• Ilove eating fast foods but why does my mom say it is not good for me?
  • Why must I eat my vegetables if I just want to eat protein, bread and pasta?
  • Can I get sick if I do not eat the right foods or not enough of a certain type of food?

Abalanced diet

Now we know that there are different foods that are classified into the four food groups. The next step is to see what amounts of each food group we need to eat regularly to stay healthy. This is called a balanced diet. What is a diet?

Discuss the word 'diet' with your class and come up with a definition for this word. Write it below.

For nutritional scientists (people who study the effects of diet on health and well-being), the word 'diet' means the sort of food that people regularly eat. When we say we eat a healthy balanced diet we mean that we eat food that contains adequate or the right amounts of all the nutrients our body needs to function.

Food pyramids

A food pyramid provides a guide to a healthy balanced diet. It shows how to classify food types into different levels. A balanced healthy diet will include servings from each level of the food pyramid and will show the correct quantities you need to eat:

  • You need to eat a little of the food at the top (oils, sweets, etc.)
  • The food in the middle of the pyramid, fruit and vegetables, must also be eaten in fair amounts.
  • You should eat less meat, chicken, fish and other proteins than vegetables and fruit.
  • You need to eat more of the food at the bottom of the pyramid (breads, pastas, rices, etc.).

Here is an example of a food pyramid:

A food pyramid

Some people eat a very unhealthy diet and turn the food pyramid upside down! They eat far more sweets, cakes, fatty rich food and far less vegetables and starches!

Mmm...I think I have a very balanced diet and I love being healthy! But I am not so sure about my brother. I kept a record of what he ate for a week.

Evaluating a diet to see if it contains all the food groups.


  • arecord of the weekly diet of Farrah's brother, Rajesh


  1. Carefully study Rajesh's weekly diet.
  2. Answer the questions that follow.





toast with peanut butter, coffee with milk and 3 teaspoons of sugar

two-minute noodles, cream soda, jelly (while watching TV)

spaghetti bolognese (with chopped carrots in the mince) with cheese sprinkled on top, fruit juice, tea with milk and 2 teaspoons of sugar


toast with peanut butter, coffee with milk and 3 teaspoons of sugar

two-minute noodles, Coke, toast with peanut butter, popcorn (while watching TV)

Mom and Dad worked late - scrambled egg on toast with baked beans; coffee with milk and 3 teaspoons of sugar


late for school - didn't eat.

2eggs and toast with cheese, tea with milk and 3 sugars, more toast with jam and peanut butter later (while watching TV)

Hawaiian pizza, coke, cream soda, chocolate milkshake


toast with peanut butter, coffee with milk and 3 teaspoons of sugars

indoor hockey practice after school - pie from tuckshop and Coke, chocolate and packet of hot chips

roast chicken, butternut, baked potatoes, salad, fruit juice, coffee with milk and 1 teaspoon of sugar


toast with butter (peanut butter is finished), coffee with milk and 3 teaspoons of sugar

band practice after school - pie and coke from tuckshop, sweets

takeaway chicken in a bucket, hot chips, Coke, tea with milk and 3 teaspoons of sugar, popcorn


Reading only this table showing Rajesh's weekly diet, do you think he has a balanced diet? Why do you think so?

Assess the learner's capability to make conclusions from the data presented. Rajesh does not have a balanced diet for a few reasons. He consumes a lot of sugar, oil and fat in the sweets, Coke, takeaways and sugar in his drinks. He also has a lot of starch, but not much fresh fruit and vegetables.

Now let's use our knowledge of a food pyramid to see how healthy Rajesh's diet for the week was. Use the tallying method to keep score of everything he ate: to tally up results you make one line down for every item you count and when you get to the fifth item you draw a diagonal line through the other four. That makes it easy to count in fives and count the few left over at the end.

Total Fats and Oils

Total Proteins

Total Vitamins and Minerals

Total Carbohydrates

List the times and days when Rajesh ate fruit or vegetables.

On Monday, Rajesh had carrots in the spaghetti bolognaise and on Thursday he had salad and butternut with his meal.

What important food group is Rajesh missing from his diet if he does not eat enough fruit and vegetables?

He will not be getting enough vitamins and minerals.

Can you predict what will happen if Rajesh continues with this diet?

If he is not already very overweight he soon will be overweight and may develop problems that accompany this - diabetes, bad skin, aching joints, greater risk of heart disease etc.

Now that you have tallied up the different food groups that Rajesh ate in a week, do you think he ate a balanced diet? Why do you say so?

Rajesh's diet was not balanced because Rajesh did not eat the correct quantities of food from the different food groups and therefore I don't think their diet is very balanced.

Do you think Rajesh is a very active person? Why do you say so?

