Unit 3: Food in Daily Life - Science, Health and Consumer Choices
What you must understand
Unit 3 examines the science behind food and health and the way consumers make choices. You need to understand digestion and absorption, the glycaemic index, energy balance, and the relationship between diet and diet-related conditions such as obesity, type 2 diabetes, cardiovascular disease and dental caries. Know the Australian Dietary Guidelines and the Australian Guide to Healthy Eating as tools for assessing diets, and be able to analyse a diet against them using evidence.
You also need the consumer side: food labelling requirements (nutrition information panel, ingredient list, health claims vs nutrition content claims), food standards and regulation, and the influences on food purchasing such as price, marketing, convenience, culture and health beliefs. Be able to evaluate a food product using its label and explain why a claim may be misleading.
Traps in questions
- Treating the glycaemic index as a simple "good/bad" ranking; it depends on portion, processing and the whole meal.
- Confusing a nutrition content claim (e.g. "low fat") with a health claim (e.g. "calcium for strong bones"), which has stricter conditions.
- Answering "what is a healthy diet" with a list of foods rather than a framework of proportions, variety and limiting discretionary foods.
- Ignoring that correlation between diet and disease is not proof of causation.
- Forgetting that the nutrition information panel is per 100 g and per serve - compare like with like.
Worked example
A cereal box claims "high in fibre". A strong answer checks the nutrition information panel: fibre per 100 g and per serve, the ingredient list order (is whole grain first?), added sugar and sodium, and the serving size. It then judges whether the claim is meaningful for a realistic portion, and notes that "high in fibre" is a nutrition content claim with a defined threshold, not proof the product is a healthy choice overall.
Rule of thumb
Evaluate any food product in three steps: read the claim, check the panel per 100 g and per serve, then compare against the Dietary Guidelines and the whole diet.