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TOPIC D1: HUMAN NUTRITION
1. Definitions – nutrients, essential nutrients, vitamins and minerals
2. Fat in the diet
3. Protein in the diet
4. Malnutrition – starvation
5. Malnutrition – obesity
6. Appetite control
BIG IDEAS AND BIG QUESTIONS

What are some of the key nutrition-related health threats that the world faces today?

In what ways can we help people to make healthy, sustainable choices?

What do YOU want to learn about human nutrition and health?
GENERAL RESOURCES
GLOBAL NUTRITION AND MALNUTRITION

The World Food Programme Global hunger map: http://cdn.wfp.org/hungermap/

The World Food Programme Hunger centre: http://www.wfp.org/hunger
NUTRITION RESOURCES

The Harvard Nutrition centre: http://www.hsph.harvard.edu/nutritionsource/

The US Government Nutrition Resource Centre: http://www.nutrition.gov

The UK Nutrition Foundation:http://www.nutrition.org.uk
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WHAT DO YOU NEED TO EAT?
You should already have learned this in your PE nutrition course, but if you need reminding,
take a look at the healthy eating pyramid/plate for the classic recommendations. (Note
that different types of plate/ pyramid are produced for different cultures (European, Indian,
South Asian, Caribbean etc):
http://www.hsph.harvard.edu/nutritionsource/pyramid/
UNDERSTANDINGS
D.U.1: Essential nutrients cannot be synthesized by the body, therefore they have to be
included in the diet
ESSENTIAL DEFINITIONS
1. Define nutrient:
2. What is the difference between an essential nutrient and a non-essential nutrient?
3. List the essential amino acids:
4. List essential fatty acids
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D.1.U.2: Dietary minerals are essential chemical elements
D.1.U.3: Vitamins are chemically diverse carbon compounds that cannot be synthesized
by the body
D.1.A.1: Production of ascorbic acid (Vitamin C) by some mammals, but not others that
need a dietary supply
TOK: There are positive effects of exposure to sun such as production of vitamin D, as
well as health risks associated with exposure to UV rays. How can conflicting knowledge
claims be balanced?
VITAMINS AND MINERALS
1. What is the definition of a vitamin? Give 4 examples
2. . What is the definition of a dietary mineral? Give 4 examples
VITAMIN C (Ascorbic acid)
Additional Resources:

The
Linus
Pauling
Micronutrient
Centre:
http://lpi.oregonstate.edu/infocenter/vitamins/vitaminC/

A quick review of the link between Vitamin C and the common cold – can Vitamin C
megadoses help to prevent a cold?: http://www.bbc.co.uk/programmes/p00ll1yh

The
WHO
definitive
guide
to
Vitamin
C:
http://helid.digicollection.org/en/d/Js2901e/6.1.html
3. What does Vitamin C do in the animal body?
4. List foods high in Vitamin C
5. What are the effects of Vitamin C deficiency?
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6. What is scurvy? Whom does it affect?
7. What is the recommended daily allowance (RDA) of Vitamin C in adults in:

The USA

Switzerland

Russia

The UK

Australia
8. According to the US, what is the minimal RDA (required to prevent scurvy) in adults?
9. Is the recommended RDA for Vitamin C the same for all ages and types of people?
10. How have animal studies been used to determine the RDA of Vitamin C in humans?
How valid do you think the levels calculated in animals are to humans?
Does scurvy affect animals other than humans?
VITAMIN D
10. What does Vitamin D do in the body?
11. What are the sources of Vitamin D (in the diet and elsewhere)?
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12. EVALUATE the risks of Vitamin D deficiency against the risks of sunburn and skin
cancer…
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D.1.U.6: Malnutrition may be caused by a deficiency, imbalance or excess of nutrients in
the diet
D.1.U.9: Starvation can lead to breakdown of body tissue
MACRONUTRIENTS
Carbohydrates
Proteins
Fats
Since all macronutrients contain energy, high intake can lead to storage of excess energy
as fat, therefore weight gain, possible obesity and coronary heart disease. The ideal is a
balance of all three to ensure sufficient intake of all essential nutrients.
Disadvantages



1. Native Inuits traditionally consume a high-far high-protein diet based on whale meat
and fish. Why does their diet result in a lower risk of heart disease, stroke and
atherosclerosis compared to a western high –fat diet?
Watch Hank’s analysis of High-fructose corn syrup.
2. List 4 ‘PROS and 4 ‘CONS of HFCS
1.
2.
3.
4.
DIETARY FAT
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D.1.U.5: Some fatty acids and some amino acids are essential
Resources:



Shining the spotlight on trans fats (from Harvard Pubic Health department)
Learning about the link between fat intake and disease: the good, the bad, and the
downright untrue
a 5 minute podcast from the Cochrane Review site, reviewing the current state of
knowledge about heart disease and dietary fat
You need to understand, and be able to define:

essential fatty acids

The three main sections of a fatty acid: carboxyl, hydrocarbon, and methyl group

Which end of the fatty acid is the omega (ϖ) end?
1. Annotate the fatty acids below to identify these regions specified above:
2.
What is the difference between a saturated and an unsaturated fat?
In unsaturated fats, how does the position of the ‘missing hydrogen atoms’ around the
double bond affect the chemical properties (and health effects) of the fatty acid?
3.Explain the process of hydrogenation.
Which types of fat are produced by
hydrogenation?
4. Are there any naturally occurring examples of trans fats?
5. List examples of the following:
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Type of fat
Examples
Polyunsaturated: cis
Polyunsaturated: trans
Monounsaturated
Saturated: animal
Saturated: plant
6. Omega-3 and Omega – 6 are naturally occurring cis-polyunsaturated fatty acids.

