Describe what is meant by a balanced diet and why it is important.

7.1 Human Nutrition – Diet

What is a Balanced Diet?

A balanced diet is like a well‑planned road trip for your body. 🚗💨 It includes the right mix of carbohydrates, proteins, fats, vitamins, and minerals so that every organ gets the fuel and building blocks it needs. Think of it as a colourful plate: half fruits & vegetables, a quarter lean protein, and a quarter whole grains. This mix keeps your energy steady, your muscles strong, and your immune system ready for action.

Why is it Important?

A balanced diet:

• Provides the energy needed for daily activities – $E = 4 \text{ kcal g}^{-1}$ for carbs, $E = 4 \text{ kcal g}^{-1}$ for proteins, and $E = 9 \text{ kcal g}^{-1}$ for fats.
• Builds and repairs tissues (protein & amino acids).
• Regulates body functions through vitamins and minerals.
• Supports a healthy gut microbiome and immune defence.
• Reduces the risk of chronic diseases such as obesity, type 2 diabetes, and heart disease.

Key Nutrients & Food Groups

Exam Tips

1. Use the “Food Plate” analogy – it’s a memorable way to explain the 50 % fruits & veg, 25 % protein, 25 % grains split.
2. Remember the energy values for macronutrients: $4 \text{ kcal g}^{-1}$ for carbs & proteins, $9 \text{ kcal g}^{-1}$ for fats.
3. When asked why a balanced diet is important, list at least four benefits (energy, growth, immunity, disease prevention).
4. Use examples from the food groups table to support your answer.
5. Show understanding of micronutrients by linking vitamins/minerals to specific functions (e.g., vitamin C for collagen, iron for haemoglobin).
6. Practice diagram drawing – sketch a simple plate with labels to illustrate proportions.