Food and Nutrition Basic 6 Basic Technology Lesson Note

LEARNING OBJECTIVES By the end of the lesson, pupils should be able to:

1. Discuss the concept of food and nutrition
2. Mention sources of food nutrients
3. Highlight the nutritional deficiency diseases
4. Investigate the characteristics of those deficiency diseases

CONCEPT OF FOOD AND NUTRITION

WHAT IS FOOD?

Food is any substance that is eaten or drunk by living organisms to provide energy, promote growth, repair worn-out tissues, and maintain good health.

Functions of Food:

1. Provides energy for daily activities
2. Promotes growth and development
3. Repairs damaged tissues
4. Protects the body from diseases
5. Regulates body processes
6. Maintains good health

WHAT IS NUTRITION?

Nutrition is the process by which the body takes in and uses food for growth, energy, repair, and maintenance of body tissues. It involves eating, digestion, absorption, and utilization of nutrients.

Stages of Nutrition:

1. Ingestion: Taking food into the mouth (eating/drinking)
2. Digestion: Breaking down food into smaller particles
3. Absorption: Nutrients pass into bloodstream
4. Assimilation: Nutrients used by body cells
5. Egestion: Removal of waste products

WHY WE NEED FOOD

1. Energy:

• For walking, running, playing, studying
• For breathing, heartbeat, blood circulation
• For maintaining body temperature
• Measured in calories

2. Growth:

• Children need food to grow taller
• Build muscles and bones
• Develop organs and tissues
• Replace worn-out cells

3. Repair:

• Heal wounds and injuries
• Replace damaged tissues
• Fix broken bones
• Recover from illness

4. Protection:

• Fight diseases and infections
• Strengthen immune system
• Build resistance against germs
• Maintain healthy organs

5. Regulation:

• Control body temperature
• Maintain water balance
• Regulate heartbeat
• Control digestion

GOOD NUTRITION vs POOR NUTRITION

Good Nutrition:

• Eating balanced diet
• Proper amounts of all nutrients
• Healthy, strong body
• Good growth and development
• Strong immune system
• Good school performance

Poor Nutrition (Malnutrition):

• Not eating enough food (undernutrition)
• Eating too much food (overnutrition/obesity)
• Not eating variety of foods
• Deficiency diseases
• Weak body and immune system
• Poor growth and development

CLASSES OF FOOD NUTRIENTS

There are SEVEN main classes of food nutrients that our bodies need:

1. CARBOHYDRATES

Function:

• Provide energy for body activities
• Main source of energy
• Fuel for brain and muscles

Types:

• Simple carbohydrates: Sugar, honey, sweets (quick energy)
• Complex carbohydrates: Rice, yam, bread (long-lasting energy)

Sources:

• Cereals: Rice, maize, wheat, millet, guinea corn, oats
• Roots and tubers: Yam, cassava, potatoes, cocoyam, sweet potato
• Others: Bread, pasta, noodles, sugar, honey, plantain, bananas

What happens if deficient:

• Lack of energy, weakness, tiredness
• Weight loss
• Cannot perform activities
• Body uses protein for energy instead of growth

What happens if excess:

• Converted to fat and stored
• Weight gain, obesity
• Health problems (diabetes)

2. PROTEINS

Function:

• Build and repair body tissues
• Promote growth (especially in children)
• Make enzymes and hormones
• Build muscles, skin, hair, nails
• Form antibodies to fight diseases
• Make new cells

Types:

• Animal protein: From animals (complete proteins – better quality)
• Plant protein: From plants (may lack some amino acids)

Sources:

Animal Sources:

• Meat (beef, chicken, goat, pork)
• Fish (mackerel, titus, catfish)
• Eggs
• Milk and dairy products (cheese, yogurt)
• Shrimp, crayfish

Plant Sources:

• Beans (black-eyed peas, kidney beans)
• Soya beans
• Groundnuts (peanuts)
• Melon (egusi)
• Lentils, peas

What happens if deficient:

• Kwashiorkor (severe protein deficiency)
• Marasmus (protein and energy deficiency)
• Poor growth, stunted development
• Weak muscles
• Wounds heal slowly
• Frequent infections

What happens if excess:

• Extra converted to fat
• Kidney problems
• Weight gain

3. FATS AND OILS

Function:

• Provide concentrated energy (more than carbohydrates)
• Keep body warm (insulation)
• Protect internal organs (cushioning)
• Help absorb vitamins A, D, E, K
• Make food tasty
• Store energy for future use

Types:

• Saturated fats: Solid at room temperature (butter, lard)
• Unsaturated fats: Liquid at room temperature (vegetable oils – healthier)

Sources:

• Palm oil, groundnut oil, coconut oil
• Butter, margarine
• Cheese, cream
• Fatty meat, fish oil
• Avocado, nuts
• Olive oil, soya oil

What happens if deficient:

• Lack of energy
• Cannot absorb some vitamins
• Dry skin
• Poor insulation (feel cold easily)

What happens if excess:

• Obesity (too much body fat)
• Heart disease
• High cholesterol
• Blocked blood vessels

4. VITAMINS

Vitamins are organic compounds needed in small amounts to keep the body healthy and functioning properly.

