Functions of Food in the Body, Growth, Regulation and Disease Protection for SS 1

Class: SS 1
Term: First Term
Week: 3
Age: 15 years
Duration: 60 minutes
Subject: Food and Nutrition
Curriculum Theme: Food Nutrients for Healthy Living
Focal competence: Applying knowledge of food nutrients based on their composition for healthy meal planning
Key competencies/values: Collaboration; ICT and Digital Competencies
Skills:

• Classifying foods based on their origin, nutrient content and functions

Previous Lesson: Classification of foods according to origin, nutrients and function
Topic: Introduction To Foods And Nutrition: Functions Of Food In The Body
Subject Matter: Functions of food in the body, builds and repairs tissue, regulates body processes, protects against disease

Specific Objectives

By the end of the lesson, pupils/students should be able to:

Cognitive Domain

• Identify the four main functions of food in the body.
• Explain the importance of each function of food.
• Propose simple solutions to nutritional problems based on food functions.

Affective Domain

• Appreciate the importance of a balanced diet for overall health.
• Collaborate effectively with peers during group activities.

Psychomotor Domain

• Classify familiar foods according to their primary function in the body.
• Demonstrate the use of digital devices to research food functions.

Social Domain

• Participate actively in discussions about food and nutrition for healthy living.

Reference Materials

The following resources were used in planning this lesson:

• 2025 New Revised Senior Secondary Education Curriculum (SSEC)
• Relevant State Unified Scheme of Work
• A suitable Food and Nutrition textbook for SS 1
• The HeadTeacher Scheme of work For The New Revised Senior Secondary Education Curriculum (SSEC)

Instructional Materials

The teacher will teach this lesson with the aid of:

• Charts/posters showing food classification (e.g., food pyramid, food groups)
• Internet-enabled devices (e.g., tablets, smartphones, computer with projector)
• Video clips on functions of food and consequences of poor nutrition
• Pictures of various food items

Rationale for the Lesson

Understanding the functions of food is foundational to making informed dietary choices and maintaining good health. This lesson helps students recognise how different foods contribute to their body’s energy, growth, repair, regulation, and protection against diseases. This knowledge empowers them to plan healthier meals and appreciate the link between nutrition and overall well-being.

Prerequisite/Previous Knowledge

Students should have a basic understanding of what food is and some common food items they consume daily.

Lesson Content/Board Summary

Functions of Food in the Body

Introduction to Food Functions

Food is essential for human life. It provides the necessary substances that enable the body to grow, develop, stay healthy, and perform daily activities. The primary functions of food can be categorised into four main areas: providing energy, building and repairing tissues, regulating body processes, and protecting against diseases.

Provides Energy

Energy is required for all bodily activities, from breathing and thinking to walking and running. Foods rich in carbohydrates and fats are the main sources of energy for the body.

1. Carbohydrates: These are the body’s preferred source of energy. They are broken down into glucose, which fuels cells, tissues, and organs.
   1. Examples: Yam, rice, maize, cassava, bread, pasta, potatoes, plantain, sugar.
   2. Health Relevance: Adequate carbohydrate intake prevents the body from breaking down protein for energy, preserving it for tissue building.
   3. Practical Household Examples: Eating a plate of jollof rice for sustained energy during school activities, or consuming garri to feel full and energetic.
2. Fats and Oils: These provide a more concentrated source of energy than carbohydrates. They also help in the absorption of fat-soluble vitamins.
   1. Examples: Groundnut oil, palm oil, butter, margarine, nuts, avocado, fatty fish.
   2. Health Relevance: Essential for energy storage and insulation, but excessive intake can lead to health issues like obesity.
   3. Practical Household Examples: Using palm oil to cook soup or stew, or adding groundnuts to snacks for extra energy.

Builds and Repairs Tissue

The body is constantly growing, and old cells are regularly replaced. Proteins are the primary nutrients responsible for building new tissues and repairing damaged ones.

1. Proteins: These are the building blocks of the body. They are crucial for the growth of muscles, hair, skin, and organs, and for repairing injuries.
   1. Examples: Meat, fish, eggs, milk, beans, groundnuts, soy products.
   2. Health Relevance: Essential for growth in children and adolescents, and for recovery from illness or injury in adults.
   3. Practical Household Examples: Eating beans for growth and muscle development, or consuming fish to aid in wound healing.

