Food and Nutrition
Scope
Food and Nutrition tests nutrients, energy calculation, menu planning, food safety, and cooking science. Expect questions that require calculating energy from macronutrients, identifying a nutrient function, or selecting a safe food-handling practice.
Core rules
- Carbohydrate and protein provide about 4 kcal per gram; fat provides about 9 kcal per gram.
- A balanced diet supplies energy and essential nutrients in appropriate proportions; nutrient density matters, not only calorie count.
- The food safety danger zone is roughly 5-60 degrees Celsius; perishable food should be kept out of it.
- Cross-contamination is prevented by separating raw and ready-to-eat food and by washing hands and surfaces.
- Cooking can reduce some hazards, but some toxins and spores are heat-stable, so prevention is essential.
Worked example
A meal contains 50 g carbohydrate, 20 g protein, and 10 g fat. Energy = 50 x 4 + 20 x 4 + 10 x 9 = 200 + 80 + 90 = 370 kcal. Carbohydrate contributes 200 / 370 = 54%, protein 22%, and fat 24%. Reasoning: apply the correct energy factor to each macronutrient, then divide each contribution by total energy.
Traps
Using 4 kcal/g for fat underestimates energy. Ignoring serving size misstates nutrient intake. Assuming boiling destroys every toxin is unsafe. Thawing food at room temperature increases bacterial growth.