He lies in front of the TV most afternoons, and his only extramural activity is band practice, which is not very energetic. Indoor hockey once a week is probably not enough exercise.

Takeaways are known for being fatty and oily because restaurants often prepare the food in deep oil. Rajesh and Farrah's family ate takeaways twice in the week and the mom cooked twice. Compare the cooked meals with the takeaways specifically focusing on the amount of oil used to prepare the meals.

The bolognese and the roast chicken were probably prepared at home and the pizza and 'bucket' chicken were probably takeaways. The roast chicken meal included a lot of vegetables and the bolognese included carrots in the mince as is the tradition in many homes. These meals are far healthier than the oily chicken or pizza that they had because they contain fewer oils and more vegetables.

What advice would you tell Farrah to give to her brother?

Learners should include something about eating a more balanced diet, which would include eating more fresh fruit and vegetables and less fats, sugars and oils. Rajesh should cut down on the amount of sugar he puts in his hot drinks, he should always eat breakfast in the morning, he should not rush when he eats his meals and just buy food from a tuck shop. Rajesh should also become more active and not just lie in front of the TV for the afternoon. Farrah and her brother Rajesh should also consider talking to their parents about the meals they are given in the evening. They should not have takeaways so often and the parents should also take responsibility for what their children eat.

Now that you have completed this activity, explain why different portions of the different food groups are necessary for a balanced diet?

Comparing meals


  1. Below are photographs of different meals for breakfast, lunch and dinner.
  2. One of the meals is unhealthy and the other meal is healthy.
  3. Choose which is the healthier option and write a paragraph explaining why. List the food groups that are missing from the unhealthy option compared to the food groups that are present in the healthy option.


Option 1: Fruit loops

Option 2: Fruit salad

The fruit salad is healthier as it contains a variety of fresh fruit which will satisfy some of your daily requirement of fruit and vegetables. The fruit loops are unhealthy as they contain a lot of sugars, colourants and flavourants. They do not have any nutritional value.

Option 1: Oats with raspberries

Option 2: Flapjacks with syrup

The oats with raspberries is more healthy compared to the flapjacks with syrup. Oats is a good source of nutrition and the raspberries are very high in vitamins. The flapjacks are unhealthy for breakfast as they contain a lot of fats and sugar.


Option 1: Egg salad

Option 2: Fried chips

The egg salad is the healthy option. This meal contains a variety of food groups as there are fruits and vegetables containing vitamins and minerals and the eggs are a good source of protein. The fried chips are very unhealthy as a meal as this only consists of one food group (starch) and there is added oil from the frying.

Option 1: Hamburger

Option 2: Omelette with salad

The omelette is the healthy option. As with the egg salad, this meal contains fresh salad and the eggs are a source of protein. the omelette possibly has meat or mushrooms and cheese which also adds to the nutritional content. Although the hamburger contains meat, starch and cheese, it was probably prepared in an unhealthy way. Consider that the meat was fried in oil and that the bread has less nutritional value than vegetable starches. This meal also lacks fresh fruit or vegetables.


Option 1: Chicken pieces

Option 2: Beef, peas and rice

The beef, peas and rice is the healthy option for supper as the meal contains starch (rice), meat for protein (beef) as well as vegetables (peas). The other meal is unhealthy as it only contains one food group, namely protein from the chicken pieces.

Diseases caused by an unhealthy diet

There are many people in the world that do not or are not able to eat a healthy, balanced diet. Many choose to eat an unhealthy diet while others do not have a choice.

Many people live in cities and can afford to buy takeaways often, or to eat hastily prepared meals that do not always include foods from the 4 food groups.

Remember the food pyramid we saw before? Below is a picture of the food pyramid of someone with an unhealthy diet.

The food pyramid of an unhealthy person's diet.

Discuss in your class why you think this kind of food pyramid is unhealthy. Compare it to the healthy food pyramid and write down some of the differences below.

This food pyramid is out of proportion compared to the previous one and does not form the shape of a pyramid anymore. This is because the person eats a lot more fats and oils compared to how much they should eat in a healthy diet. The amounts of meat and dairy products are about the same. But, there is a lack of fruit and vegetables in the diet. This is very unhealthy as the person will not be getting enough vitamins and minerals in their diet.

Some families have to eat what they can afford. They do not have the privilege of choosing what their food pyramid looks like but eat what they can buy with their small incomes. This would mostly consist of carbohydrates and some vegetables, and rarely includes meat and enough proteins and other vitamins.

Let's look at the causes of a poor, unhealthy diet and then at possible diseases that may arise from this.

Causes of a poor diet

There are many causes of a poor diet.

