Lesson Notes By Weeks and Term v3 - Senior Secondary 1
Basic food nutrients
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Basic food nutrients
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Subject: Foods & Nutrition
Class: Senior Secondary 1
Term: 3rd Term
Week: 1
Theme: Nutrition And Health
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Students should be ableto:Identify the variousfoods in the locality. List the variousfood nutrients. Classify the variouslocal foodsaccording to the irnutrient quality and function.
from shock and injury.
4. Carries fat-soluble vitamins (A, D, E, K) into the body and aids their absorption.
5. Adds flavour and palatability to food.
Nigerian Food Sources: Oils: _Palm oil, Groundnut oil, Soybean oil, Coconut oil, Melon seed oil._ Foods: _Avocado pear, Groundnuts, Melon seeds (egusi), Cashew nuts, Fatty fish (e.g., mackerel – titus), Red meat with visible fat._ Deficiency Symptoms: Dry skin, hair loss, reduced growth, vulnerability to cold, impaired absorption of fat-soluble vitamins.
D. Vitamins (Protective/Regulatory Foods)
Composition: Organic compounds required in small quantities for various metabolic functions. They do not provide energy.
Types: Fat-soluble Vitamins (A, D, E, K): Stored in the body's fatty tissues. Water-soluble Vitamins (B-complex, C): Not stored in the body and must be consumed regularly.
General Functions: Act as co-enzymes and regulators of body processes, essential for growth, vision, immune function, and overall health.
Nigerian Food Sources (Examples): Vitamin A: Carrots, Sweet potatoes, Palm oil, Green leafy vegetables (ugu, ewedu, bitter leaf), Eggs, Liver. (Crucial for vision, immune function).
Vitamin B-complex: Whole grains, Legumes (beans), Meat, Fish, Eggs, Green leafy vegetables. (Essential for energy metabolism, nerve function).
Vitamin C: Oranges, Guava, Tomatoes, Mango, Papaya, Bell peppers. (Important for immunity, collagen formation, iron absorption).
Vitamin D: Sunlight exposure, Fatty fish, Fortified milk. (Bone health).
Vitamin E: Vegetable oils, Nuts, Green leafy vegetables. (Antioxidant).
Vitamin K: Green leafy vegetables. (Blood clotting).
Deficiency Symptoms: Vitamin A: Night blindness, impaired immunity.
B-complex: Beriberi (Thiamine), Pellagra (Niacin), Anaemia (Folic acid, B12), fatigue.
Vitamin C: Scurvy (bleeding gums, poor wound healing).
Vitamin D: Rickets in children, Osteomalacia in adults.
E. Minerals (Protective/Regulatory Foods)
Composition: Inorganic elements required in small quantities. They do not provide energy.
Types: Major Minerals: Calcium, Phosphorus, Sodium, Potassium, Chloride, Magnesium, Sulfur (needed in larger amounts).
Trace Minerals: Iron, Zinc, Iodine, Selenium, Copper, Manganese, Fluoride (needed in smaller amounts).
General Functions: Building strong bones and teeth, fluid balance, nerve function, muscle contraction, blood formation, and many enzyme systems.
Nigerian Food Sources (Examples): Calcium: Milk, Green leafy vegetables (efo, ugu), Sardines (with bones), Sesame seeds. (Bone health, nerve function).
Iron: Red meat, Liver, Beans, Green leafy vegetables, Fortified cereals. (Blood formation, oxygen transport – preventing anaemia).
Iodine: Iodized salt, Seafood (fish, prawns). (Thyroid function, preventing goitre).
Sodium & Potassium: Table salt, Fruits (banana, oranges), Vegetables. (Fluid balance, nerve and muscle function).
Zinc: Meat, Fish, Beans, Nuts. (Immune function, growth).
Deficiency Symptoms: Iron: Anaemia (fatigue, pale skin).
Calcium: Weak bones, osteoporosis.
Iodine: Goitre (enlarged thyroid gland), developmental issues.
F. Water (Regulatory and Protective Food)
Composition: H2O (Hydrogen and Oxygen).
Functions:
1. Main component of cells, tissues, and organs.
2. Acts as a solvent for nutrients and waste products.
3. Transports nutrients to cells and carries waste products away.
4. Regulates body temperature through perspiration.
5. Lubricates joints and protects organs.
6. Essential for chemical reactions in the body.
Nigerian Food Sources: Drinking water, Fruits (watermelon, orange), Vegetables (cucumber, lettuce), Soups, Juices.
