Measuring practical knowledge about balanced meals: development and validation of the brief PKB-7 scale

Area of Science:

• Nutrition Science
• Psychometrics
• Health Education

Background:

• A high-quality diet is linked to reduced disease risk and mortality.
• Current nutrition education aims to inform individuals on constructing healthy, balanced meals.
• Assessing practical nutrition knowledge is crucial for effective dietary guidance.

Purpose of the Study:

• To develop and validate a concise scale measuring practical knowledge about balanced meals.
• The scale, named Practical Knowledge about Balanced meals (PKB-7), aims for broad applicability.
• To provide a reliable instrument for assessing basic nutrition understanding.

Main Methods:

• A pool of 25 items was pretested with experts and laypeople.
• Rasch model analysis was used for item selection from a Swiss sample (n=517).
• Scale validity and reliability were confirmed through three additional studies (n=791 total) including nutrition experts.

Main Results:

• The final PKB-7 scale comprises seven multiple-choice items meeting Rasch model assumptions.
• The scale demonstrated validity through replication, higher scores in nutrition experts versus laypeople, and correlations with nutrition-related constructs.
• Acceptable test-retest reliability (r=0.68) was established.

Conclusions:

• The PKB-7 scale is a reliable and valid Rasch-based instrument for assessing practical knowledge of balanced meals in Swiss adults (18-80 years).
• It aligns with current dietary guidelines.
• The scale is brief, user-friendly, and suitable for both research and practical applications.