Classes of Food, Nutrient and Nutrition Basic 4 Home Economics Lesson Note

What is Nutrition?

Nutrition is the process of taking in food and using it for growth, health, and energy in our body.

What are Nutrients?

Nutrients are the useful substances in food that our body needs to grow, stay healthy, and work properly.

What are Classes of Food?

Classes of food are groups of foods that provide similar nutrients and serve similar purposes in our body.

The 3 Main Classes of Food

1. Energy-Giving Foods (GO FOODS)

Foods that provide energy for our daily activities

Main Nutrient: Carbohydrates and Fats

• Carbohydrates: Body’s main source of energy
• Fats: Concentrated source of energy

Functions:

• Provide energy for running, playing, walking
• Fuel for brain to think and learn
• Power for body organs like heart and lungs
• Keep body warm especially fats

Food Sources:

Carbohydrate Foods:

• Grains: Rice, bread, wheat, oats, millet
• Root crops: Yam, cassava, sweet potato, Irish potato
• Fruits: Bananas, plantains, dates
• Sugary foods: Honey, sugar

Fat Foods:

• Oils: Palm oil, groundnut oil, coconut oil
• Nuts: Groundnuts, cashews, walnuts
• Animal fats: Butter, meat fat
• Others: Avocado, coconut

Signs You Need Energy Foods:

• Feeling tired and weak
• Cannot concentrate in school
• No energy to play
• Feeling hungry often

2. Body-Building Foods (GROW FOODS)

Foods that help us grow and build strong muscles

Main Nutrient: Proteins

• Complete proteins: From animals (have all essential parts)
• Incomplete proteins: From plants (missing some parts)

Functions:

• Build muscles and make us strong
• Help children grow taller and bigger
• Repair body parts when injured
• Make antibodies to fight diseases
• Build blood, bones, and organs

Food Sources:

Animal Proteins:

• Meat: Beef, goat meat, chicken, turkey
• Fish: Fresh fish, dried fish, canned fish
• Dairy: Milk, cheese, yogurt
• Eggs: Chicken eggs, duck eggs

Plant Proteins:

• Legumes: Beans, cowpeas, soybeans, lentils
• Nuts: Groundnuts, cashews, walnuts
• Seeds: Melon seeds, pumpkin seeds

Signs You Need Protein Foods:

• Slow growth in children
• Weak muscles
• Getting sick often
• Wounds heal slowly
• Thin, weak hair

3. Protective Foods (GLOW FOODS)

Foods that protect us from diseases and keep us healthy

Main Nutrients: Vitamins and Minerals

• Vitamins: Help body work properly
• Minerals: Build strong bones and healthy blood

Functions:

• Boost immune system to fight diseases
• Keep skin, eyes, and hair healthy
• Help wounds heal quickly
• Make bones and teeth strong
• Help other nutrients work properly

Food Sources:

Vitamin-Rich Foods:

• Fruits: Oranges, mangoes, guavas, tomatoes, pawpaw
• Vegetables: Spinach, carrots, pepper, green leafy vegetables
• Others: Liver, eggs, milk

Mineral-Rich Foods:

• Calcium foods: Milk, cheese, fish with bones, leafy vegetables
• Iron foods: Meat, liver, beans, spinach, garden egg leaves
• Other minerals: Various fruits and vegetables

Signs You Need Protective Foods:

• Getting sick often
• Slow healing wounds
• Poor eyesight (especially at night)
• Weak bones and teeth
• Pale skin and lips

Important Nutrients and Their Functions

1. Carbohydrates

• Function: Main source of energy
• Sources: Rice, yam, bread, cassava, sugar
• Daily need: Should be largest part of meals

2. Proteins

• Function: Building and repairing body
• Sources: Meat, fish, beans, eggs, milk
• Daily need: Include in every meal

3. Fats and Oils

• Function: Concentrated energy, insulation
• Sources: Palm oil, nuts, butter, avocado
• Daily need: Small amounts needed

4. Vitamins

• Vitamin A: Good eyesight, healthy skin
• Vitamin C: Fight diseases, heal wounds
• Vitamin D: Strong bones and teeth
• B Vitamins: Energy production, healthy nerves

5. Minerals

• Calcium: Strong bones and teeth
• Iron: Healthy blood, prevent anemia
• Iodine: Proper growth and brain development

6. Water

• Function: Transport nutrients, remove waste, cool body
• Sources: Plain water, fruits, vegetables
• Daily need: 6-8 glasses for children

Balanced Diet

What is a Balanced Diet?

A balanced diet contains foods from all three classes in the right amounts to keep us healthy.

Components of Balanced Diet:

• Energy foods: 50-60% of daily food
• Body-building foods: 15-20% of daily food
• Protective foods: 20-25% of daily food
• Water: Plenty throughout the day

Nigerian Balanced Meal Examples:

Breakfast:

• Energy: Bread or pap
• Protein: Egg or milk
• Protective: Orange or tomato

Lunch:

• Energy: Rice or yam
• Protein: Fish or meat or beans
• Protective: Vegetable soup or salad

Dinner:

• Energy: Cassava or plantain
• Protein: Chicken or beans
• Protective: Spinach or pepper soup

Signs of Good Nutrition

Physical Signs:

• Healthy appearance: Bright eyes, clear skin, shiny hair
• Normal growth: Growing at expected rate for age
• Good energy: Active and alert throughout day
• Strong immunity: Don’t get sick often
• Healthy weight: Not too thin or too fat

Mental Signs:

• Good concentration: Can focus in school
• Happy mood: Generally cheerful and positive
• Good memory: Remember things well
• Alert mind: Think clearly and learn easily

Problems of Poor Nutrition

Malnutrition:

Not getting enough nutrients or wrong balance of nutrients

Common Problems:

• Kwashiorkor: Not enough protein (swollen belly, thin hair)
• Marasmus: Not enough food overall (very thin)
• Anemia: Not enough iron (tiredness, pale skin)
• Night blindness: Not enough Vitamin A
• Rickets: Not enough Vitamin D and calcium (bent bones)

Prevention:

• Eat variety of foods from all classes
• Regular meals at proper times
• Clean, safe food preparation
• Adequate amounts according to age and activity

EXERCISES

Exercise 1: Fill in the Blanks

1. ________ is the process of taking in food for growth and health
2. The three main classes of food are energy-giving, body-building, and ________
3. ________ foods help us grow and build strong muscles
4. A ________ diet contains foods from all three classes

Exercise 2: True or False

1. Energy-giving foods provide power for daily activities ____
2. Proteins are only found in animal foods ____
3. Protective foods help fight diseases ____
4. We only need nutrients from one class of food ____

Exercise 3: Match Food Class with Function

Draw lines to connect each class with its main function:

• Energy-giving foods → Help us grow and build muscles
• Body-building foods → Protect us from diseases
• Protective foods → Give us energy for activities

Exercise 4: Food Classification

Write “E” for Energy-giving, “B” for Body-building, or “P” for Protective:

1. Rice ____
2. Fish ____
3. Oranges ____
4. Yam ____
5. Beans ____
6. Carrots ____

Exercise 5: Choose the Right Answer

Circle the correct answer:

1. Main nutrient in energy foods: Proteins / Carbohydrates
2. Proteins help with: Giving energy / Building muscles
3. Vitamins are found in: Only fruits / Fruits and vegetables
4. Water should be: 6-8 glasses daily / 1-2 glasses daily