Deficiency Symptoms: Dehydration (thirst, dizziness, fatigue), reduced physical and mental performance, dry skin, constipation. 2.
3. Classifying Local Foods by Nutrient Quality and Function To classify local foods, one identifies the predominant nutrient or the most significant contribution a food makes to the diet. Worked
Example: Consider a common Nigerian meal: Yam and Egusi soup with some fish and _ugu_ leaves.
1. Yam: Primarily Carbohydrate (starch). Its function is to provide energy.
2. Egusi (Melon Seeds): Primarily Protein and Fats & Oils. Its function is body-building, repair, and energy.
3. Fish: Primarily Protein (animal source). Its function is body-building and repair.
4. Ugu (Fluted Pumpkin Leaves): Primarily Vitamins (e.g., Vitamin A, C) and Minerals (e.g., Iron, Calcium), and Fibre. Its function is protection, regulation of body processes, and aiding digestion.
5. Palm Oil (in soup): Primarily Fats & Oils (saturated and unsaturated). Its function is energy, absorption of fat-soluble vitamins, and protection.
Therefore, a teacher would guide students to categorize foods by their main nutrient content and the This section provides an in-depth explanation of food nutrients, their types, functions, and common Nigerian food sources. 2.
1. Definition of Food and Food Nutrients Food: Any edible substance that, when eaten, provides nourishment, energy, and contributes to the growth, repair, and maintenance of the body. In Nigeria, examples include _garri, pounded yam, rice, beans, fish, vegetables, fruits._ Nutrients: Chemical substances found in food that are essential for the body's growth, maintenance, and repair, and for the efficient functioning of all body processes. These are broadly categorized into macronutrients (needed in large amounts) and micronutrients (needed in small amounts). 2.
2. Classification and Explanation of Basic Food Nutrients There are six main classes of food nutrients: Carbohydrates, Proteins, Fats & Oils, Vitamins, Minerals, and Water.
A. Carbohydrates (Energy-Giving Foods)
Composition: Composed of Carbon (C), Hydrogen (H), and Oxygen (O).
Types: Sugars (Simple Carbohydrates): Readily absorbed, provide quick energy.
Examples: Glucose, Fructose (in fruits), Sucrose (table sugar, found in sugarcane).
Starches (Complex Carbohydrates): Digested slowly, provide sustained energy.
Examples: Found in cereals, tubers, legumes.
Fibre (Non-starch Polysaccharides): Indigestible by humans, but crucial for digestive health, preventing constipation, and regulating blood sugar.
Examples: Found in whole grains, fruits, vegetables.
Functions:
1. Primary source of energy for all bodily activities (movement, breathing, thinking).
2. Spares protein from being used for energy, allowing it to perform its primary function.
3. Dietary fibre aids digestion, prevents constipation, and helps regulate blood sugar and cholesterol levels.
Nigerian Food Sources: Staples: _Yam, Cassava (garri, fufu, tapioca), Rice, Maize (corn), Millet, Sorghum, Plantain, Sweet potatoes._ Sugars: Honey, Sugarcane, Ripe fruits (mango, banana, pineapple).
Deficiency Symptoms: Fatigue, weight loss, lack of energy, reduced physical and mental performance.
B. Proteins (Body-Building/Repair Foods)
Composition: Complex organic compounds composed of amino acids, containing Carbon (C), Hydrogen (H), Oxygen (O), Nitrogen (N), and sometimes Sulfur (S).
Types: Complete Proteins: Contain all essential amino acids (those the body cannot produce). Primarily found in animal sources.
Incomplete Proteins: Lack one or more essential amino acids. Primarily found in plant sources. Combining different plant proteins (e.g., beans and rice) can provide complete protein.
Functions:
1. Essential for growth and repair of body tissues (muscles, skin, hair, nails).
2. Formation of enzymes, hormones, and antibodies, which are vital for metabolic processes and immunity.
3. Secondary source of energy when carbohydrates and fats are insufficient.
4. Maintains fluid balance and pH balance in the body.
Nigerian Food Sources: Animal Proteins: _Fish (tilapia, catfish, mackerel – titus, sarda), Meat (beef, goat meat, chicken), Eggs, Milk (fresh milk, nunu), Dairy products (yoghurt, wara - local cheese)._ Plant Proteins: _Beans (cowpea), Groundnuts (peanuts), Soybeans, Melon seeds (egusi), African oil bean seed (ugba), Pumpkin seeds (ugu)._ Deficiency Symptoms: Stunted growth in children, muscle wasting, oedema (swelling, characteristic of Kwashiorkor), poor wound healing, weakened immune system.