  1. Diseases and infections: When someone has a chronic illness, such as HIV/AIDS, they are sick for a very long time. Their bodies become weak and they cannot take in nourishment from the food they manage to eat, resulting in a poor diet.
  2. Dietary practices: In many countries, people have a preference for certain foods, for example rice, samp or mealie meal. People eat a lot of this particular food type and do not get enough protein or fats and oils in their diet. They also often cannot afford other food types, especially in developing countries. However, some families in developed countries do not eat enough fruit and vegetables out of choice and eat a lot of refined carbohydrates which also leads to disease and illness.
  3. Poverty and high food prices: Poverty and high food prices stop many people from enjoying foods such as milk, meat, poultry (like chicken) and fruits. This has made it almost impossible for poor families to afford certain food groups. Some families can only afford one type of food group.
  4. Food shortage: Sometimes famine occurs in a country where drought, poor farming knowledge and skill, and a lack of technology limits the yield of crops and herds of animals. This results in a food shortage in that country.

In these situations, people will eat whatever food is available to them, often leading to an unhealthy diet.

An unhealthy diet can lead to many health problems because the body does not get the right amount of the different food groups and therefore cannot function properly.

Some diseases and conditions

It is not necessary for learners to know the difference between a disease and a condition, but generally a "disease" refers to an illness or some deviation from the normal functioning of the body or organ. A "condition", however, is a more broader term and often refers to the state of something.

Often we get diseases and conditions because our bodies do not get the necessary nourishment. Some of these diseases are:

  • Tooth decay: When you eat or drink too much sugar, the bacteria in your mouth makes acids that eat away at the tooth surface (called enamel), and causes cavities to form.
Too many sweets can cause cavities to form in your teeth.
Remember to brush your teeth to help prevent tooth decay!
  • Rickets: This is a condition mostly seen in babies and children. When children do not get enough fruit and vegetables and do not get enough Vitamin D, their bodies cannot absorb calcium and they cannot grow strong bones.
  • Constipation: This is a painful condition (not a disease) that occurs when bowel movements become difficult and take place days or even weeks apart. An unhealthy diet is often to blame, but there are other causes too. The best way to treat constipation is to eat a healthy diet with lots of fibre in the carbohydrates, to exercise regularly and to drink plenty of water.
  • Obesity: This is a condition (not a disease) where a person's body weight is more than \(\text{20}\)% that of the average weight for other people the same age and height as that person. The best prevention for obesity is to follow a healthy, balanced diet.
Obesity is a condition which is becoming more common all around the world.
  • Diabetes: This is a disease that affects the body's ability to use blood sugar for energy. Diabetes symptoms may include an increased thirst and urination, blurred vision and excessive tiredness.
  • Anorexia nervosa: This is life-threatening eating disorder where the patient starves themselves and deprives their bodies of nourishment to cause themselves to lose tremendous amounts of weight.
  • Kwashiorkor: This is a disease that affects many children. It is a lack of protein and iodine in their diet. Children suffering from this may have swollen hands and feet, and especially a very large tummy, many ulcers on the skin and their hair might discolour.

What diseases or symptoms could Farrah's brother, Rajesh, develop from his diet?


  1. Carefully read through Rajesh's diet again.
  2. Evaluate his activities in the afternoon as well.
  3. Use the information about these diseases and disorders and suggest possible diseases or conditions that Rajesh might develop if he does not change his diet drastically.


What in Rajesh 's diet could cause this disease?



What in Rajesh's diet could cause this disease?


Overeating and inactivity


Possibly because of the small amount of fruit and vegetables eaten


Eating far too much sugar and starches, inactivity


Rajesh is very inactive and almost never drinks any water!

Research one of the diseases

This can be used as a possible project, where learners can also present their posters to the class and practise their oral skills. Be sensitive to the fact that some children in your class may suffer from some of these diet-related diseases.


  • books from the library, information from the internet
  • sheets of paper
  • coloured pens and pencils


  1. Choose one of the diseases that is related to an unhealthy diet and do some extra reading and research around the topic.
  2. You must prepare a poster about this disease or condition.
  3. On your poster, you must include information about the causes of the disease, which people are most likely to suffer from it and why, the symptoms, the health risks, and any possible treatments.
  4. You might have to present your poster to the class, depending on your teacher.

  • Adiet refers to the selection of food we eat every day.
  • A balanced diet contains sufficient quantities of food from all 4 food groups, as well as water and fibre.
  • Some diseases can be related to diet.

What do you understand by the term "balanced diet"? Write a description below.

Draw a food pyramid of the food that you eat and assess whether it has the correct shape of a balanced diet.

(Mark individual learner's food pyramids based on the one used earlier in the book.)

Rajesh thinks that he can get enough water in his diet by drinking Coke and coffee with sugar in it. Explain to him if this is true or not and why.

Write a paragraph where you explain some of the possible causes of a poor diet.