Success Criteria

1. Describe the different food nutrients.

2. Test a given foodstuff for starch, protein, reducing sugar, and lipids.

3. Investigate common sources of food nutrients in the community.

4. Plan a balanced diet.

5. Describe deficiency diseases.

Overview of Nutrition

• Nutrition: The study of food and eating habits.

• Nutrients: Chemical substances in food that affect growth and development.

Classes of Nutrients

1. Carbohydrates

   • Composed of carbon, hydrogen, and oxygen.

   • Types:

     • Monosaccharides: Simple sugars (e.g., glucose, fructose).

     • Disaccharides: Double sugars (e.g., sucrose, maltose).

     • Polysaccharides: Long chains (e.g., starch, glycogen).

   • Functions: Energy production, tissue building.

2. Proteins

   • Composed of carbon, hydrogen, oxygen, and nitrogen.

   • Made of amino acids.

   • Functions: Tissue repair, body building, antibody formation.

3. Lipids

   • Composed of carbon, hydrogen, and oxygen; fats (solid) and oils (liquid).

   • Sources:

     • Fats: Margarine, butter, lard.

     • Oils: Groundnut oil, cottonseed oil, sunflower oil.

   • Functions: High energy production, insulation, vitamin D production, cell tissue building.

4. Vitamins

   • Needed in small amounts but essential.

   • Types:

     • Water-soluble (e.g., Vitamin C).

     • Fat-soluble (e.g., Vitamins A, D, E, K).

   • Destruction: High heat, light, chemicals.

5. Mineral Salts

   • Needed in small amounts; obtained from food.

   • Key minerals: Iodine, calcium, iron, fluorides.

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6. Water

   • Composed of hydrogen and oxygen.

   • Functions: Aids digestion, absorption, blood volume maintenance, joint lubrication, temperature regulation.

Macro and Micro Elements

• Macro Elements: Needed in large amounts (carbohydrates, proteins, lipids, water).

• Micro Nutrients: Needed in small amounts (vitamins, mineral salts).

Factors Affecting Food Choice

1. Tradition: Cultural food preferences (e.g., Nsima).

2. Affordability: Budget constraints affect food choices.

3. Convenience: Availability of seasonal foods.

4. Religious Beliefs: Dietary restrictions (e.g., avoiding pork).

5. Habit: Established eating patterns (e.g., typical breakfast items).

Balanced Diet

• Definition: A diet containing all six food substances in appropriate amounts.

• Components:

  1. Carbohydrates

  2. Proteins

  3. Lipids

  4. Vitamins

  5. Mineral salts

  6. Water

Examples of a Balanced Diet

1. Breakfast:

   • Porridge with whole grain maize flour, groundnut powder, iodized salt, fruit, water.

   • Tea with milk, sugar, potatoes/bread with margarine, fruit.

   • Nsima with green vegetables, groundnut powder, fruit, water.

2. Lunch:

   • Sweet potatoes with groundnuts, fruit, water.

   • Nsima with green vegetables, groundnut powder, fruit, water.

   • Rice with milk, margarine, fruit, vegetables, water.

3. Supper:

   • Sweet potatoes with groundnuts, fruit, water.

   • Nsima with green vegetables, groundnut powder, fruit, water.

   • Rice with milk, margarine, fruit, vegetables, water.

Deficiency Diseases

• Occur when the diet is unbalanced, leading to insufficient intake of necessary nutrients.

Common Deficiency Diseases in Malawi

1. Kwashiorkor

   • Cause: Lack of protein in the diet.

   • Signs and Symptoms:

     • Weight loss

     • Oedema (swelling)

     • Diarrhea

     • Stunted growth

     • Pale, soft, straight hair

   • Prevention: Balanced diet.

2. Marasmus

   • Causes:

     • Starvation

     • Shortage of carbohydrates.

   • Signs and Symptoms:

     • Thin body

     • Monkey-like facial appearance

     • Wasted muscles

     • Stunted growth

     • Good appetite.

   • Prevention and Treatment: Balanced diet.

3. Goiter

   • Cause: Lack of iodine.

   • Signs and Symptoms: Swelling of the thyroid glands.

   • Prevention and Treatment:

     • Use iodized salt in the diet.

     • Surgical removal of the gland if necessary.

4. Anaemia

   • Cause: Lack of iron in the diet.

   • Signs and Symptoms:

     • Body weakness

     • Heart palpitations

     • Oedema

     • Paleness of mucous membranes.

   • Prevention and Treatment:

     • Use of iron tablets.

     • Eat iron-rich foods (e.g., eggs, liver, green vegetables).

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5. Pellagra

   • Cause: Lack of vitamin B2 (Riboflavin).

   • Signs and Symptoms:

     • Cracking and scaling of the skin

     • Diarrhea

     • Nervousness

     • Dizziness.

   • Prevention and Treatment: Diet rich in vitamin B2; use vitamin B complex tablets or powder.

6. Rickets

   • Cause: Lack of vitamin D.

   • Signs and Symptoms:

     • Soft bones

     • Deformed legs

     • Enlarged, tender joints

     • Bony chest

     • Poorly formed teeth.

   • Prevention and Treatment: Include foods containing vitamin D in the diet.

7. Night Blindness

   • Cause: Lack of vitamin A.

   • Signs and Symptoms: Loss of shine in the whites of the eyes.

   • Prevention and Control: Diet rich in yellow and red fruits, and green vegetables.

8. Scurvy

   • Cause: Lack of vitamin C.

   • Signs and Symptoms:

     • Gum bleeding

     • Painful joints

     • Lowered immunity

     • Loss of energy.

   • Prevention and Treatment: Diet including citrus fruits and green vegetables.

General Causes of Deficiency Diseases

• Lack of nutrients in the diet

• Body’s inability to absorb nutrients

• Illiteracy

• Poverty

• Poor food preparation (e.g., overcooking)

Effects of Deficiency Diseases

• Stunted growth

• Blindness

• Increased susceptibility to infections

• Deformities

• Reduced community participation

• Loss of resources due to treatment costs

• Retarded community and national development

Obesity

• Definition: A body disorder resulting in weight gain from overeating.

• Signs and Symptoms:

  • Overweight

  • Difficulty breathing

  • Increased body fat.

• Prevention and Treatment:

  • Regular exercise

  • Reduced food energy intake.

Treatment for Deficiency Diseases

• Providing food rich in required nutrients

• Using vitamin and mineral supplements

• Eating fortified foods.

Vitamins: Sources, Functions, and Deficiencies

• Vitamin A

  • Source: Green vegetables, fruits, milk, eggs

  • Function: Proper vision, immunity

  • Deficiency: Night blindness, drying of eyes, reduced immunity

• Vitamin B1

  • Source: Green vegetables, fruits, milk, mushrooms

  • Function: Cell respiration, nervous system maintenance, normal heart function

  • Deficiency: Beriberi, oedema, paralysis, memory loss

• Vitamin B2

  • Source: Green vegetables, milk, cereals, bread, meat

  • Function: Aids in respiration

  • Deficiency: Skin issues, fatigue

• Vitamin C

  • Source: Green vegetables, fruits

  • Function: Immunity, absorption of iron, strengthens blood vessel walls

  • Deficiency: Scurvy, rough skin, painful joints, hysteria

• Vitamin D

  • Source: Green vegetables, milk, liver, sunlight

  • Function: Absorption of calcium and phosphorus, strong bones

  • Deficiency: Rickets, head enlargement, weak bones