Food biodiversity: Quantifying the unquantifiable in human diets.

Area of Science:

• Dietary science
• Ecology
• Nutritional science

Background:

• Dietary diversity measurement is crucial for public health, diet quality, and food security assessments.
• Conventional methods fail to capture nutritional variability and ecosystem services within food groups.
• Existing ecological diversity indices need adaptation for dietary assessment.

Approach:

• This narrative review synthesizes conceptual issues in measuring edible species-level food biodiversity.
• It assesses ecological diversity indices applied to food consumption and supply data.
• The review discusses index suitability and proposes amendments for dietary intake studies.

Key Points:

• Dietary species richness, evenness (e.g., Gini-Simpson), and functional dissimilarity indices have limitations when applied to diets.
• Indices often disregard nutritional context, require standardized units, and rely on arbitrary trait selections.
• These limitations can lead to ambiguous or incorrect conclusions about food biodiversity.

Conclusions:

• Future food biodiversity indices should satisfy key axioms and account for inter-species disparity.
• Indices should be used in combination for robust and comparable dietary research.
• Standardized methodologies are needed for accurate assessment of food biodiversity in diets and food systems.