VITAMIN A (Retinol)

Functions:

• Good eyesight (especially at night)
• Healthy skin
• Healthy hair
• Fights infections
• Helps growth

Sources:

• Carrots, tomatoes
• Oranges, mangoes, pawpaw
• Red palm oil
• Liver, eggs
• Green leafy vegetables
• Yellow vegetables

Deficiency Disease: Night Blindness (Xerophthalmia)

• Cannot see well in dim light or at night
• Dry eyes
• Dry, scaly skin
• Frequent infections
• Poor growth in children

VITAMIN B COMPLEX (Several types: B1, B2, B3, B6, B12)

Functions:

• Release energy from food
• Healthy nervous system
• Form red blood cells
• Healthy skin and hair
• Proper digestion

Sources:

• Beans, peas
• Whole grains (brown rice, wheat)
• Meat, fish, eggs
• Milk, cheese
• Leafy vegetables
• Yeast, liver

Deficiency Disease: Beriberi (Lack of Vitamin B1)

• Weakness and tiredness
• Loss of appetite
• Numbness in hands and feet
• Difficulty walking
• Swollen legs
• Confusion, memory loss

VITAMIN C (Ascorbic Acid)

Functions:

• Healthy gums and teeth
• Heals wounds quickly
• Fights infections
• Helps absorb iron
• Healthy skin
• Strong blood vessels

Sources:

• Citrus fruits (oranges, lemons, lime, grapefruit)
• Tomatoes
• Guava
• Pineapple
• Mangoes
• Green vegetables (cabbage, lettuce)
• Peppers

Deficiency Disease: Scurvy

• Bleeding gums
• Loose teeth, teeth fall out
• Wounds heal slowly
• Skin bruises easily
• Weakness and tiredness
• Swollen, painful joints
• Rough, dry skin

VITAMIN D (Calciferol)

Functions:

• Helps body absorb calcium
• Builds strong bones and teeth
• Prevents bone diseases
• Helps muscles work properly

Sources:

• Sunlight (most important source – body makes it in skin)
• Egg yolk
• Fatty fish (mackerel, sardines)
• Liver
• Milk (fortified)
• Butter

Deficiency Disease: Rickets (in children)

• Soft, weak bones
• Bow legs or knock knees
• Curved spine
• Slow growth
• Weak muscles
• Bone pain
• Deformed chest

Osteomalacia (in adults)

• Soft bones
• Bone pain
• Muscle weakness

VITAMIN E

Functions:

• Protects cells from damage
• Healthy skin
• Healthy eyes
• Strong immune system
• Helps wounds heal

Sources:

• Vegetable oils
• Nuts and seeds
• Green leafy vegetables
• Whole grains
• Eggs

Deficiency:

• Rare, but can cause muscle weakness
• Poor coordination
• Vision problems

VITAMIN K

Functions:

• Blood clotting (stops bleeding)
• Healthy bones
• Wound healing

Sources:

• Green leafy vegetables (spinach, lettuce, cabbage)
• Liver
• Eggs
• Broccoli

Deficiency:

• Excessive bleeding
• Wounds don’t stop bleeding easily
• Easy bruising

5. MINERALS

Minerals are inorganic elements needed by the body for various functions.

CALCIUM

Functions:

• Builds strong bones and teeth
• Blood clotting
• Muscle contraction
• Nerve function
• Heart rhythm

Sources:

• Milk and dairy products
• Fish with bones (sardines)
• Green leafy vegetables
• Beans, soya beans
• Eggs, cheese

Deficiency:

• Rickets (in children)
• Osteoporosis (in adults – brittle bones)
• Weak teeth, tooth decay
• Muscle cramps
• Slow growth

IRON

Functions:

• Forms hemoglobin in red blood cells
• Carries oxygen in blood
• Prevents anemia
• Energy production

Sources:

• Red meat, liver
• Fish
• Beans, lentils
• Green leafy vegetables (spinach)
• Egg yolk
• Groundnuts

Deficiency Disease: Anemia

• Pale skin, lips, and tongue
• Weakness and extreme tiredness
• Dizziness, headaches
• Shortness of breath
• Fast heartbeat
• Cannot concentrate
• Cold hands and feet
• Frequent infections

IODINE

Functions:

• Thyroid gland function
• Produces thyroid hormones
• Controls metabolism
• Brain development
• Growth and development

Sources:

• Iodized salt (table salt)
• Seafood (fish, shrimp)
• Seaweed
• Eggs
• Dairy products

Deficiency Disease: Goitre

• Swollen neck (enlarged thyroid gland)
• Difficulty swallowing
• Coughing
• Weight gain
• Tiredness
• Slow thinking
• In severe cases: mental retardation (cretinism)

PHOSPHORUS

Functions:

