What is the nutritional value of chocolate?

advertisement
Health experts
You are totally dedicated to making sure
that our nation stays healthy. Your mission
is to persuade people that eating chocolate
is harmful to their health and they should
stop eating it now!
To accomplish your mission you need to answer these questions:
1.What is the nutritional value of chocolate? (What ingredients are in different
sorts of chocolate and what do they each add to our diet?)
2.Chocolate is high in sugar. What are the problems of eating too much sugar?
3.Chocolate is high in fat. What are the problems of eating too much fat?
4.How much chocolate do we eat in Britain? (Compare this with the past and with
other countries.)
Then you need to do this:
•
Use the evidence you have found in answering those questions to put together a
convincing argument to persuade the British people to stop eating chocolate!
Where can you find information?:
Your group has access to an information pack and a computer so that you can do
extended research. You will also have access to atlases.
Lower School Information Pack
1.What is the nutritional value of chocolate?
What ingredients are in different sorts of chocolate?
Cocoa beans roasting
Making cocoa liquor
cocoa butter
What are the ingredients in chocolate and how is it made?
sugar
Cocoa beans are roasted and ground up very finely to make cocoa liquor. This smooth, liquid paste
contains about 50% cocoa butter (a sort of fat). Cocoa Liquor is one of the ingredients in both plain
and milk chocolate. Chocolate recipes are all different but there are three main types:Dark Chocolate - contains about 35% cocoa liquor, 35% cocoa butter, 29% sugar and 1% other
ingredients such as Lethicin (an emulsifier) and Vanilla.
Milk Chocolate - contains about 10% cocoa liquor, 30% cocoa butter, 20% milk powder and 38% sugar
and 2% other ingredients such as Lethicin (an emulsifier) and Vanilla.
‘White chocolate’ - contains no cocoa liquor. It has about 32% cocoa butter and 18% milk powder,
49% sugar and 1% other ingredients such as Lethicin (an emulsifier) and Vanilla.
Mixing cocoa
liquor, cocoa
butter and sugar
(and sometimes
milk) to make
chocolate.
Lower School Information Pack
You could: show on a
diagram or pie chart how
much cocoa liquor, milk and
other ingredients (sugar and
cocoa butter) go into
different sorts of
chocolate.
1.What is the nutritional value of chocolate? What do the ingredients
add to our diet?
Nutritional content of dark, milk and white chocolate (100g bar)
DARK
Chocolate
MILK
Chocolate
WHITE
Chocolate
3g
8g
8g
Fats
34g
32 g
37g
Carbohydrate (mostly
sugar in chocolate)
60g
57g
52g
3g
3g
3g
2080
2160
2260
Component
Protein
Other
Energy (kJ)
Your body
uses protein
for growth
and repair
Your body
uses fat and
sugar for
energy
Most of this will
be sugar.
Nutritional value.
‘Nutrition’ is in food. Some foods are more valuable (useful to help your body stay healthy) than others.
Your body needs all sorts of things to stay healthy.
It needs fibre to keep your digestive system healthy. There is no fibre in chocolate.
It needs protein to make and replace the cells in your body. Your body is made of lots of different proteins. You
need about 50g of protein each day. How much protein is in chocolate?
It needs some sugars (about 90g each day) and starches for energy to stay warm and move about. It needs some
fats (about 70g fat each day) for energy to stay warm and move about and also to make some cells in your body
e.g. nerve cells and fat storage cells. How much sugar and fat is in chocolate?
Sugar and fat can give you lots of energy (calories) but, if you eat too much energy (calories), you will get fat.
Men need about 2500 Calories each day; women about 2000.
Your body also needs small amounts of many different sorts of vitamins and minerals to stay healthy.
You need to be able to tell people about the nutrients in chocolate.
Is there too much of some nutrients? Too little of others?
Lower school information pack
2 - Chocolate is high in sugar. What are the problems of eating too much sugar?
•
•
•
•
•
•
Chocolate is high in sugar.
Sugar contains lots of calories (energy).
Sugar does NOT contain any other important nutrients.
It has no health benefit except to provide energy.
Many people in Britain eat more calories than they need.
If you eat a diet high in calories, you have to do masses of
exercise to use up the extra energy or you will definitely
gain weight.
Obesity – when people are very fat, they are
said to be obese.
•
•
•
•
•
•
In Britain, 1/4 (25%) of adults are obese
and 1/5 (20%) of children aged 10-11 are
obese.
Sugar is a big contributor to a high calorie
diet.
People can get addicted to the sweet
taste of sugar. Sugar causes the brain to
produce dopamine in the reward centre of
our brain. This makes us feel good and it
is why we can become addicted to sugary
foods.
