Nutrient deficiency and excess disorders for SS 1

Class: SS 1
Term: First Term
Week: 10
Age: 15 years
Duration: 60 minutes
Subject: Food and Nutrition
Curriculum Theme: Food Nutrients for Healthy Living
Focal competence: identifying the sources and functions of food nutrients
Key competencies/values: Communication; Collaboration; ICT and Digital Competencies; Digital Competencies
Skills:

• Selecting appropriate foods based on their nutrient content

Previous Lesson: Functions of food nutrients in the body
Topic: Concept Of Food Nutrients: Nutrient Deficiency And Excess Disorders
Subject Matter: Nutrient deficiency and excess disorders

Specific Objectives

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

Cognitive Domain

• Identify common diet-related diseases caused by nutrient deficiency and excess.
• Explain the causes and symptoms of specific nutrient deficiency disorders.
• Describe the causes and health risks associated with nutrient excess disorders.
• State preventive measures for various nutrient deficiency and excess conditions.

Affective Domain

• Appreciate the importance of a balanced diet for overall health.
• Show concern for individuals suffering from diet-related disorders.

Psychomotor Domain

• Classify food samples correctly based on their potential to prevent or cause nutrient disorders.
• Demonstrate proper food hygiene practices to prevent food-borne illnesses.

Social Domain

• Collaborate with peers to discuss and share information on healthy eating habits.

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
• Food and Nutrition for Senior Secondary Schools textbook
• 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:

• Chart showing classes of food nutrients
• Real food samples (vegetables, cereal grains, legumes, fruits)
• Pictures of various food items
• Video clips on nutrient disorders
• Posters showing deficiency disorders (e.g., kwashiorkor, goiter)
• Posters showing excess disorders (e.g., obesity)

Rationale for the Lesson

This lesson is important because it educates students on the critical link between diet and health, specifically focusing on the consequences of inadequate or excessive nutrient intake. Understanding these disorders empowers students to make informed food choices, promoting personal and community well-being. It also equips them with practical knowledge to prevent common diet-related health issues in their households and beyond.

Prerequisite/Previous Knowledge

Students should have prior knowledge of the different classes of food nutrients and their basic functions in the body.

Lesson Content/Board Summary

Concept Of Food Nutrients: Nutrient Deficiency And Excess Disorders

Nutrient Deficiency Disorders

Nutrient deficiency disorders occur when the body does not receive enough of one or more essential nutrients. This can be due to insufficient intake, poor absorption, or increased nutrient requirements.

Common nutrient deficiency disorders include:

1. Kwashiorkor: This is a severe protein deficiency, often seen in children.

• Causes: Inadequate protein intake, especially when weaning from breast milk to starchy foods.
• Symptoms: Swelling (oedema), especially in the legs and face; stunted growth; skin lesions; hair changes (reddish or sparse); apathy; enlarged fatty liver.
• Prevention: Adequate intake of protein-rich foods like eggs, milk, fish, meat, and legumes.

Marasmus: This is a severe form of protein-energy malnutrition, characterised by extreme wasting.

• Causes: Chronic deficiency of both protein and total energy (calories).
• Symptoms: Severe wasting of muscle and fat; extreme thinness; stunted growth; wrinkled skin; constant hunger.
• Prevention: Adequate intake of energy and protein-rich foods.

Goiter: An enlargement of the thyroid gland, usually caused by iodine deficiency.

• Causes: Insufficient iodine in the diet, which is essential for thyroid hormone production.
• Symptoms: Visible swelling in the neck region; fatigue; weight gain; difficulty swallowing.
• Prevention: Consumption of iodised salt, seafood, and dairy products.

Anaemia: A condition where the blood lacks healthy red blood cells, most commonly due to iron deficiency.

• Causes: Insufficient iron intake, chronic blood loss, or poor iron absorption.
• Symptoms: Fatigue, weakness, pale skin, shortness of breath, dizziness.
• Prevention: Eating iron-rich foods like red meat, liver, leafy green vegetables, beans, and fortified cereals.

Rickets (in children) and Osteomalacia (in adults): Softening and weakening of bones.

• Causes: Deficiency of Vitamin D and/or calcium, essential for bone mineralisation.
• Symptoms: Bone pain, muscle weakness, bowed legs (rickets), increased risk of fractures.
• Prevention: Exposure to sunlight (for Vitamin D synthesis), consumption of Vitamin D-fortified foods, fatty fish, and calcium-rich foods like milk, cheese, and dark leafy greens.

Night Blindness: Difficulty seeing in low light conditions.

• Causes: Vitamin A deficiency.
• Symptoms: Impaired vision in dim light, dry eyes.
• Prevention: Eating Vitamin A-rich foods such as carrots, sweet potatoes, leafy green vegetables, liver, and eggs.