• Works with calcium for strong bones and teeth
• Energy production
• Kidney function

Sources:

• Milk, cheese
• Meat, fish
• Beans, nuts
• Whole grains

SODIUM

Functions:

• Maintains fluid balance
• Nerve and muscle function
• Blood pressure regulation

Sources:

• Table salt
• Most foods naturally contain some sodium

Deficiency/Excess:

• Too little: muscle cramps, weakness
• Too much: high blood pressure

6. WATER

Functions:

• Most important nutrient (body is 60-70% water)
• Helps digestion
• Transports nutrients in blood
• Removes waste products (urine, sweat)
• Regulates body temperature
• Cushions organs and joints
• Helps chemical reactions in body

Sources:

• Drinking water
• Fruits (oranges, watermelon, pineapple)
• Vegetables (cucumber, lettuce, tomatoes)
• Soups, juices
• Milk

Amount Needed:

• Children: 6-8 glasses per day
• Adults: 8-10 glasses per day
• More in hot weather or during exercise

Deficiency: Dehydration

• Thirst
• Dry mouth and lips
• Dark yellow urine
• Tiredness, weakness
• Dizziness, headache
• Cannot concentrate
• Dry skin
• In severe cases: can be life-threatening

7. ROUGHAGE (DIETARY FIBER)

Definition: Roughage is the indigestible part of plant foods that helps move food through the digestive system.

Functions:

• Aids digestion
• Prevents constipation
• Helps food move through intestines
• Makes you feel full
• Prevents some diseases (colon cancer)
• Controls blood sugar
• Lowers cholesterol

Sources:

• Fruits (with skin): apples, pears, oranges
• Vegetables: cabbage, lettuce, carrots
• Whole grains: brown rice, whole wheat bread, oats
• Beans, lentils
• Nuts and seeds
• Corn, popcorn

Deficiency:

• Constipation (difficulty passing stool)
• Stomach pain
• Bloating
• Irregular bowel movements
• Increased risk of colon diseases

BALANCED DIET

A balanced diet is a diet that contains all the classes of food nutrients in the right proportions to maintain good health.

Components of Balanced Diet:

• Carbohydrates: 50-60%
• Proteins: 15-20%
• Fats: 20-30%
• Vitamins, minerals, water, roughage: Adequate amounts

Example of Balanced Meal:

• Breakfast: Bread (carbohydrate) + Egg (protein) + Orange juice (vitamin C) + Milk (calcium)
• Lunch: Rice (carbohydrate) + Fish stew (protein, fats) + Vegetables (vitamins, minerals, roughage) + Water
• Dinner: Yam (carbohydrate) + Bean sauce (protein) + Plantain + Vegetable salad + Water

TIPS FOR GOOD NUTRITION

1. Eat variety of foods daily
2. Include all food groups in every meal
3. Eat plenty of fruits and vegetables
4. Drink at least 6-8 glasses of water daily
5. Eat three meals a day (breakfast, lunch, dinner)
6. Don’t skip breakfast (most important meal)
7. Limit sugary foods and drinks
8. Eat moderate portions (not too much)
9. Wash fruits and vegetables before eating
10. Practice good hygiene when handling food

EVALUATION

1. Define food and nutrition
2. List the seven classes of food nutrients
3. What disease is caused by lack of Vitamin C?
4. Name three sources of protein
5. What are the functions of carbohydrates in the body?

MULTIPLE CHOICE QUESTIONS

1. How many classes of food nutrients are there? 

1. a) Five
2. b) Six
3. c) Seven
4. d) Eight

1. Which nutrient provides the most energy? 

1. a) Proteins
2. b) Vitamins
3. c) Carbohydrates and Fats
4. d) Water

1. Protein is needed mainly for ________ 

1. a) Energy only
2. b) Growth and repair
3. c) Warmth
4. d) Digestion only

1. Scurvy is caused by lack of ________ 

1. a) Vitamin A
2. b) Vitamin B
3. c) Vitamin C
4. d) Vitamin D

1. Which nutrient helps us see well at night? 

1. a) Vitamin A
2. b) Calcium
3. c) Iron
4. d) Protein

1. Rickets is caused by lack of ________ 

1. a) Vitamin A
2. b) Vitamin C
3. c) Vitamin D and Calcium
4. d) Iron

1. Beans are a good source of ________ 

1. a) Vitamin C
2. b) Protein
3. c) Calcium only
4. d) Water only

1. Anemia is caused by lack of ________ 

1. a) Calcium
2. b) Iodine
3. c) Iron
4. d) Vitamin A

1. Goitre is caused by lack of ________ 

1. a) Iron
2. b) Calcium
3. c) Iodine
4. d) Vitamin C

1. Which nutrient helps in digestion? 

1. a) Fats
2. b) Proteins
3. c) Roughage
4. d) Carbohydrates

1. Kwashiorkor is caused by lack of ________ 

1. a) Carbohydrates
2. b) Protein
3. c) Water
4. d) Vitamins only

1. Water is needed for _______