds between carbons in
chain
Types of Lipids
10.
Trans fats - created by a process known as
Hydrogenation includes Hydrogen, heat and a
catalyst behave like saturated fat in the body
Types of Lipids
11.
Cholesterol
Is found in every cell in the body
Needed to make
bile acids
hormones
vitamin D
Types of Lipids
15.
Lipids are concentrated sources of energy (9 kcal/g)
Provide means whereby fat-soluble nutrients (e.g.,
sterols, vitamins) can be absorbed by the body
Structural element of cell, subcellular components
Components of hormones and precursors for
prostaglandin synthesis
FUNCTIONS OF LIPIDS IN THE
HUMAN BODY
17. • The first step to digestion is the
mastication or chewing of the
food item
18. DIGESTION OF
LIPIDS
• Food is rolled into a bolus and
swallowed (Deglutinated) into
the esophagus
• Lingual Lipases
19. DIGESTION OF
LIPIDS
• Stomach acids are released as
well as lingual and Gastric
lipase which initiates fat
breakdown to fatty acids and
partially digested fats.
20. DIGESTION OF
LIPIDS
• After being churned and digested by the
stomach. The resulting mixture chyme
now passes to the small intestine.
• When fat is present in the small intestine,
it stimulates the release of pancreatic
lipases and bile
• Both pancreatic lipases and bile further
breakdown fats for absorption.
24.
Dietary Recomendaions for Fat are that fat should
compose 10- 35% of the total amount of energy from
the individuals diet.
Saturated Fat (M- less than 30mg/ F – less than 20mg)
Cholesterol- less than 300mg
Dietary Recomendaions
25.
FAT INTAKE OF ACTIVE AND
INACTIVE INDIVIDUALS
Generally:
Active individuals have lower stores of body fat than
inactive individuals.
Women have higher body fat stores than men.
26.
FACTORS THAT CAN ENHANCE OR
INHIBIT FAT OXIDATION DURING
EXERCISE
IMPORTANCE OF DIETARY FATS
Fat meets energy needs:
Need 10 - 30% of total daily kcal as fat
Dietary fat:
Essential to human metabolism
Provides essential fatty acids:
a. Linoleic acid
b. Alpha-linolenic acid
28.
FACTORS THAT CAN ENHANCE OR
INHIBIT FAT OXIDATION DURING
EXERCISE
Two major sources for ATP production during
exercise:
carbohydrate
fats
(mixture of both fuels used)
29.
FACTORS THAT CAN ENHANCE OR
INHIBIT FAT OXIDATION DURING
EXERCISE
Sources of fat during exercise:
Stored fat:
Muscle fat
Adipose tissue
Lipoproteins in the blood
30.
FACTORS THAT CAN ENHANCE OR
INHIBIT FAT OXIDATION DURING
EXERCISE
Factors that determine the amount and source of
Fat used during exercise:
Fitness level
Type of exercise
Intensity and duration of exercise
Available fat reserves in the muscle
Composition of pre-exercise meal
Availability of stored carbohydrate or amount of
carbohydrate eaten during exercise
31.
FACTORS THAT CAN ENHANCE OR
INHIBIT FAT OXIDATION DURING
EXERCISE
Trained athletes use more fat than untrained
athletes during a standardized exercise task:
Increased blood flow and capillarization to
muscle, delivering more free fatty acids
Increased number and size of mitochondria and associated
oxidative enzymes for processing of
activated free fatty acids
Increased activation of free fatty acids and transport across
mitochondrial membrane
32.
FACTORS THAT CAN ENHANCE OR
INHIBIT FAT OXIDATION DURING
EXERCISE
Moderate exercise, 60-75 % VO2
Max of long duration:
Fat is the primary energy source
33.
Fats: Ergogenic aspects
Examples of research studies:
Venkatraman (1998) noted short term high fat diets may
improve endurance exercise performance at 60-80% VO2
max
Keins (2000) noted that varying periods of fat adaptation
followed by high carbohydrate diet, despite increased fat
oxidation and decreased carbohydrates oxidation during
submaximal exercise resulted in no ergogenic benefits
High fat diets not advised for long-term basis
34.
