Components of Food - Nutrients including carbohydrates, proteins, fats, vitamins, and balanced diet
Class 6 Science: Components of Food & The Balanced Diet
Hello, young scientists! Welcome to an exciting journey into the world of Science.
Have you ever wondered why your parents constantly remind you to finish your vegetables, drink your milk, or avoid eating junk food all the time? Why do we feel hungry after playing sports, and where do we get the energy to run, write, think, and grow?
The answer lies in the food we eat! Just like a car needs petrol or diesel to run, our body needs food to stay active, grow big and strong, and protect itself from illness.
In this chapter, we will explore what food is actually made of and why different components of food are essential for our body.
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1. What are Nutrients? (The Superheroes of Food)
When you look at your lunch plate (a classic Indian *Thali*), you might see rice, dal, a green vegetable dish (*sabzi*), a spoonful of ghee, and some curd. Each of these food items contains special chemical substances that our body needs to survive and grow.
These chemical components present in food are called Nutrients.
Think of nutrients as a team of superheroes, where each superhero has a specific superpower to keep your body working smoothly:
In addition to these five major nutrients, our body also needs Dietary Fibres (Roughage) and Water. Let us meet each superhero one by one!
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2. Carbohydrates: The Fuel Tank of Your Body
What are they?
Carbohydrates are the main source of energy for our body. Whenever you walk, jump, study, or even breathe, your body uses carbohydrates to power these actions. Because they provide energy, food rich in carbohydrates is called Energy-giving food.
Types of Carbohydrates:
In our food, carbohydrates mainly exist in two forms:
```
[ Carbohydrates ]
/ \
Sugars Starch
(Quick Energy) (Slow Energy)
```
Main Sources of Carbohydrates:
> Real-World Analogy: Think of carbohydrates like the petrol in a car. Without petrol, a car cannot move even a single inch. Similarly, without carbohydrates, you would feel weak, tired, and lazy!
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3. Fats: The Extra Energy Storage Bank
What are they?
Like carbohydrates, Fats also provide energy to our body. In fact, fats give much more energy than carbohydrates for the same amount!
Food items rich in fats are also classified as Energy-giving foods.
Functions of Fats:
Main Sources of Fats:
Fats come from both plants and animals:
> Caution Note: While fats are essential, eating *too much* fat is unhealthy! When we eat excess fatty food without exercising, our body stores the extra fat, leading to a condition called obesity (being overweight).
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4. Proteins: The Master Builders
What are they?
When you scrape your knee, how does the skin heal after a few days? How do you grow taller every year?
The answer is Proteins! Proteins are nutrients needed for the growth and repair of our body. That is why protein-rich foods are famously known as Body-building foods.
Why do kids need more protein?
Growing children need relatively more proteins in their diet than adults because their bones, muscles, and tissues are growing rapidly every day!
Main Sources of Proteins:
> Real-World Analogy: Imagine you are building a brick house. Proteins are like the bricks used to build the walls and fix broken spots.
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5. Vitamins and Minerals: The Protective Armor
While carbohydrates, fats, and proteins are needed in larger amounts, Vitamins and Minerals are required in small quantities. However, they are super important!
They protect our body against diseases and keep our eyes, bones, teeth, and gums healthy. Thus, foods containing vitamins and minerals are called Protective foods.
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A) Vitamins
Different vitamins perform different jobs in the body. Here is a handy reference guide:
| Vitamin | Function in the Body | Good Food Sources |
| :--- | :--- | :--- |
| Vitamin A | Keeps eyes and skin healthy | Papaya, carrot, mango, milk, fish oil |
| Vitamin B-Complex | Helps produce energy, keeps nervous system healthy | Whole grains, rice, wheat, liver |
| Vitamin C | Helps body fight against diseases, keeps gums healthy | Amla, orange, lemon, tomato, guava |
| Vitamin D | Helps body use calcium for strong bones and teeth | Milk, butter, eggs, fish, Sunlight |
> Fun Fact: Our body actually prepares Vitamin D in the presence of sunlight! That is why playing in the morning sun is great for your bones.
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B) Minerals
Minerals are inorganic elements needed by our body to build strong structures and perform biological processes.
