Unit 1 Topic 1 ~Lifestyle, health and risk~ ~balanced diet and energy budget~ Prepared by: Ilyanie Hj. Yaacob Biology ~ A-Level.
8/7/2019 11 - balanced diet and energy budget
http://slidepdf.com/reader/full/11-balanced-diet-and-energy-budget 1/30
Unit 1 Topic 1~Lifestyle, health and risk~
~balanced diet and energybudget~
Prepared by:Ilyanie Hj. Yaacob
Biology ~ A-Level.
8/7/2019 11 - balanced diet and energy budget
http://slidepdf.com/reader/full/11-balanced-diet-and-energy-budget 2/30
Daily nutrients human beings need in order to grow and k eep
healthy :
Macronutrients:
~ Carbohydrates~ Proteins
~ Fats (lipids)
Micronutrients
~ Mineral salts
~ Vitamins
Water
Fiber
Ov er v iew
Food pyramid.
8/7/2019 11 - balanced diet and energy budget
http://slidepdf.com/reader/full/11-balanced-diet-and-energy-budget 3/30
8/7/2019 11 - balanced diet and energy budget
http://slidepdf.com/reader/full/11-balanced-diet-and-energy-budget 4/30
Food should provide appropriate amount of the six following
components:
1) Metabolic fuel.
From carbohydrates, lipids and/or protein provide energy.
2) Combined nitrogen.
Required for the building of proteins provided by proteins or amino
acids.3) water.
Significant part of diet is 70-90% of body consist of water.
B alance diet
8/7/2019 11 - balanced diet and energy budget
http://slidepdf.com/reader/full/11-balanced-diet-and-energy-budget 5/30
4 ) Dietary fibres.
Work as bulk that stimulates food movement through the alimentary
canal.
5) Essential minerals.
Needed for the construction of body tissues and essential for
metabolic processes.
6) Vitamins.Needed as coenzymes, as well as antioxidants in the body.
B alance diet
8/7/2019 11 - balanced diet and energy budget
http://slidepdf.com/reader/full/11-balanced-diet-and-energy-budget 6/30
Undernutrition :
A type of malnutrition caused by
inadequate food intake or the body's
inability to make use of needed nutrients.
not enough food, sufficient amino acids,
minerals and vitamin.
resistance to disease e.g.: kwashiorkor.
Im balance diet -undernutrition
8/7/2019 11 - balanced diet and energy budget
http://slidepdf.com/reader/full/11-balanced-diet-and-energy-budget 7/30
Overnutrition.
A form of malnutrition in which
nutrients are oversupplied
relative to the amounts requiredfor normal growth, development,
and metabolism.
Excess food is stored as fat
may result in obesity.
Resistance to disease e.g.:
CHD, hypertension.
Im balance diet - o v ernutrition
8/7/2019 11 - balanced diet and energy budget
http://slidepdf.com/reader/full/11-balanced-diet-and-energy-budget 8/30
UK s National guidelines for nutrition:
Clarify nutrients people need.
Clarify quantities of each nutrient.
However, actual values will differ between each individual:
different lifestyle, everyday activity, age.
G uidelines for nutrition
8/7/2019 11 - balanced diet and energy budget
http://slidepdf.com/reader/full/11-balanced-diet-and-energy-budget 9/30
Estimated population based on:
Committee on Medical Aspects of Food Policy (CO MA).
Replaced by Scientific Advisory Committee on Nutrition (SACN).
COMA develop dietary reference values (DRVs) show the range of
requirements and appropriate intakes for a group within the
population.
G uidelines for nutrition
8/7/2019 11 - balanced diet and energy budget
http://slidepdf.com/reader/full/11-balanced-diet-and-energy-budget 10/30
Dietary reference values (DRVs) consists of:
Lower reference nutrient intake (LRNI).
The amount of a nutrient that is enough for only the small number of
people who have low requirements (2.5%). The majority need more.
Estimated average requirement (EAR).
The average requirement for a particular nutrient for energy. For a
group of people receiving adequate amounts, the range of intakes willvary around the EAR.
G uidelines for nutrition
8/7/2019 11 - balanced diet and energy budget
http://slidepdf.com/reader/full/11-balanced-diet-and-energy-budget 11/30
Reference nutrient intake (RNI)
An estimate of the levels of protein, vitamins and minerals that should
meet the needs of most of the group to which they apply. The RNI is
the amount of a nutrient that is enough to ensure that the needs of nearly all the group (97.5%) are being met. By definition, many within
the group will need less.
G uidelines for nutrition
8/7/2019 11 - balanced diet and energy budget
http://slidepdf.com/reader/full/11-balanced-diet-and-energy-budget 12/30
Requirements of different nutrients will differ throughout life:
e.g.: women with heavy menstrual period need more iron than others.
e.g.: men ages 15-18 need more protein than women at the same age
as they still growing and making new tissues like muscles.
Balance between energy-giving nutrients and other nutrients are also
important as it can affect the chance to develop diseases.
G uidelines for nutrition
8/7/2019 11 - balanced diet and energy budget
http://slidepdf.com/reader/full/11-balanced-diet-and-energy-budget 13/30
Pearson page 49
G uidelines for nutrition
8/7/2019 11 - balanced diet and energy budget
http://slidepdf.com/reader/full/11-balanced-diet-and-energy-budget 14/30
How energy is measured?