If you are addicted to something, it is
very hard to stop taking it.
Sugar does not make us feel full and
satisfied when we eat it. So people can
eats lots sugar without feeling full.
Sugar is included in many foods, even
some that we think are ‘good for us’ such
as fruit juice and yoghurt.
Why doesn’t sugar make us feel full?
•
Starchy foods such as bread and
potatoes contain starch.
•
Starch is a big particle made of lots of
chains of a sugar called glucose.
•
Starch makes us feel full. The glucose in
starch helps us to feel full because it
lowers our ‘hunger hormone’, ghrelin.
•
Eating too much
sugar will make
you fat!
•
•
The sugar in chocolate is called sucrose.
This is a much smaller particle made out
of glucose and fructose.
Fructose does not lower the hunger
hormone, so we can eat lots of sucrose
and fructose without feeling full.
This encourages us to over eat and get
fat.
2 - Chocolate is high in sugar. What are the problems of eating too much sugar?
Eating too much sugar can make your teeth go bad
•
•
•
•
•
•
•
•
•
•
•
•
•
Sugar is strongly linked with tooth decay.
When we eat sugary foods the bacteria in our mouths thrive
using the energy from the sugar to grow and reproduce.
The bacteria produce acid which breaks down the enamel on
our teeth and rots them.
In 2012 some UK research found out that one quarter (25%)
of five year olds had some tooth decay.
Sugary food and drink should only be drunk at meal times to
reduce the risk of tooth decay but 66% of chocolate is eaten
between meals!
Too much sugar can contribute to Type 2 diabetes.
Insulin is a hormone which tells our cells to break down and digest
sugar.
When we eat too much sugar our bodies can become ‘insulin
resistant’ which stops our body breaking down sugar efficiently.
Our blood can become very high in sugar which is not good for us.
The more ‘insulin resistant’ our cells become, the more our body
tries to produce insulin to cope with the excess sugar in our blood
When our body can no longer cope with the extra sugar in our
blood we can develop a condition known as Type 2 Diabetes.
In the UK today type 2 Diabetes is massively increasing.
The increase in Type 2 diabetes is due to more people eating too
much fat and sugar and getting too fat.
In England 3.1 million people over 16 are affected by diabetes and
this figure is steadily rising.
3 - Chocolate is high in fat. What are the problems of eating too much fat?
•
•
•
•
There are 2 main types of fat: saturated
fat and unsaturated fat.
Saturated fat is the least healthy. It has
been linked with many health problems.
Chocolate is rich in saturated fat!
It is rich in the fat our bodies use to make
cholesterol.
If someone has a heart
attack or a stroke you must
Dial 999 for an ambulance.
What are the dangers of having high amounts of cholesterol in
our bodies?
•
Cholesterol is a fat which circulates in the blood and coats
the inside of our artery walls. Arteries are the tubes along
which our blood flows.
•
If cholesterol coats the inside of our arteries it makes the
artery narrower. This restricts the flow of blood. In the
worst cases a build up of cholesterol can block the artery.
•
All the organs and cell of your body need a good supply of
blood. When blood does not flow freely the cells do not get
enough oxygen and they can die.
•
If you have a blood clot in your heart, this is called a heart
attack.
Stroke is serious
If you have a blood clot in your brain, this is called a stroke.
As different parts of your brain control different parts of your body, the
symptoms depend on the part of the brain affected and how bad the damage is.
Symptoms begin suddenly. The face may drop on one side, the person may not be
able to smile or their mouth or eye may droop. The person with a stroke may not be
able to lift their arms. Their speech may be slurred, or they might not be able to
talk at all.
Other symptoms might include:
• paralysis of one side of the body
• sudden loss or blurring of vision
• dizziness
• confusion
• problems with balance and co-ordination
• a sudden and blinding headache worse than anything experienced before
• unconsciousness
3 - Chocolate is high in fat. What are the problems of eating too much fat?
•
•
•
•
•
•
•
•
•
•
Chocolate is very high in fat and fat is
very high in Calories (energy).
Fat contains 9 Calories per gram.
Protein and carbohydrate both contain
only 4 Calories per gram.
Fat is the most energy dense of all
foods.
School age children need between 1600 and
2000 Calories (energy) each day.
Chocolate is very high in Calories.
A small 50g bar of chocolate contains more
than 250 Calories
A 100g bar of milk chocolate contains more
than 500 Calories.
Even a small bar of chocolate uses up lots of
our daily Calorie allowance. By eating
chocolate regularly we risk eating far too
many Calories and gaining weight .
In UK 1 in 5 10 – 11 year old are obese (very
overweight).