Regulates Body Processes

Many vital processes in the body, such as digestion, metabolism, nerve function, and fluid balance, are regulated by specific nutrients. Vitamins, minerals, water, and fibre play key roles in these regulatory functions.

1. Vitamins: These are organic compounds needed in small quantities for various metabolic processes.
   1. Examples: Vitamin A (carrots, liver), Vitamin C (oranges, tomatoes), B vitamins (whole grains, meat).
   2. Health Relevance: Vitamin C is vital for a healthy immune system, while B vitamins are crucial for energy metabolism.
   3. Practical Household Examples: Drinking orange juice for Vitamin C, or eating leafy green vegetables for various vitamins.
2. Minerals: These are inorganic elements required for bone formation, nerve function, and fluid balance.
   1. Examples: Calcium (milk, leafy greens), Iron (red meat, spinach), Potassium (banana, potatoes).
   2. Health Relevance: Calcium is essential for strong bones and teeth, while iron is needed for blood formation and preventing anaemia.
   3. Practical Household Examples: Consuming milk for calcium to strengthen bones, or eating spinach to get iron.
3. Water: Although not a nutrient in the traditional sense, water is vital for life. It regulates body temperature, transports nutrients, and aids in waste removal.
   1. Health Relevance: Dehydration can lead to fatigue, headaches, and impaired bodily functions.
   2. Hygiene/Safety Considerations: Always drink clean, safe water to avoid waterborne diseases.
   3. Practical Household Examples: Drinking water throughout the day to stay hydrated, especially in hot weather.
4. Fibre (Roughage): This is the indigestible part of plant foods. It aids digestion and prevents constipation.
   1. Examples: Whole grains, fruits, vegetables, legumes.
   2. Health Relevance: Promotes bowel regularity and can help prevent certain digestive disorders.
   3. Practical Household Examples: Eating fruits like oranges or apples with their skin, or including vegetables in meals.

Protects Against Disease

A well-nourished body has a stronger immune system, making it more resistant to infections and diseases. Certain vitamins, minerals, and antioxidants contribute significantly to this protective function.

1. Vitamins and Minerals: Many vitamins (e.g., A, C, E) and minerals (e.g., zinc, selenium) act as antioxidants or support immune cell function.
   1. Examples: Citrus fruits, bell peppers, dark leafy greens, berries, nuts, seeds.
   2. Health Relevance: Regular intake boosts immunity, reducing the risk of common colds, flu, and chronic diseases.
   3. Hygiene/Safety Considerations: Wash fruits and vegetables thoroughly before consumption to remove germs and pesticides.
   4. Practical Household Examples: Eating a variety of colourful fruits and vegetables daily to boost immunity.
2. Antioxidants: These compounds protect body cells from damage caused by free radicals, which can lead to chronic diseases like cancer and heart disease.
   1. Examples: Found in many fruits, vegetables, and whole grains.
   2. Health Relevance: Reduces oxidative stress and inflammation in the body.

Teaching Methods/Instructional Techniques

Discussion, Explanation, Question and Answer, Group Work, Demonstration, Guided Practice, Visual Aids

Instructional Procedures

Step 1: Introduction

Time: 5 minutes

Teaching Skill: Questioning/Engagement

Teacher’s Activity: The teacher greets the students and asks them what they had for breakfast or their last meal. The teacher then asks why they eat food.

Pupils’ Activity: Pupils respond to the teacher’s questions, sharing their meals and initial thoughts on why food is important.

Learning Point: Importance of food

Step 2: Exploring Functions of Food (Energy)

Time: 10 minutes

Teaching Skill: Explanation/Visualisation

Teacher’s Activity: The teacher introduces the first function of food: providing energy. Using charts or video clips, the teacher explains how carbohydrates and fats give the body energy for various activities. The teacher asks students to identify energy-giving foods from the charts.

Pupils’ Activity: Pupils observe the charts/video, listen to the explanation, and identify energy-giving foods.

Learning Point: Food provides energy

Step 3: Exploring Functions of Food (Building and Repairing)

Time: 10 minutes

Teaching Skill: Explanation/Discussion

Teacher’s Activity: The teacher moves to the second function: building and repairing tissues. The teacher explains the role of protein in growth and healing, showing examples of protein-rich foods. The teacher also discusses the consequences of poor nutrition related to growth.

