Introduction to nutrition
A-Level/Advanced higher
Roy Ballam
Education Programme Manager
Georgine Leung
Nutrition Scientist
15th September 2010
© British Nutrition Foundation 2010
Overview
• A-level/Advanced Higher
• Nutrition – what is it?
• Energy and nutrients
• Why is what we eat important?
© British Nutrition Foundation 2010
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Nutrition research
The influence of diet on health is complex.
Although our understanding of the links between
diet and health has increased, there is still a
great deal to learn.
• Looking at eating habits and lifestyle
(epidemiology).
• Studying the effect of components in foods in
the body.
• Studying the effects of changing one
component of the diet on the health of
individuals or large groups (intervention studies).
• Dietary surveys (UK – National Diet and
Nutrition Survey, National Food Survey > Family
Food).
© British Nutrition Foundation 2010
Developing Nutritional Recommendations
Groups of scientists and other experts
asked to review research available.
Advice may then be given.
• Detailed consideration of the needs
of groups in the population, e.g. older
people, pregnant women, children.
• Effect of diet on illness, e.g. heart
disease, cancer.
• Estimates of the amount of energy
and nutrients required by different
groups – Dietary Reference Values.
© British Nutrition Foundation 2010
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Dietary Reference Values
Dietary Reference Values (DRVs) give
estimates of the amount of energy
and nutrients needed by different
groups of healthy people in the UK
population.
DRVs give several figures to cover the
needs of most people.
Estimated Average Requirement
(EAR)
Reference Nutrient Intake (RNI)
Lower Reference Nutrient Intake
(LRNI)
© British Nutrition Foundation 2010
Evidence
As part of your course …
• Food surveys
• National Diet and Nutrition Survey
• SACN
• Food Standards Agency
• Department of Health
http://www.defra.gov.uk/evidence/statistics/
foodfarm/food/familyfood/index.htm
http://www.sacn.gov.uk/index.html
http://www.food.gov.uk
http://www.dh.gov.uk/en/index.htm
http://www.nutrition.org.uk
© British Nutrition Foundation 2010
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Energy intake
Prot ein
15%
Carbohydrat e
50%
Prot ein
15%
Alcohol
2%
Fat
35%
Carbohydrat e
50%
Fat
33%
Estimated Average Requirements (EARs)
Source: Department of Health, 1991
© British Nutrition Foundation 2010
Macronutrients
The energy-providing nutrients.
Carbohydrate
Protein
Fat
(16kJ/g)
(17kJ/g)
(37kJ/g)
© British Nutrition Foundation 2010
Glucose
Amino acid
Triglyceride
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Carbohydrate provides energy.
Sugars
Complex carbohydrate
Intrinsic and extrinsic
Starch and dietary fibre (NSP)
The protein-sparing effect.
Diet low in carbohydrate
Increased
percentage of
dietary protein used
to provide glucose.
Less protein
available for the
growth and repair
of body tissues.
© British Nutrition Foundation 2010
What is the main source of carbohydrate
among British adults?
a. Potatoes and savoury snacks.
b. Sugar, preserve and confectionery.
c. Cereals and cereal products.
© British Nutrition Foundation 2010
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Protein is needed for growth, development and repair.
Animal protein: high biological value (HBV)
Plant protein: low biological value (LBV).
Protein complementation is where the amino acids of
one protein compensates for the limitations of another.
Isoleucine
Leucine
Lysine
Methionine
Phenylalanine
Tryptophan
Threonine
Valine
Rice and lentils
Beans and toast
© British Nutrition Foundation 2010
Fat provides energy, essential fatty acids, carries fat-soluble
vitamins, produces hormones and protects major organs.
• Saturated, mono- and poly-unsaturated fatty acids.
On average, how much
saturated fatty acids are we
eating in the adult British
population?
© British Nutrition Foundation 2010
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Micronutrients
300mg Ca in 240g
96.3mg is estimated to be absorbable
1.0 serving needed to equal 240g milk
Vitamins and minerals
Bioavailability and absorption
Calcium
Sources of calcium in the diet
Amount of calcium in food
Bioavailability of calcium in food
115mg Ca in 85g
5.9mg is estimated to be absorbable
9.5 servings needed to equal 240g milk
300mg Ca in 240g
96.3mg is absorbable
115mg Ca in 85g
5.9mg is estimated to be absorbable
16.3 servings needed to equal 240g milk
Source: Theobald (2005) Dietary calcium and health
© British Nutrition Foundation 2010
Vitamin & mineral intakes: % below LRNI
% British males below LRNI
Age (years)
<4
4-6
7 - 10
11 - 14
15 - 18
19 - 34
35 - 64
65+
Riboflavin
0
0
4
6
6
7
1
2
Vitamin B6
4
4
7
1
1
0
1
1
Vitamin B12
0
0
0
0
0
1
0
0
Folate
0
0
0
1
0
2
0
0
Vitamin A
0
3
3
8
13
16
5
3
Iron
3
3
3
3
3
1
1
1
Calcium
2
3
3
13
9
2
2
2
Magnesium
4
3
2
28
11
9
7
8
© British Nutrition Foundation 2010
Source: National Diet and Nutrition Survey 2003
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Vitamin & mineral intakes: % below LRNI
% British females below LRNI
Age (years)
<4
4-6
7 - 10
11 - 14
15 - 18
19 - 34
35 - 64
65+
Riboflavin
0
0
1
22
21
12
5
9
Vitamin B6
1
5
0
1
5
7
1
2
Vitamin B12
0
0
1
1
2
1
1
1
Folate
0
1
2
3
4
3
2
5
Vitamin A
8
7
9
20
12
13
5
3
Iron
16
4
3
44
48
40
23
5
Calcium
1
2
5
24
19
7
5
9
Magnesium
0
2
5
51
53
21
9
23
Which mineral is of greatest concern with the <4 age
group in British females?
© British Nutrition Foundation 2010
Source: National Diet and Nutrition Survey 2003
Dietary fibre (NSP)
•A type of carbohydrate found almost exclusively in
plants.
Insoluble dietary fibre
Soluble dietary fibre
Improves gut health by absorbing water in
the colon, increasing stool bulk and
stimulating peristalsis.
Helps reduce cholesterol in the blood by
reducing low density lipoprotein (LDL).
•Some metabolism occurs in the large bowel
providing 8.4kJ per gram.
© British Nutrition Foundation 2010
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Water
Water is provided by both food (20%)
and drinks (80%), except for stronger
alcoholic drinks.
Drink
Loss of
water in
urine
(ml)
Net gain
of water
(ml)
Lager
568ml
(1 pint)
170
398
Spirits
25ml
(single)
100
-75
Requirements vary.
Source: Benelam & Wyness (2010) Hydration and health
© British Nutrition Foundation 2010
http://onlinelibrary.wiley.com/doi/10.1111/j.14673010.2009.01795.x/abstract
www.nutrition.org.uk/nutritioninthenews/hydration/
Why is what we eat important?
• Overweight and obesity.
• Cardiovascular disease.
• Diabetes.
Future eSeminars
• Cancer.
To cover diet related diseases and
other topics.
Coming soon: 5th October
• Bone and joint health.
Satiety
• Nutrient deficiencies.
What’s your beef? Red meat in the
diet
© British Nutrition Foundation 2010
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For further information, go to:
www.nutrition.org.uk
www.foodafactoflife.org.uk
BNF is grateful for financial support from
the Agricultural and Horticultural Development Board
to enable us to host these eSeminars.
© British Nutrition Foundation 2010
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