Diet Quality Index associated with Digital Food Guide: update and validation

Area of Science:

• Nutrition Science
• Public Health
• Dietary Assessment

Background:

• Dietary intake monitoring promotes healthy choices.
• Diet quality indexes aid in assessing nutritional patterns.
• The original Diet Quality Index associated with the Digital Food Guide (DQI-DFG) was adapted for Brazilian dietary habits.

Purpose of the Study:

• To improve and validate a second version of the DQI-DFG.
• To align the index with new evidence on chronic non-communicable disease prevention.
• To ensure the index accurately reflects healthy eating principles.

Main Methods:

• Content validation through expert consensus on healthy eating and the DQI.
• Construct validation involving reference diets, serving sizes, and correlation analyses.
• Reliability testing through inter-rater agreement and score component correlations.

Main Results:

• High correlation (r = 0.78–0.97) between expert scores and DQI-DFG results.
• Balanced influence of index components on the final score (r = 0.49–0.10).
• Expert consensus validated the underlying concepts of the DQI-DFG.

Conclusions:

• The enhanced DQI-DFG is a valid tool for assessing diet quality in Brazil.
• The index demonstrates strong agreement with expert menu evaluations.
• The DQI-DFG effectively supports the promotion of healthy dietary choices.