Nutrition Science Fundamentals
Core concepts
A candidate must be fluent in macronutrient energy yields (carbohydrate 4 kcal/g, protein 4 kcal/g, fat 9 kcal/g, alcohol 7 kcal/g), the distinction between essential and conditionally essential nutrients, and the roles of vitamins and minerals as coenzymes and cofactors. Understand protein quality (complete vs. incomplete, limiting amino acids, complementary proteins), glycemic response, fiber types and their physiologic effects, and the basics of fluid and electrolyte balance. Know the difference between fat-soluble (A, D, E, K) and water-soluble vitamins, and which nutrients are most vulnerable to deficiency in restricted diets (B12 in vegan diets, iron and calcium across the lifespan, vitamin D with limited sun exposure).
Traps
Questions often test unit conversions and energy math under time pressure, or blur the line between a nutrient's physiologic role and a food source claim. Watch for distractors that confuse deficiency with toxicity, or that attribute a function to the wrong vitamin. Read whether the stem asks for the most likely or the first step.
Rule of thumb
When computing energy from a label, multiply grams by the correct yield per macronutrient, sum, then compare to total calories to spot rounding or fiber/sugar-alcohol adjustments. Worked example: a food with 30 g carbohydrate, 10 g protein, and 5 g fat yields (30×4)+(10×4)+(5×9)=120+40+45=205 kcal.
Study anchor
Tie each nutrient to one deficiency syndrome and one rich food source; that pairing answers most recall items.