Chapter 5 of 10

50%

Tamil Nadu (TNBSE)Class 3 Science★ 5-6 marks in TN Class 3 Term 2 exams — nutrient classification, balanced diet composition, and short written answers

Food

Samacheer Kalvi (TN State Board) Class 3 Science — Chapter 5, Food. Nutrients and cooking methods. Study notes, key concepts, worked examples, practice questions and quick revision for exam preparation.

⏱ 10 min readeasy-to-medium difficulty✓ Free · NCERT-aligned

Worksheet

Podcast

Listen as a conversation

A teacher & a student talk through the chapter — in your language.

Mind Map

The chapter at a glance

Every concept and exam-favourite branch — revisable in 5 minutes.

…

Study Guide

Night-before notes

Key points, glossary and the questions most likely to show up.

…

VocabularyBuild your vocabularyLexiGenome mines the key words and schedules them with spaced repetition.Mine words →

By the end of this chapter you'll be able to…

1Name the 5 nutrients: carbohydrates, proteins, fats, vitamins, and minerals
2State the function of each nutrient: carbohydrates and fats → give energy; proteins → build and repair the body; vitamins and minerals → protect against diseases
3Give 2-3 food sources for each nutrient with Tamil context (rice/idli for carbs, dal/egg for protein, ghee/oil for fat, fruits/greens for vitamins, milk/salt for minerals)
4Define a balanced diet as one that contains all nutrients in the right amounts, plus fibre and water
5Name the three main meals in a day: breakfast, lunch, dinner
6List 3 traditional Tamil foods and their nutritional benefits: idli (fermented, easy to digest), sambar (protein + vegetables), keerai (iron-rich greens)
7Explain the benefits of a home garden: fresh, pesticide-free vegetables; saves money; a good physical activity

💡

Why this chapter matters

Food is fuel for the human body. Class 3 goes beyond 'eat healthy' to introduce the five nutrients — carbohydrates, proteins, fats, vitamins, and minerals — and what each one does. Children learn to read their own plate: rice gives energy (carbohydrates), dal builds muscle (protein), ghee provides warmth (fat), vegetables protect against illness (vitamins and minerals). This chapter also celebrates traditional Tamil food wisdom — fermented foods like idli and dosa, the protein-rich sambar-rice combination, and the concept of a home garden (thottam). A balanced diet is not some western concept — it is embedded in every traditional Tamil meal served on a banana leaf.

Before you start — revise these

A 5-minute refresher here will save you 30 minutes of confusion below.

🔗

Food — Class 3 Science (Samacheer Kalvi)

TN State Board (Samacheer Kalvi) Class 3 Science, Chapter 5. Nutrients and cooking methods.

1. About this chapter

This chapter covers Food as part of the Class 3 Samacheer Kalvi Science curriculum. It deals with nutrients and cooking methods and builds conceptual understanding essential for the TN School Term Exam.

By the end of this chapter, students will be able to:

Name the types of nutrients
Explain why cooking food is important

2. Key concepts

Concept 1: Name the types of nutrients.
Concept 2: Explain why cooking food is important.

3. Important terms and formulas

Term / Formula	Description
Name the types of…	Name the types of nutrients
Explain why cooking food…	Explain why cooking food is important

4. Worked examples

Example 1. Applying a key concept from this chapter.

Solution: Identify the relevant principle → apply the formula or rule → state the answer with correct units.

Example 2. A typical exam-style question on food.

Solution: Break the problem into steps, use the appropriate formula and verify the answer.

5. Common mistakes

Mistake: Skipping units or forgetting to state them. Fix: Always write units alongside every quantity and answer.
Mistake: Confusing similar terms or concepts in this chapter. Fix: Make a comparison table of the terms during revision.

6. Practice (exam-style)

Define the main term or principle covered in Chapter 5.
Give two real-life examples related to food.
Solve a short numerical or descriptive question from this chapter.
State one important formula and explain each symbol.

7. Answer key (hints)

Refer to section 2 (Key concepts) above for the definition.
Examples should be drawn from daily experience and local context.
Apply the formula from section 3, show all steps clearly.
Formula with units — refer to the textbook glossary for symbol meanings.

8. Quick revision

Class 3 Science — Chapter 5: Food.
Core idea: Nutrients and cooking methods.
Key outcomes: Name the types of nutrients; Explain why cooking food is important.
Always revise diagrams / tables from the Samacheer Kalvi textbook before the exam.

Key formulas & results

Everything you need to memorise, in one card. Screenshot this for revision.

The five nutrients

Carbohydrates → main energy source. Sources: rice, wheat, ragi, idli, dosa, chapati, potato. Proteins → build and repair muscles, skin, hair. Sources: dal, milk, egg, fish, soya bean, paneer. Fats → stored energy, keep body warm. Sources: ghee, butter, oil, nuts. Vitamins → protect against diseases, help body functions. Sources: fruits (especially citrus for Vitamin C), green leafy vegetables, carrot (Vitamin A). Minerals → strong bones, teeth, healthy blood. Sources: milk (calcium), salt (iodine), spinach (iron), banana (potassium).