C. Fats & Oils (Energy-Giving and Protective Foods)
Composition: Composed of Carbon (C), Hydrogen (H), and Oxygen (O), but with a higher proportion of H and lower O than carbohydrates.
Types: Saturated Fats: Solid at room temperature (e.g., butter, lard, coconut oil, palm oil). Generally consumed in moderation.
Unsaturated Fats: Liquid at room temperature (e.g., vegetable oils like groundnut oil, sunflower oil, olive oil).
Monounsaturated fats (MUFA): Olive oil, groundnut oil.
Polyunsaturated fats (PUFA): Sunflower oil, corn oil, fatty fish.
Functions:
1. Concentrated source of energy (more than twice the energy per gram compared to carbohydrates or protein).
2. Insulates the body and helps maintain body temperature.
3. Protects vital organs from shock and injury.
4. Carries fat-soluble vitamins (A, D, E, K) into the body and aids their absorption.
5. Adds flavour and palatability to food.
Nigerian Food Sources: Oils: _Palm oil, Groundnut oil, Soybean oil, Coconut oil, Melon seed oil._ Foods: _Avocado pear, Groundnuts, Melon seeds (egusi), Cashew nuts, Fatty fish (e.g., mackerel – titus), Red meat with visible fat._ Deficiency Symptoms: Dry skin, hair loss, reduced growth, vulnerability to cold, impaired absorption of fat-soluble vitamins.
D. Vitamins (Protective/Regulatory Foods) * Composition: Organic compounds required in small Primarily Protein and Fats & Oils. Its function is body-building, repair, and energy.
3. Fish: Primarily Protein (animal source). Its function is body-building and repair.
4. Ugu (Fluted Pumpkin Leaves): Primarily Vitamins (e.g., Vitamin A, C) and Minerals (e.g., Iron, Calcium), and Fibre. Its function is protection, regulation of body processes, and aiding digestion.
5. Palm Oil (in soup): Primarily Fats & Oils (saturated and unsaturated). Its function is energy, absorption of fat-soluble vitamins, and protection.
Therefore, a teacher would guide students to categorize foods by their main nutrient content and the corresponding role it plays in the body. This section outlines the step-by-step activities for the teacher and students to achieve the lesson objectives.
Phase 1: Introduction (10 minutes)
Teacher Activity: Begins by asking students to name some of the foods they commonly eat at home or find in their local market. The teacher lists these on the board.
Student Activity: Students actively participate, naming a variety of local foods (e.g., yam, rice, beans, fish, mango, _garri_, plantain, _akara_, groundnut, _ewedu_).
Phase 2: Identifying Various Local Foods (Objective 1) (15 minutes)
Teacher Activity: Organizes students into small groups (if feasible) or facilitates a whole-class discussion. Guides students to identify and categorize the listed foods further based on common knowledge (e.g., "foods that give strength," "foods that help us grow"). The teacher can use visual aids (pictures of local foods) or real food items if available.
Student Activity: In groups or as a class, students discuss and list more local foods, perhaps categorizing them informally based on perceived benefits. They might share where these foods are sourced (farm, market).
Phase 3: Listing the Various Food Nutrients (Objective 2) (20 minutes)
Teacher Activity: Introduces the concept of "food nutrients" as the components of food that the body uses. Presents the six main classes of food nutrients: Carbohydrates, Proteins, Fats & Oils, Vitamins, Minerals, and Water. Explains each nutrient class briefly, focusing on their general roles (e.g., "energy givers," "body builders," "protective foods"). Writes the names of the nutrient classes on the board.
Student Activity: Students listen, take notes, and ask clarifying questions about the nutrient classes. They attempt to recall which of the previously listed local foods might belong to which nutrient group, based on the teacher's brief explanation.
Phase 4: Classifying Local Foods According to Their Nutrient Quality and Function (Objective 3) (30 minutes)
Teacher Activity: Deepens the explanation for each nutrient class, detailing specific functions and providing numerous examples of local Nigerian food sources for each. For Carbohydrates, explain types (starch, sugar, fibre) with examples like _yam, garri, rice, plantain, sugarcane_.
Functions: Energy. For Proteins, explain animal vs. plant sources, complete/incomplete proteins with examples like _fish, beans, egusi, meat_.