M easure m ent of energy
8/7/2019 11 - balanced diet and energy budget
http://slidepdf.com/reader/full/11-balanced-diet-and-energy-budget 15/30
8/7/2019 11 - balanced diet and energy budget
http://slidepdf.com/reader/full/11-balanced-diet-and-energy-budget 16/30
In calorimeter:
A known quantity of food is burned in pure oxygen.
The energy released is transferred to the surrounding water as heat.
The rising temperature of surrounding water is measured.
The amount of food energy is calculated using the fact that 4 .2 kJ of
heat energy increase 1 oC of 1 kg of water.
M easure m ent of energy
8/7/2019 11 - balanced diet and energy budget
http://slidepdf.com/reader/full/11-balanced-diet-and-energy-budget 17/30
Amount of energy in each metabolic fuel:
Carbohydrate : 17.2 kJ/g.
Lipids : 38.5 kJ/g.
Proteins : 17.2 kJ/g.
SI unit of energy = kilocalories.
4 .2 kJ = 1 kilocalorie.
M easure m ent of energy
8/7/2019 11 - balanced diet and energy budget
http://slidepdf.com/reader/full/11-balanced-diet-and-energy-budget 18/30
Basal metabolic rate ( BMR):
The minimum calorific requirement (the amount of energy) needed to
sustain life in a resting individual.
BMR reflects the energy needed if the person lies on a bed all day andnight.
Calories are burned by bodily processes such as respiration, the
pumping of blood around the body and maintenance of body
temperature.
B asal m etabolic rate
8/7/2019 11 - balanced diet and energy budget
http://slidepdf.com/reader/full/11-balanced-diet-and-energy-budget 19/30
BMR is determined by various factors, as follows:
Genetics:
Some people are born with faster metabolisms; some with slower
metabolisms.
Gender:
Men have a greater muscle mass and a lower body fat percentage.
This means they have a higher basal metabolic rate.
Age:
BMR reduces with age. After 20 years, it drops about 2%/decade.
B asal m etabolic rate
8/7/2019 11 - balanced diet and energy budget
http://slidepdf.com/reader/full/11-balanced-diet-and-energy-budget 20/30
Weight.
The metabolic rate of obese women is 25% higher than the metabolic
rate of thin women.
Body fat percentage.
The lower your body fat percentage, the higher your BMR.
B asal m etabolic rate
8/7/2019 11 - balanced diet and energy budget
http://slidepdf.com/reader/full/11-balanced-diet-and-energy-budget 21/30
In normal circumstances, an individual s estimated average
requirement for energy (EAR) can be determined by multiplying the
BMR by the physical activity level (PAL).
If energy intake and requirements are the same = no weight lose orgain.
If energy intake and requirements are different = weight lose or
weight gain.
E sti m ated a v erage require m ent
8/7/2019 11 - balanced diet and energy budget
http://slidepdf.com/reader/full/11-balanced-diet-and-energy-budget 22/30
Pearson page 51
E sti m ated a v erage require m ent
8/7/2019 11 - balanced diet and energy budget
http://slidepdf.com/reader/full/11-balanced-diet-and-energy-budget 23/30
Quantification of the body to determined underweight , normal ,
overweight and obese can be done by using:
i) Body Mass Index.
ii) waist-to-hip-ratio.
M easure m ent of health
8/7/2019 11 - balanced diet and energy budget
http://slidepdf.com/reader/full/11-balanced-diet-and-energy-budget 24/30
Body Mass Index.
BMI = weight (kg) / height 2 (m).
Charts are different for adults and children.
BMI is a very limited tool as it does not consider the proportion of fat
and muscle in human body not a good predictor of CVDs.
B ody m ass index
8/7/2019 11 - balanced diet and energy budget
http://slidepdf.com/reader/full/11-balanced-diet-and-energy-budget 25/30
Classification of BMI:
B ody m ass index
8/7/2019 11 - balanced diet and energy budget
http://slidepdf.com/reader/full/11-balanced-diet-and-energy-budget 26/30
Underweight:
A person is considered underweight if his
or her BMI falls below 18.5 kg/m 2.
Underweight happened among people inthe developed countries may be due to
eating disorder (anorexia nervosa @
bulimia nervosa).
Lead to muscle wasting, heart
damage, amenorrhea, increase risk of
osteoporosis and complications
during pregnancy.
B ody m ass index
8/7/2019 11 - balanced diet and energy budget
http://slidepdf.com/reader/full/11-balanced-diet-and-energy-budget 27/30
Overweight:A person is considered overweight if his
or her BMI falls above 25 kg/m 2.
Most prevalent in people of develop
countries.
Overweight and obese could increase the
probability to develop various disease
CVDs, hypertension, diabetes.Most people who become overweight
consumed too many energy-rich items in
their diet as compared to their
requirements.
B ody m ass index
8/7/2019 11 - balanced diet and energy budget
http://slidepdf.com/reader/full/11-balanced-diet-and-energy-budget 28/30
However, in world population, the number of overweight people are
greater than the number who lack sufficient food.
B ody m ass index
8/7/2019 11 - balanced diet and energy budget
http://slidepdf.com/reader/full/11-balanced-diet-and-energy-budget 29/30
Pearson page 53
B ody m ass index
8/7/2019 11 - balanced diet and energy budget
http://slidepdf.com/reader/full/11-balanced-diet-and-energy-budget 30/30
Waist-to-hip-ratio.
Calculation of body shape.
More accurate indicator for CVDs than BMI.
Linked to the pattern of fat laid down in the body and the balance of
HDLs and LDLs in blood.
A ratio of over 0.8 in women and over 1.0 in men indicate an
increased risk of heart disease.
W aist-to-hip-ratio