Nutrient density is usually measured per which unit?

• A. per gram
• B. per serving
• C. 100 kilocalories
• D. per day

Answer: (C)

Nutrient density is the amount of nutrients a food provides relative to its energy content, and it is usually expressed per 100 kilocalories. This standardization lets you compare how nutrient-rich different foods are regardless of portion size or total calories. If you expressed nutrient density per gram, foods with higher fat content would appear more nutrient-dense simply because they weigh more, not because they deliver nutrients efficiently per energy. Per serving depends on how large the serving is, which varies widely and makes comparisons inconsistent. Per day blends many foods and makes it hard to judge the density of a single item. Using a fixed energy amount, like 100 kilocalories, provides a consistent basis to see how many nutrients you get for a set amount of energy, which is exactly what nutrient density aims to measure.