FACTORS THAT CAN ENHANCE OR
INHIBIT FAT OXIDATION DURING
EXERCISE
Moderate exercise, 60-75 % VO2
Max of long duration:
Fat is the primary energy source
35.
FACTORS THAT CAN ENHANCE OR
INHIBIT FAT OXIDATION DURING
EXERCISE
Exercise at 65% VO2 max
Fats , carbohydrates contribute almost equally
Exercise at > 85% VO2 max
a. Energy contribution from fats diminishes to <
25%
b. Muscle glycogen becomes preferred energy
source
36.
FACTORS THAT CAN ENHANCE OR
INHIBIT FAT OXIDATION DURING
EXERCISE
Within 90 to 120 minutes of high-intensity
aerobic exercise:
Glycogen stores significantly drop
The body shifts to an increased usage of free fatty acids ,
leading to a decrease in exercise intensity
37.
Fats: Ergogenic aspects
Fat loading:
Appears to be no benefit of consuming high-fat
meal several hours prior to performance
Consuming a high-fat diet for 1-2 days may impair
performance in high-intensity exercise
Chronic low- carbohydrates and high-fat diets:
Do not benefit performance in untrained individuals
Additional research is needed with highly-trained endurance
athletes
Research studies report conflicting results
38.
Fats: Ergogenic aspects
Examples of research studies:
Venkatraman (1998) noted short term high fat diets may
improve endurance exercise performance at 60-80% VO2
max
Keins (2000) noted that varying periods of fat adaptation
followed by high carbohydrate diet, despite increased fat
oxidation and decreased carbohydrates oxidation during
submaximal exercise resulted in no ergogenic benefits
High fat diets not advised for long-term basis
39.
Determining Percentage
Fat by weight
Determine the total weight of fat within the product.
Divide the total weight of Fat by the net weight and
multiply the value obtained by 100 to determine
percentage fat by weight.
40.
Determining Calories
from Fat
1 gram of fat is equivalent to 9 kilocalories/ units of
energy
Therefore, if Jane consumes 5 grams of Fat, the
energy obtained would be 5 multiplied by 9 which is
equal to 45 kcal.
If you want to determine the percentage fat in the
diet, first you must determine the total energy
provided by the chief nutrients.
41.
Jane had 10 grams of carbohydrates and 15 grams of
fat from the meal she had. How many calories did
she obtain from the meal?
Remember 1 gram of carbohydrate is equivalent to 4
kcal
Therefore: 10 x 4 = 40 kcal from CHO
15 x 9= 135 kcal from Fat
The total energy obtained is 40 kcal+135 kcal = 175kcal
Determining Total
Calories
42.
To calculate percentage energy from fat. Take the
calorie determined for fat and place that value over
the total Kcal then multiply by 100:
(Calories from Fat/Total Calories) x 100 = % kcal
from Fat
Determining Percentage
Energy from Fat
43.
Determining Percentage
Energy from Fat
200g x 4kcal/g = 800 kcal
CHO
69g x 4 kcal/g = 276 kcal
Protein
120g x 9kcal/g = 1080 kcal
from fat
Jane had 200g of Carbohydrates, 69 grams of Protein and 120
grams of fat. What percentage of the diet constitutes energy from
fat?
Total = 800 kcal + 276 kcal +
1080 kcal
= 2156 kcal
% Kcal Fat
(1080kcal/2156 kcal) x 100
= 51.1%
Notas do Editor
At the present time there appears to be no advantage to feeding a high-fat diet to athletes.
Not recommended for health.
Causes GI distress.
During exercise or starvation, when the need for fat as an energy source is high, insulin is low and lipolysis is high. The decrease of insulin during exercise occurs primarily because epinephrine and norepinephrine inhibit pancreatic insulin release. [high insulin inhibits fat lipolysis and oxidation – think fed state].