* *Sources:* Milk, curd, eggs, green leafy vegetables.
* *Sources:* Spinach, apples, jaggery (*gur*), liver.
* *Sources:* Iodised salt, seafood, fish.
* *Sources:* Milk, banana, wheat, rice.
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6. Dietary Fibres (Roughage) and Water
Even though dietary fibres and water do not provide nutrients directly, our body cannot survive without them!
Dietary Fibres (Roughage)
Water
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7. What is a Balanced Diet?
Eating food is not just about filling your stomach; it is about filling your body with the right balance of nutrients.
> Definition: A Balanced Diet is a diet that contains all the essential nutrients (carbohydrates, fats, proteins, vitamins, minerals) in the right quantities, along with an adequate amount of roughage and water.
```
+--------------------------+
| THE BALANCED PLATE |
+--------------------------+
| Energy Foods: Rice/Roti |
| Body Builders: Dal/Milk |
| Protective Foods: Veggies|
| Roughage & Water |
+--------------------------+
```
Points to Remember for a Balanced Diet:
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8. What Happens When We Lack Nutrients? (Deficiency Diseases)
If a person eats a diet that lacks a specific nutrient over a long period of time, they may suffer from a Deficiency Disease.
Here are some common deficiency diseases given in the NCERT syllabus:
| Deficiency Nutrient | Disease / Disorder | Common Symptoms |
| :--- | :--- | :--- |
| Vitamin A | Loss of Vision (Night Blindness) | Poor vision, difficulty seeing in darkness/night |
| Vitamin B1 | Beriberi | Weak muscles, very little energy to work |
| Vitamin C | Scurvy | Bleeding gums, wounds take longer time to heal |
| Vitamin D | Rickets | Bones become soft and bent |
| Calcium | Bone and Tooth decay | Weak bones, tooth decay |
| Iodine | Goitre | Glands in the neck appear swollen, mental disability in children |
| Iron | Anaemia | Weakness, fatigue, pale skin |
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Summary Checklist for Revision
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Practice Time!
Test your knowledge with these practice questions! Try answering them on your own before reading the detailed solutions.
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Question 1 (Multiple Choice / Conceptual)
Rohan’s grandfather has trouble seeing things clearly in the evening and during the night. The doctor advised him to eat more carrots, papayas, and green leafy vegetables.
(a) Which vitamin is Rohan's grandfather likely deficient in?
(b) Name the deficiency disease associated with it.
(c) What type of food group do carrots and papayas belong to based on their general function?
#### Solution:
(a) Rohan's grandfather is likely deficient in Vitamin A. Vitamin A is essential for maintaining good vision and healthy eyes.
(b) The deficiency disease associated with the lack of Vitamin A is Loss of Vision (commonly called Night Blindness).
(c) Carrots and papayas are rich in vitamins, so they belong to the Protective Foods group, which helps protect our body from diseases and keeps us healthy.
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Question 2 (Short Answer / Reasoning)
A child eats only white rice, boiled potatoes, and butter every day.
(a) Will this diet keep the child healthy over a long time? Give a reason for your answer.
(b) What essential nutrient classes are missing from this diet, and what problems might arise due to their absence?
#### Solution:
(a) No, this diet will not keep the child healthy over time. Rice, potatoes, and butter provide mainly carbohydrates and fats (energy-giving nutrients), but they lack other essential nutrients required for complete health. This is not a balanced diet.
(b) The diet is missing:
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Question 3 (Long Answer / Application)
Differentiate between Carbohydrates and Proteins based on:
#### Solution:
| Feature | Carbohydrates | Proteins |
| :--- | :--- | :--- |
| 1. Primary Function | Provide energy to perform daily activities and physical work. | Help in the growth, development, and repair of damaged tissues. |
| 2. Common Category | Known as Energy-giving foods. | Known as Body-building foods. |
| 3. Plant Source | Wheat / Rice / Potato | Gram (Chana) / Rajma / Soybeans |
| 4. Animal/Other Source | Milk (contains lactose sugar) | Milk / Paneer / Eggs / Fish |
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*Keep studying, stay curious, and remember to eat a balanced plate every single day!*