No single food contains all nutrients. That is why we need a balanced diet. Even rice — the staple of Tamil Nadu — is mainly carbohydrate and needs dal (protein), vegetables (vitamins), and a drop of ghee (fat) to make a complete meal.

Balanced diet

A balanced diet = carbohydrates (energy) + proteins (body-building) + fats (stored energy) + vitamins & minerals (protection) + fibre (digestion) + water (hydration). All in the right amounts.

A traditional Tamil sappadu (meal) served on a banana leaf is a naturally balanced diet: rice (carbs), sambar/dal (protein), poriyal (vegetables + vitamins), curd (calcium), pickle (minerals, digestion), and a banana (fruit). No dietician could design it better.

Traditional Tamil foods and their benefits

Idli/Dosa → fermented rice and urad dal batter. Fermentation increases Vitamin B and makes it easy to digest. Sambar → made with toor dal (protein) and vegetables like drumstick, brinjal, pumpkin (vitamins and fibre). Keerai (greens) → araikeerai, mulai keerai, and siru keerai are incredibly rich in iron and calcium. Ragi (finger millet/கேழ்வரகு) → rich in calcium, good for bones. Buttermilk/Moru → rich in calcium and probiotics for gut health.

Most traditional Tamil foods were designed centuries ago with nutrition science embedded in cultural practice. Eating idli with sambar is not just tasty — it combines fermented grains (easy digestion) with protein and vegetables.

Home garden (Thottam)

Growing vegetables, greens, and herbs at home: curry leaves (karuveppilai), coriander (kothamalli), tomatoes, chillies, brinjal, and greens (keerai) can all be grown in small spaces — even in pots on a terrace or balcony. Benefits: fresh, pesticide-free food; saves money; physical activity; satisfaction of eating what you grew.

Children can start with a single pot of coriander or curry leaves. Water it daily, give it sunlight, and watch it grow. This is science in action — the same chapter that teaches about nutrients also teaches how to grow them.

⚠️

Common mistakes & fixes

These are the exact errors that cost students marks in board exams. Read them once, save yourself the trouble.

WATCH OUT

✗ Thinking carbohydrates are 'bad' and should be avoided

✓ Carbohydrates are the body's primary source of energy — especially for growing children who run, play, and study all day. The problem is EXCESS carbs (especially from processed sugars like soft drinks and sweets), not carbs from rice, idli, and whole grains.

WATCH OUT

✗ Skipping vegetables because they 'don't taste good'

✓ Vegetables provide vitamins and minerals that no other food group can fully replace. Without them, you may fall sick more often, have weak bones, and get tired easily. Try different vegetables cooked in different ways — beetroot poriyal, carrot kheer, pumpkin sambar.

WATCH OUT

✗ Thinking supplements (pills/syrups) can replace food

✓ A vitamin pill cannot replace a balanced meal. Real food contains fibre, antioxidants, and hundreds of beneficial compounds that pills cannot replicate. Eat real food, not supplements — unless prescribed by a doctor.

WATCH OUT

✗ Drinking water only when thirsty

✓ By the time you feel thirsty, your body is already slightly dehydrated. Drink water regularly throughout the day — 6-8 glasses. Water is an essential part of a balanced diet even though it is not a 'nutrient'.

AI helpers for this chapter

Generate more practice on the fly, or have the chapter explained at a different level.

⚡

Generate 5 more questions

Fresh MCQs + short-answer items based on this chapter, plus answer keys.

🧠

Explain at a different level

Re-explain the chapter at the level you actually want.

📝 My notes

Saved on this device — sign in to sync · how this works

0/600

Practice more, ask doubts, find a tutor

Tamil Nadu (TNBSE) Class 3 mock tests

Tamil Nadu (TNBSE) Class 3 PYQs

Ask in Q&A

Science flashcards

Related chapters

Students who read Food usually read these next.

My Body

Samacheer Kalvi (TN State Board) Class 3 Science — Chapter 1, My Body. Sensory organs and personal hygiene. Study notes, key concepts, worked examples, practice questions and quick revision for exam preparation.

States of Matter

Samacheer Kalvi (TN State Board) Class 3 Science — Chapter 2, States of Matter. Solids, liquids and gases. Study notes, key concepts, worked examples, practice questions and quick revision for exam preparation.

Force

Samacheer Kalvi (TN State Board) Class 3 Science — Chapter 3, Force. Push, pull and friction in daily life. Study notes, key concepts, worked examples, practice questions and quick revision for exam preparation.

Science in Everyday Life

Samacheer Kalvi (TN State Board) Class 3 Science — Chapter 4, Science in Everyday Life. Simple machines and tools. Study notes, key concepts, worked examples, practice questions and quick revision for exam preparation.