Pupils’ Activity: Pupils listen, ask questions, and identify body-building foods. They discuss consequences of protein deficiency.

Learning Point: Food builds tissues

Step 4: Exploring Functions of Food (Regulation and Protection)

Time: 10 minutes

Teaching Skill: Explanation/Demonstration

Teacher’s Activity: The teacher explains the third and fourth functions: regulating body processes and protecting against disease. The teacher highlights the roles of vitamins, minerals, water, and fibre. Using internet-enabled devices, the teacher might show a short clip on how vitamins boost immunity or discuss careers in Food and Nutrition.

Pupils’ Activity: Pupils pay attention, take notes, and participate in discussions about regulatory and protective foods and their health relevance.

Learning Point: Food regulates and protects

Step 5: Group Brainstorming and Classification

Time: 10 minutes

Teaching Skill: Group Work/Facilitation

Teacher’s Activity: The teacher divides students into groups and guides them to brainstorm on the importance of food and nutrition. Each group is given pictures of various foods and tasked to classify them according to their primary function (energy, body-building, regulatory/protective).

Pupils’ Activity: Pupils work in groups, discuss the importance of food, and classify the food pictures into their respective functional categories.

Learning Point: Classifying food functions

Step 6: Group Presentation and Discussion

Time: 5 minutes

Teaching Skill: Presentation/Feedback

Teacher’s Activity: The teacher asks each group to present their classification and explain their choices. The teacher provides feedback and clarifies any misconceptions, reinforcing the health relevance and hygiene considerations.

Pupils’ Activity: Groups present their work, and other pupils listen and ask questions. They receive feedback from the teacher.

Learning Point: Reinforcing food functions

Step 7: Evaluation/Review

Time: 5 minutes

Teaching Skill: Questioning/Assessment

Teacher’s Activity: The teacher evaluates the learning by asking the following questions:

1. State the four main functions of food in the body.
2. Give two examples of foods that provide energy.
3. Why is protein important for growing children?
4. How do vitamins and minerals protect the body from disease?

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Understanding food functions

Step 8: Note-Taking

Time: 10 minutes

Teaching Skill: Guided Writing

Teacher’s Activity: The teacher guides pupils/students to copy the essential Board Summary notes on the functions of food in the body into their notebooks.

Pupils’ Activity: Pupils/students copy the notes carefully into their notebooks.

Learning Point: Recording lesson notes

Step 9: Conclusion

Time: 5 minutes

Teaching Skill: Summarisation

Teacher’s Activity: The teacher summarises the lesson by reiterating the four main functions of food and encouraging students to apply this knowledge in their daily food choices for a healthy life. The teacher also briefly mentions the importance of food hygiene.

Pupils’ Activity: Pupils listen attentively and ask any final questions.

Learning Point: Consolidating food functions

Continuous Assessment/Further Study

Type: Homework/Further Reading

Instruction: Answer the following questions in your notebook and research one career in Food and Nutrition.

1. List three foods that are good for building and repairing tissues and explain why.
2. Describe two ways food helps to regulate body processes.
3. Suggest a simple meal plan for a student that incorporates foods for all four functions.
4. Research and write a short paragraph about one career opportunity in the field of Food and Nutrition (e.g., Dietitian, Food Scientist, Chef).

Lesson Keywords

• Energy – The power needed to do things, supplied by food.
• Tissue – Groups of cells that work together, like muscle or skin, built and repaired by food.
• Regulate – To control or adjust a process, a function of certain nutrients.
• Protection – Guarding against harm, like diseases, provided by specific foods.
• Carbohydrates – Main source of energy for the body.
• Proteins – Essential for growth and repair of body tissues.
• Vitamins – Organic compounds needed for various body processes and disease protection.
• Minerals – Inorganic elements vital for body structure and function.

Differentiation

For learners needing support: The teacher will provide simplified charts with fewer food items and clearer labels, focusing on one function at a time. Pair these students with stronger peers for group activities. Provide pre-written sentence starters for their explanations.

For advanced learners: Challenge these students to research specific diseases linked to nutritional deficiencies and propose detailed dietary solutions. Encourage them to explore the biochemical processes behind each food function or investigate local Nigerian foods for each category.

Suggested Lesson Videos

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