Scurvy: A disease resulting from a lack of Vitamin C.

• Causes: Insufficient intake of Vitamin C.
• Symptoms: Fatigue, swollen and bleeding gums, joint pain, easy bruising, poor wound healing.
• Prevention: Consumption of citrus fruits (oranges, lemons), berries, tomatoes, and leafy green vegetables.

Beriberi: A disease caused by Vitamin B1 (Thiamine) deficiency.

• Causes: Inadequate intake of Thiamine, often associated with diets primarily of polished rice.
• Symptoms: Fatigue, muscle weakness, nerve damage, heart problems.
• Prevention: Eating whole grains, legumes, pork, and fortified cereals.

Nutrient Excess Disorders

Nutrient excess disorders occur when the body receives too much of one or more nutrients. This can be due to overconsumption of certain foods, excessive use of supplements, or metabolic imbalances.

Common nutrient excess disorders include:

1. Obesity: Excessive accumulation of body fat.

• Causes: Chronic intake of more calories than the body expends, often from high-fat, high-sugar foods; lack of physical activity.
• Health Risks: Increased risk of heart disease, type 2 diabetes, high blood pressure, certain cancers, joint problems.
• Prevention: Balanced diet with appropriate portion sizes, regular physical activity, limiting processed foods and sugary drinks.

Hypervitaminosis: Toxicity from excessive intake of vitamins, particularly fat-soluble vitamins (A, D, E, K) which can accumulate in the body.

• Causes: Overuse of vitamin supplements.
• Symptoms (e.g., Hypervitaminosis A): Nausea, vomiting, headache, blurred vision, liver damage.
• Prevention: Adhering to recommended daily allowances for vitamins and avoiding excessive supplementation.

High Blood Pressure (Hypertension): Persistently elevated blood pressure.

• Causes: High intake of sodium (salt), obesity, lack of physical activity, genetics.
• Health Risks: Increased risk of heart attack, stroke, kidney disease.
• Prevention: Reducing sodium intake, eating a diet rich in fruits, vegetables, and whole grains, maintaining a healthy weight, regular exercise.

Type 2 Diabetes: A condition where the body does not use insulin properly or cannot produce enough insulin.

• Causes: Often linked to obesity, high intake of refined sugars and unhealthy fats, lack of physical activity, genetics.
• Health Risks: Heart disease, nerve damage, kidney disease, vision loss.
• Prevention: Maintaining a healthy weight, balanced diet with controlled sugar intake, regular physical activity.

Health Relevance of Balanced Nutrition

A balanced diet is crucial for:

1. Optimal growth and development in children and adolescents.
2. Maintaining a healthy immune system to fight off infections.
3. Providing energy for daily activities and bodily functions.
4. Preventing both nutrient deficiency and excess disorders.
5. Reducing the risk of chronic diseases such as heart disease, diabetes, and certain cancers.
6. Promoting mental well-being and cognitive function.

Hygiene and Safety Considerations in Food Handling

Proper food hygiene and safety are essential to prevent food-borne illnesses and preserve nutrient content. Key considerations include:

1. Washing Hands: Always wash hands thoroughly with soap and water before, during, and after preparing food.
2. Cleanliness: Keep kitchen surfaces, utensils, and cutting boards clean.
3. Separation: Separate raw meat, poultry, seafood, and eggs from other foods to prevent cross-contamination.
4. Cooking: Cook foods to their safe internal temperatures to kill harmful bacteria.
5. Chilling: Refrigerate perishable foods promptly to slow bacterial growth.
6. Water Safety: Use clean, safe water for drinking and food preparation.
7. Food Storage: Store foods properly to prevent spoilage and contamination, e.g., in airtight containers.
8. Washing Fruits and Vegetables: Wash all fruits and vegetables thoroughly under running water before consumption.

Practical Household Examples of Balanced Meals

Achieving a balanced diet at home involves combining different food groups in appropriate proportions. Examples include:

1. Breakfast: Pap/Ogi (carbohydrate) with milk (protein, calcium) and groundnuts (protein, healthy fats) or bread with egg and a fruit.
2. Lunch: Rice (carbohydrate) with stew (vegetables, oil) and fish/meat (protein) and a side of fresh fruit.
3. Dinner: Yam/Garri (carbohydrate) with vegetable soup (vegetables, oil) and chicken/beans (protein).
4. Snacks: Fruits (vitamins, fibre), nuts (protein, healthy fats), or yoghurt (protein, calcium).

Teaching Methods/Instructional Techniques

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

Instructional Procedures

Step 1: Introduction

Time: 5 minutes

Teaching Skill: Questioning/Recall

Teacher’s Activity: The teacher greets the students and asks them to recall the different classes of food nutrients and their functions. The teacher then introduces the topic by asking students what they think happens when the body does not get enough or gets too much of certain nutrients.

