Macronutrients (Junior Cert Home Economics): Revision Notes

Carbohydrates

Composition of Carbohydrates

• Made up of three elements: Carbon (C)

Hydrogen (H)

Oxygen (O)

• Through photosynthesis, plants use sunlight and carbon dioxide to produce carbohydrates, which we consume.

Structure of Carbohydrates

• Carbohydrates can exist as:

  • Simple sugars (e.g., glucose).

    

  • Starch (formed by long chains of simple sugars).

    

• During digestion, starch is broken down into simple sugars for energy.

Classification of Carbohydrates

Sugar: Found in foods like table sugar, honey, jam, cakes, and biscuits.

Starch: Found in cereals (wheat, rice), bread, pasta, flour, and potatoes.

Dietary Fibre (Roughage): Found in whole cereals, wholemeal bread, fruit, and vegetables (especially with skins).

Functions of Carbohydrates

• Provide most of the body's heat and energy.
• Excess carbohydrates are stored as fat (adipose tissue) to insulate the body.
• Dietary fibre aids digestion, prevents constipation, and reduces the risk of bowel diseases.

Sugar: What to Know

• High-sugar foods (e.g., cakes, biscuits, fizzy drinks) are empty calorie foods, providing energy but few nutrients.
• Hidden sugars are found in products like ketchup or ready-made sauces; always check labels.

Reducing Sugar Intake

• Replace sugary snacks with nuts and fresh fruit.
• Avoid sugary drinks; drink water instead.
• Avoid high-sugar foods like cakes and biscuits.
• Use artificial sweeteners for baking or hot drinks.
• Remember, you can check nutritional labels on food for sugar content.

Dietary Fibre

• What it Does: Fibre absorbs water, bulks waste, and helps it pass through the digestive system, aiding in regular bowel movements.

• Sources: High-fibre cereals, wholemeal bread, fruit and vegetables (with skins), nuts, dried fruits like raisins or prunes.

Increasing Fibre in the Diet

• Choose wholegrain options, e.g., brown bread or pasta, instead of white.
• Eat more fruit and vegetables with their skins.
• Include nuts or dried fruits in meals or snacks.

Reference Intake for Carbohydrates

• Fibre: Recommended intake is 25–35 g per day.
• On average, people in Ireland consume only 15–20 g, with only 20% meeting the recommended intake.

Key Takeaway

Carbohydrates are essential for energy and digestion. Focus on whole grains and high-fibre foods while reducing sugar intake to improve health and energy levels. Balancing your carbohydrate sources helps maintain optimal health!