Obesity – what are the health risks?
Obesity is being very overweight.
The number of people with obesity in the UK has more than
trebled since 1990. Doctors are very worried. Why?
Being very overweight (obese) is linked with many health
problems, including:
•
Diabetes
•
Heart disease •
High blood pressure – this increases the chance of having a
stroke or heart attack
•
Arthritis – a painful condition of the joints
•
Some cancers (e.g. breast cancer, prostate cancer)
•
Snoring and stopping breathing during sleep
•
Stress, anxiety, and depression
•
Infertility – being unable to have babies
•
Gallstones
Obesity could be responsible
for even more ill health than
smoking!
You need to persuade people to eat less chocolate for their health!
You could: work out the percentage of our daily calories that a 100g bar of chocolate uses up.
You could: find out more about some of the diseases that obesity can cause.
4 - How much chocolate do we eat in Britain?
Compare this with how much is eaten in other countries
Country
Amount of Chocolate
(Kg) consumed per
head of population
per year
% of population
considered obese
(obese means
very fat)
United
Kingdom
10
23
Belgium
10
12
Austria
7
9
Italy
2.75
8.5
Australia
5.5
22
USA
5
31
Canada
3
14
Brazil
1.38
--
Japan
1.82
3.2
China
0.12
--
It’s important to remember that these number are averages.
Not everyone in a country will eat the same amount of chocolate.
Some will eat an awful lot and others will eat very little.
Health experts
You could use this data to make a graph
•
•
Can you see any patterns?
Is there a link between how much
chocolate people eat and how obese
(fat) people in that country are?
More information
The average person in Britain eats around 10
kilograms of chocolate each a year…
• That’s about 180 bars of chocolate.
• Britain guzzles 50 Kit-Kats every second!
• People in Britain spend £3 billion on chocolate
based confectionery.
Many European countries (but not all) eat a lot of
chocolate: e.g. 12 kg eaten per person in Ireland,
4.5 kg in France but only 1 kg in Poland.
Europe ate 2.5 million tons of chocolate products
in 2007. That’s about half the chocolate eaten
world-wide.
In countries like Japan and China, they eat far
less chocolate. The people there are not as fat as
Europeans.
Although Americans have a very high number of
really fat people, the population as a whole eats
half the amount of chocolate that British people
eat.
Lower school information pack
4 - How much chocolate do we eat in Britain?
How has the amount of chocolate we eat changed over time?
Aztec god of
chocolate
Before the 16th century, no one in Europe ever ate or drank chocolate. It
came from Central America, where the Incas, Aztecs and Mayans lived.
They mixed ground cacao seeds with seasonings to make a spicy, frothy
drink called chocolatl, meaning ‘warm liquid’. In 1519, Emperor Montezuma,
served chocolatl to his Spanish guests (the European explorer Hernando
Cortez and his men) in golden goblets. Montezuma's chocolatl was very
bitter, and the Spanish did not like the taste. They added sugar to sweeten
the Aztec Chocolate. Cortez brought cocoa beans to Spain in 1528 and the
fashion for drinking chocolate gradually spread through Europe.
Until 1800 or so, it was only ever taken as a drink.
• In 1847 Fry and Son in France made the first chocolate bar.
• In 1875 Nestle, a Swiss company, added milk to their chocolate and made the first milk
chocolate.
• In 1905 Cadbury launched their first milk chocolate bar and called it Dairy Milk.
• The popularity of chocolate grew and grew as chocolate became less expensive.
World War 2
• From 1939 to 1945, there was a terrible war (World War 2).
• Food was rationed during the war. Rationing for sweets and
chocolate started in July 1942.
• Each British person was allowed 200g of either sweets OR
chocolate each month during the war.
• Because of the war, chocolate makers could not get the raw
materials they needed to make chocolate (cocoa beans, sugar and
fresh milk) so they made far less.
• Cadbury introduced a special Ration Chocolate which was made
from skimmed milk.
• During the war chocolate consumption was very low indeed.
• Chocolate rationing only ended in 1953.
Early European chocolate drinkers
A bar of
Edwardian
chocolate
Chocolate rationing ended in 1953.
After that, there was a rapid
increase in the amount of chocolate
eaten in the UK.
People in Britain now eat, on
average, about 10kg of chocolate
per person per year.
Advertising:
In the 1970s there was a huge
growth in the sale of chocolate due
to some very clever advertising on
TV.
You could: find out more about how
people have been persuaded to eat
more chocolate through advertising.
You could: work out how much chocolate per year a British person was allowed to eat during war rationing and compare it with
how much we eat now and with how much chocolate we ate before 1800.
Download