Pupils’ Activity: Pupils respond to the questions and share their ideas about the effects of nutrient imbalance.

Learning Point: Recalling nutrient classes

Step 2: Exploring Nutrient Deficiency Disorders

Time: 10 minutes

Teaching Skill: Explanation/Visualisation

Teacher’s Activity: The teacher displays posters showing people with various nutrient deficiency disorders (e.g., kwashiorkor, goiter, anaemia). The teacher explains what nutrient deficiency disorders are and discusses the causes, symptoms, and prevention of Kwashiorkor and Marasmus, using the visuals.

Pupils’ Activity: Students observe the posters, listen attentively, and ask questions for clarification.

Learning Point: Understanding deficiency disorders

Step 3: Further Deficiency Disorders

Time: 10 minutes

Teaching Skill: Explanation/Discussion

Teacher’s Activity: The teacher continues to explain other common nutrient deficiency disorders such as Goiter, Anaemia, Rickets/Osteomalacia, Night Blindness, Scurvy, and Beriberi, highlighting their specific nutrient deficiencies, symptoms, and preventive measures. The teacher encourages students to share any personal experiences or observations related to these conditions.

Pupils’ Activity: Students listen, take notes, and contribute to the discussion by sharing relevant experiences or asking questions.

Learning Point: Specific deficiency conditions

Step 4: Exploring Nutrient Excess Disorders

Time: 10 minutes

Teaching Skill: Explanation/Comparison

Teacher’s Activity: The teacher introduces nutrient excess disorders, explaining that too much of a good thing can also be harmful. The teacher displays posters or pictures of individuals with obesity and discusses its causes, health risks, and prevention. The teacher also briefly explains hypervitaminosis.

Pupils’ Activity: Students observe the visuals, listen to the explanations, and compare the effects of deficiency with those of excess.

Learning Point: Understanding excess disorders

Step 5: Other Excess Disorders and Health Relevance

Time: 5 minutes

Teaching Skill: Explanation/Reinforcement

Teacher’s Activity: The teacher discusses other excess disorders like high blood pressure (hypertension) and Type 2 diabetes, linking them to dietary habits. The teacher then summarises the health relevance of balanced nutrition, emphasising its role in preventing both deficiency and excess disorders.

Pupils’ Activity: Students listen and grasp the broader implications of diet on health.

Learning Point: Health implications of diet

Step 6: Hygiene, Safety and Practical Examples

Time: 5 minutes

Teaching Skill: Demonstration/Practical Application

Teacher’s Activity: The teacher discusses essential hygiene and safety considerations in food handling and preparation. The teacher then provides practical household examples of how to achieve balanced meals using local food samples, demonstrating how to classify them correctly.

Pupils’ Activity: Students observe the food samples, participate in classifying them, and discuss practical ways to apply hygiene rules at home.

Learning Point: Food hygiene and balanced meals

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. Mention two nutrient deficiency disorders and their causes.
2. State two symptoms of Kwashiorkor.
3. What is obesity and how can it be prevented?
4. Identify two ways to prevent anaemia.

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Assessing lesson understanding

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 nutrient deficiency and excess disorders 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 key points of the lesson, reiterating the importance of a balanced diet for preventing both nutrient deficiency and excess disorders. The teacher encourages students to apply what they have learned in their daily lives.

Pupils’ Activity: Pupils listen and reflect on the lesson’s main message.

Learning Point: Consolidating key concepts

Continuous Assessment/Further Study

Type: Homework

Instruction: Research and write short notes on the following:

1. How does Vitamin C deficiency affect the body?
2. List three local Nigerian foods that can help prevent iron deficiency anaemia.
3. Explain the link between excessive sugar intake and Type 2 Diabetes.
4. Suggest two practical steps your family can take to improve food hygiene at home.

Lesson Keywords

• Deficiency – A state of not having enough of something, especially a necessary component.
• Excess – An amount of something that is more than necessary, permitted, or desirable.
• Kwashiorkor – A severe protein deficiency disease.
• Marasmus – A severe protein-energy malnutrition disease.
• Goiter – Enlargement of the thyroid gland due to iodine deficiency.
• Anaemia – A condition caused by a lack of healthy red blood cells, often due to iron deficiency.
• Obesity – The condition of being grossly fat or overweight.
• Hypervitaminosis – A condition caused by an excessive intake of vitamins.

Differentiation

For students who grasp concepts quickly, encourage them to research specific case studies of nutrient disorders in their local community or globally. Provide additional visual aids and simplified explanations for students who require more support, focusing on one disorder at a time with clear, concise information.

Suggested Lesson Videos

For further understanding of nutrient deficiency and excess disorders, students can search on YouTube for:

• nutrient deficiency disorders food and nutrition SS1
• nutrient excess disorders food and nutrition SS1