Functions: Growth, repair. For Fats & Oils, explain sources like _palm oil, groundnut oil, avocado_.
Functions: Concentrated energy, protection. For Vitamins, mention categories (fat/water soluble) and key vitamins (A, B, C, D, E, K) with examples like _carrots, green leafy vegetables, oranges, liver_.
Functions: Protection, regulation. For Minerals, mention key minerals (Iron, Calcium, Iodine, Zinc) with examples like _red meat, milk, iodized salt, leafy greens_.
Functions: Bone formation, blood formation. For Water, mention its importance and sources.
Functions: Hydration, transport.
Teacher Activity: Guides students in a practical classification exercise. Selects a few common Nigerian dishes (e.g., _Jollof Rice with chicken, Egusi Soup with Pounded Yam, Akara and pap_). Asks students to break down each dish into its main ingredients and identify the primary nutrient class and function of each ingredient. Writes a table on the board for this classification.
Example Table: | Local Food Item | Primary Nutrient Class | Primary Function | | :-------------- | :--------------------- | :--------------- | | Yam | Carbohydrates | Energy | | Fish | Proteins | Body-building | | Palm Oil | Fats & Oils | Energy, Protection | | _Ugu_ Leaves | Vitamins, Minerals, Fibre | Protection, Regulation | Student Activity: Students actively participate in the classification, contributing local food examples and their primary nutrient classes and functions. They fill out the table in their notebooks, applying the knowledge gained. They may share personal examples of meals and their components.
Phase 5: Conclusion (5 minutes)
Teacher Activity: Summarizes the key learning points, reiterating the six classes of nutrients and their importance for health. Assigns a brief take-home activity or independent practice.
Student Activity: Students recap the main nutrient classes and their functions.
Consider a common Nigerian meal: Yam and Egusi soup with some fish and _ugu_ leaves.
Yam: Primarily Carbohydrate (starch). Its function is to provide energy.
Egusi (Melon Seeds): Primarily Protein and Fats & Oils. Its function is body-building, repair, and energy.
Fish: Primarily Protein (animal source). Its function is body-building and repair.
Ugu (Fluted Pumpkin Leaves): Primarily Vitamins (e.g., Vitamin A, C) and Minerals (e.g., Iron, Calcium), and Fibre. Its function is protection, regulation of body processes, and aiding digestion.
Palm Oil (in soup): Primarily Fats & Oils (saturated and unsaturated). Its function is energy, absorption of fat-soluble vitamins, and protection.
Therefore, a teacher would guide students to categorize foods by their main nutrient content and the corresponding role it plays in the body.
Teaching and Learning Activities
This section outlines the step-by-step activities for the teacher and students to achieve the lesson objectives.
Phase 1: Introduction (10 minutes)
This topic has profound relevance to daily life in Nigeria, offering practical applications that students can immediately use.
Promoting Balanced Diets in Households: Application: Students can apply their knowledge to plan more balanced meals for their families, ensuring a mix of energy-giving, body-building, and protective foods using readily available local ingredients. For example, instead of just _garri_ (carbohydrate), they can suggest adding _egusi_ soup (protein, fats, vitamins, minerals) and fish to make a more complete meal. This helps combat widespread malnutrition, especially in children, and non-communicable diseases related to poor diet in adults.
Local Context: Addressing Kwashiorkor (protein deficiency) by encouraging consumption of beans, groundnuts, or affordable fish, and Vitamin A deficiency by promoting palm oil, carrots, and green leafy vegetables. Making Informed Food Choices at Markets and Eateries: Application: When shopping at local markets (Eko, Ogbete, Mile 12) or eating at local food stalls, students can consciously identify the nutrient components of the foods they choose. This empowers them to select nutritious options, especially when on a budget, and avoid excessive consumption of unhealthy fats or sugars common in processed snacks.
Local Context: Opting for a plate of _rice and beans_ with vegetables over just _fried plantain_ or selecting fruits like mangoes and oranges for snacks instead of sugary drinks. Community Health and Agricultural Practices: Application: Understanding nutrient needs can influence community-level initiatives. For instance, local farmers can be encouraged to cultivate a diversity of crops that address specific nutrient gaps in the community. Knowledge of nutrients can also inform community health campaigns on infant feeding or maternal nutrition.
Local Context: Promoting the cultivation of iron-rich _ugu_ leaves, protein-rich cowpeas, or vitamin A-rich sweet potatoes in local gardens can contribute to food security and improved public health outcomes.