Foods, Nutrition, and Food Science
This domain tests nutrient functions, dietary guidance, food-label literacy, safe food handling, and the food science behind preparation methods - the content behind nutrition, foods labs, and wellness courses.
Nutrients and energy
- Six classes: carbohydrates, proteins, fats, vitamins, minerals, water. Energy values: carbohydrate 4 kcal/g, protein 4 kcal/g, fat 9 kcal/g, alcohol 7 kcal/g.
- Fat-soluble vitamins are A, D, E, and K; water-soluble vitamins are not stored in large amounts and must be eaten regularly.
- Dietary Guidelines emphases: variety and nutrient density, limits on added sugars (under 10% of calories), saturated fat (under 10%), and sodium (under 2,300 mg/day). MyPlate proportions: half the plate fruits and vegetables, with lean protein and grains.
Labels and planning
- Start with serving size, then read %DV (based on a 2,000-kcal reference diet). Ingredients are listed in descending order by weight; "fat-free" does not mean calorie-free.
- Nutrient density compares nutrients provided to calories supplied; empty calories come from added sugars and solid fats.
Food safety and food science
- Danger zone 40–140°F; the two-hour rule; cook poultry and leftovers to 165°F, ground meat to 160°F; chill promptly and avoid cross-contamination; FIFO rotation; HACCP identifies critical control points.
- Key pathogens: Salmonella, E. coli O157:H7, Listeria, Staphylococcus aureus, and Clostridium botulinum (anaerobic - associated with improperly canned low-acid foods).
- Science: Maillard browning (protein + sugar, dry heat), caramelization (sugar alone), gluten development from wheat protein, emulsions held by emulsifiers, baking soda needing acid while baking powder is self-contained.
Worked example
A snack has 45 g carbohydrate, 20 g protein, and 12 g fat. Carbohydrate 45 × 4 = 180 kcal; protein 20 × 4 = 80 kcal; fat 12 × 9 = 108 kcal; total 368 kcal. Reasoning: apply the correct factor per macronutrient, then sum - never multiply total grams by one factor.
Traps that cost marks
- Confusing serving size with package size when counting calories.
- Using 165°F for every food instead of poultry and reheated leftovers.
- Assuming boiling water sterilizes food or that freezing kills bacteria.