What are the natural sources of these fatty acids?

What are their supposed health benefits?

Are there potential adverse effects of omega -3 and omega-6 fats?
7. Explain briefly the link between a high-fat diet and heart disease
8. Which types of fat carry the highest risk of predisposing to heart disease?
PHENYLKETONURIA
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D.1.U.5: Some fatty acids and some amino acids are essential
D.1.A.2: Cause and treatment of phenylketonuria
Watch these short interviews with two 18 year-olds (Jack and Claire) for a ‘personal
introduction’ to life with PKU:
http://www.open.edu/openlearn/body-mind/social-care/phenylketonuria-long-termcondition
Resources: Use these links to help you:

PKU from Utah Genetics:

http://learn.genetics.utah.edu/content/disorders/whataregd/pku/

Learning about PKU from the US Genome Website:

http://www.genome.gov/25020037

The national PKU alliance: http://www.npkua.org/index.php
1. Explain the cause and consequences of PKU:
2. Explain how PKU is treated (managed):
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MALNUTRITION
D.1.U.6: Malnutrition may be caused by a deficiency, imbalance or excess of nutrients in
Watch this 2 minute video from the WFP:
http://www.wfp.org/videos/nutrition-2-minutes-0
Use the WFP hunger site to help you explore and investigate the differences between
hunger and malnutrition: http://www.wfp.org/hunger
1. What is the definition of malnutrition?
PROTEIN MALNUTRITION
2. What is the name for the disease associated with general protein malnutrition?
3. What is the origin of this name?
4. What are the key consequences of general protein deficiency malnutrition?
5. Which countries have the highest incidence of protein deficiency malnutrition?
6. Can over-consumption of protein cause protein malnutrition? – explain HOW, and
outline the potential consequences of protein over-consumption.
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STARVATION II: ANOREXIA NERVOSA
D.1.U.9: Starvation can lead to breakdown of body tissue
1. Define anorexia nervosa: When was the disease first identified?
2. Compare the incidence of anorexia nervosa in males and females
3. . Outline the adverse health effects of anorexia nervosa
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OBESITY
D.1.U.8: Overweight individuals are more likely to suffer hypertension and type II
diabetes
Resources:
Hank on obesity
BBC: Obesity is NOT a problem for the rich
BBC 2014: Obesity quadruples to 1 billion in the developing world
1. Define obesity:
2. Which countries have the highest obesity rates in the world?
Watch Hank on Obesity:
3. Hank outlines 8 reasons for the obesity epidemic in the US. List the reasons he
outlines:
1.
2.
3.
4.
5.
6.
7.
8.
4. Hank outlines a 5-step prescription for weight loss. Outline his prescription:
1.
2.
3.
4.
5.
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5. Outline and evaluate the reasons for increasing rates of clinical obesity in certain
countries. (Food availability, ability to cook, pre-packaged food, portion sizes,
transportation, sedentary lifestyles, poverty, genetic factors)
6. Outline diseases associated with obesity
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APPETITE CONTROL
D.1.U.7: Appetite is controlled by a centre in the hypothalamus
RESOURCES:
‘The Anatomy of Appetite’ From the Wellcome Trust
Watch the Wellcome Trust video on appetite control:
Questions are based on the video:
Appetite is complex: it involves the BRAIN, the STOMACH and INTESTINES, the
PANCREAS and ADIPOSE TISSUE and also OUR ENVIRONMENT
Outline the role in appetite control of:
a) The hypothalamus:
b) Ghrelin:
c)
PYY366 (and CCK):
d) Leptin (Greek for ‘thin’)
e) Insulin (and glucagon):
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DIETARY FIBRE
D.2.U7: Materials not absorbed are egested (Oxford Biology Course Companion page 676).
 Define dietary fibre.
 State two examples of dietary fibre.
 Define egestion.
 List materials that are egested from the body
Resource:
Fibre:
Start
roughing
it
–
the
full
story:
from
Harvard
Public
Health:
http://www.hsph.harvard.edu/nutritionsource/fiber-full-story/
1. What is the definition of dietary fibre?
2. What are the sources of dietary fibre?
3. What is the recommended quantity (in g) of fibre for males and females of your age?
4. What are the health benefits of a high fibre diet?
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NOW OFF SYLLABUS BUT FUN
DIET, SOCIETY AND HEART DISEASE: A TRIP AROUND THE WORLD
Resources:
The Maasai ‘paradox’:

http://sciencenordic.com/maasai-keep-healthy-despite-high-fat-diet

http://www.sciencedaily.com/releases/2008/07/080718075357.htm

http://www.empiricalzeal.com/2012/09/30/milk-meat-and-blood-how-diet-drivesnatural-selection-in-the-maasai/
The Inuit ‘paradox’: http://www.theiflife.com/the-inuit-paradox-high-fat-lower-heartdisease-and-cancer/
The Mediterranean diet:
http://www.nytimes.com/2013/02/26/health/mediterranean-diet-can-cut-heart-diseasestudy-finds.html?pagewanted=all&_r=0
The
unhealthy
‘Western’
diet:
Heart
disease
in
Scotland
(a
world
leader!):http://www.hriuk.org/about-heart-disease/Scotland/
And just to throw a spanner in the works: this link looks at all sorts of inconsistencies
between diet and heart disease in Europe:
http://www.dietdoctor.com/stunning-saturated-fat-and-the-european-paradox
Compare and contrast the diets and the health of the different human populations
(societies) listed above, with particular attention to their dietary fat intake. Is dietary fat
intake (type and quantity) the only (or the key) determinant of risk for heart disease?
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