Food, nutrition and health Revision Guide
Topic Overview
This topic explores the relationship between diet and health, focusing on how the nutrients we consume affect our bodies. You'll learn about the major nutrient groups—carbohydrates, proteins, fats, vitamins, minerals, fibre, and water—and their specific functions, sources, and the consequences of deficiency or excess. Understanding this is essential for making informed food choices and for designing balanced diets for different life stages and lifestyles.
In the AQA GCSE Food Preparation and Nutrition course, 'Food, nutrition and health' forms the foundation for all other topics. It links directly to food science (how nutrients behave during cooking), food safety (why certain nutrients spoil), and food choice (how nutritional needs vary). Mastering this content is crucial for both the written exam and the non-exam assessment (NEA), where you'll need to justify your menu choices based on nutritional principles.
Beyond exams, this knowledge empowers you to evaluate dietary claims in the media, plan healthier meals, and understand public health issues like obesity, type 2 diabetes, and malnutrition. It's not just about memorising facts—it's about applying them to real-world scenarios, such as adapting a recipe to be more nutritious or advising someone with a specific health condition.
Key Concepts
Core ideas you must understand for this topic
- →Macronutrients (carbohydrates, proteins, fats) provide energy and are needed in large amounts; micronutrients (vitamins, minerals) are needed in small amounts but are vital for specific functions.
- →Energy balance: energy intake (from food) must equal energy expenditure (basal metabolic rate + physical activity) to maintain a healthy weight. Positive balance leads to weight gain; negative balance leads to weight loss.
- →Dietary Reference Values (DRVs) like Estimated Average Requirements (EAR) and Reference Nutrient Intakes (RNI) are guidelines for healthy populations, not individuals.
- →Deficiency diseases: e.g., scurvy (vitamin C deficiency), rickets (vitamin D deficiency), iron-deficiency anaemia. Excess can also cause problems, e.g., too much saturated fat increases heart disease risk.
- →The Eatwell Guide shows the proportions of different food groups needed for a balanced diet, and how to apply it to meals and snacks.
What You Need to Demonstrate
Key skills and knowledge for this topic
- Functions of protein, fats, and carbohydrates in the body.
- Identification of main food sources for each macronutrient.
- Consequences of deficiency and excess intake for each macronutrient.
- Understanding of Dietary Reference Values (DRVs) related to macronutrients.
- Distinction between high and low biological value proteins.
- Concept of protein complementation.
- Distinction between saturated and unsaturated (monounsaturated and polyunsaturated) fats.
- Distinction between starch (polysaccharides) and sugars (monosaccharides/disaccharides).
Marking Points
Key points examiners look for in your answers
- Functions of protein, fats, and carbohydrates in the body.
- Identification of main food sources for each macronutrient.
- Consequences of deficiency and excess intake for each macronutrient.
- Understanding of Dietary Reference Values (DRVs) related to macronutrients.
- Distinction between high and low biological value proteins.
- Concept of protein complementation.
- Distinction between saturated and unsaturated (monounsaturated and polyunsaturated) fats.
- Distinction between starch (polysaccharides) and sugars (monosaccharides/disaccharides).
- Role of dietary fibre.
Examiner Tips
Expert advice for maximising your marks
- 💡Use specific examples of food sources when answering questions about macronutrient intake.
- 💡Ensure you can explain the health implications of both deficiency and excess for each macronutrient.
- 💡Be prepared to apply knowledge of macronutrients to modify recipes for specific dietary needs, such as vegetarianism.
- 💡Link the theoretical knowledge of macronutrients to the practical skills of food preparation, such as using protein alternatives or reducing fat content.
- 💡Use specific nutrient names and functions, not just general terms. For example, instead of 'vitamins are important', say 'vitamin C is needed for collagen production and wound healing, and its deficiency causes scurvy.'
- 💡When discussing dietary guidelines, always link to the Eatwell Guide or DRVs. Show you understand they are population-based, not rigid rules for individuals.
- 💡In longer-answer questions, structure your response: state the nutrient, its function, a food source, and the consequence of imbalance. Use connectives like 'therefore' and 'because' to show reasoning.
Common Mistakes
Pitfalls to avoid in your exam answers
- Confusing high biological value (HBV) and low biological value (LBV) protein sources.
- Failing to correctly identify the difference between saturated and unsaturated fats.
- Misunderstanding the role of protein complementation in vegetarian diets.
- Confusing the different types of carbohydrates (simple sugars vs complex starches).
- Misconception: 'All fats are bad for you.' Correction: Unsaturated fats (e.g., from olive oil, nuts, fish) are essential for health and can reduce heart disease risk. It's saturated and trans fats that should be limited.
- Misconception: 'Carbohydrates make you fat.' Correction: Carbohydrates are the body's preferred energy source. Weight gain occurs from excess calories overall, not specifically from carbs. Wholegrain carbs also provide fibre and nutrients.
- Misconception: 'You need to drink 8 glasses of water a day.' Correction: Fluid needs vary by age, activity, and climate. Water from food and other drinks counts too. The key is to drink when thirsty and ensure urine is pale yellow.
Frequently Asked Questions
Common questions students ask about this topic