Measuring practical knowledge about balanced meals: development and validation of the brief PKB-7 scale.
OBJECTIVE
As a high-quality diet is associated with a lower risk for several diseases and all-cause mortality, current nutrition education tools provide people with information regarding how to build a healthy and a balanced meal. To assess this basic nutrition knowledge, the research aim was to develop and validate a brief scale to measure the Practical Knowledge about Balanced meals (PKB-7).


METHODS
A pool of 25 items was pretested with experts and laypeople before being tested on a random sample in Switzerland (n=517). For item selection, a Rasch model analysis was applied. The validity and reliability of the new scale were assessed by three additional studies including laypeople (n=597; n=145) and nutrition experts (n=59).


RESULTS
The final scale consists of seven multiple-choice items, which met the assumptions of the Rasch model. The validity of the new scale was shown by several aspects: the Rasch model was replicated in a second study, and nutrition experts achieved significantly higher scores than laypeople (t(148)=20.27, P<0.001, d=1.78). In addition, the PKB-7 scale was correlated with other nutrition-related constructs and associated with reported vegetable consumption. Test-retest reliability (r=0.68, P<0.001) was acceptable.


CONCLUSIONS
The PKB-7 scale is a reliable and a valid Rasch-based instrument in Swiss citizens aged between 18 and 80 years for measuring the practical knowledge about balanced meals based on current dietary guidelines. This brief and easy-to-use scale is intended for application in both research and practice.
Consumer Behavior, Institute of Environmental Decisions (IED), Zurich, Switzerland.
S
S
Mötteli
Consumer Behavior, Institute of Environmental Decisions (IED), Zurich, Switzerland.
J
J
Barbey
Consumer Behavior, Institute of Environmental Decisions (IED), Zurich, Switzerland.
C
C
Keller
School of Health Sciences, Faculty of Health and Medicine, The University of Newcastle, Callaghan, New South Wales, Australia.
T
T
Bucher
Consumer Behavior, Institute of Environmental Decisions (IED), Zurich, Switzerland.
M
M
Siegrist
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D000072001:Diet, Healthy; D005260:Female; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D008297:Male; D062407:Meals; D008875:Middle Aged; D064686:Nutritionists; D011795:Surveys and Questionnaires; D013557:Switzerland; D055815:Young Adult