Table 2.
Structure, internal consistency, and percentage of correct answers of the nutrition knowledge questionnaire for Japanese school children and their guardians.
| Knowledge section | Number of questionsa | Examples of questions | Internal consistency (Cronbach's alpha)b | Percentage of correct answers, mean (SD) | |
|---|---|---|---|---|---|
| NKQ for lower grader (for pupils in grade 1–3) | Total | 26 | 0.66 | 77.4 (11.9) | |
| Categorization of foods based on nutritional similarity | 6 | Circle the item number of one food which is different from other foods in a group of four foods (answer choices: cabbage, cucumber, Japanese radish, rice) | 79.8 (21.4) | ||
| Knowledge about foods as nutrient sources | 10 | Which food contains more salt? (answer choices: pork, sausage) | 72.2 (20.3) | ||
| Physiological function of nutrients in human body | 3 | Choose two foods which mainly work as energy (heat and power) in the human body (answer choices: rice, lettuce, egg, spaghetti, string beans) | 71.0 (17.0) | ||
| Relationship between nutrients and health outcomes | 1 | Choose all foods which should be consumed more to become healthy (e.g. of answer choices: carrot, french fries, milk, chocolate) | 86.0 (14.6) | ||
| Others 1 (e.g. dietary behavior, food choice) | 6 | It is the best for you to flavor foods as you like (answer choices: correct, wrong). | 85.7 (16.5) | ||
| Others 2 (e.g. background of subjects) | (6) | Are you a boy or a girl? | – | – | |
| NKQ for higher grader (for pupils in grade 4–6) | Total | 27 | 0.76 | 68.5 (15.0) | |
| Knowledge about foods as nutrient sources | 7 | Circle the item numbers of three foods which should be consumed when you need calcium (answer choices: buckwheat noodles, tuna, cheese, potatoes, Shirasuboshi,c soybeans) | 72.1 (13.8) | ||
| Physiological function of nutrients in human body | 10 | The nutrient which mainly constitutes blood and muscles is carbohydrates (answer choices: correct, wrong, not sure). | 59.6 (25.4) | ||
| Relationship between nutrients and health outcomes | 10 | Excess energy intake from meals does not cause health problems in children (answer choices: correct, wrong, not sure). | 66.5 (25.1) | ||
| Others 1 (e.g. dietary behavior, communication with families) | (30) | How many times do you have breakfast per week? | – | – | |
| Others 2 (e.g. background of subjects) | (5) | Are you a boy or a girl? | – | – | |
| NKQ for adults | Total | 84 | 0.59d | 70.1 (11.0) | |
| Knowledge about foods as nutrient sources | 42 | Are foods listed below rich in starch? (cheese, butter, nuts, rice, cornflakes; answer choices: rich, poor, not sure) | 74.1 (13.3) | ||
| Physiological function of nutrients in human body | 15 | Only excess intake of fat and oil causes obesity (answer choices: correct, wrong, not sure). | 70.7 (15.8) | ||
| Awareness of dietary recommendations | 5 | According to the recommendation of the Ministry of Health, Labour and Welfare, how much salt intake (gram per day) is recommended for Japanese adults (more than 18 years old)? (e.g. of answer choices: less than 5 g for men, less than 4.5 g for women) | 43.5 (20.5) | ||
| Relationship between nutrients and health outcomes | 22 | Do you think that risk of a certain cancer can be decreased by actions listed below? (e.g. of actions: consume more dietary fiber; answer choices: decrease, not decrease, not sure) | 61.6 (14.3) | ||
| Others 1 (e.g. dietary behavior, communication with families) | (22) | I am careful not to eat too much (answer choices: always do so, do so, rarely do so, never do so). | – | – | |
| Others 2 (e.g. background of subjects) | (13) | Which school did you graduate at last? Circle an alphabet. | |||
NKQ, nutrition knowledge questionnaire.
The number of questions shown in parenthesis was not included in the total number of questions in each questionnaire, because they were not used to calculate percentage of correct answers.
Internal consistency between the knowledge sections was evaluated by calculating Cronbach's alpha.
Shirasuboshi, boiled and dried young anchovies.
Cronbach's alpha for the guardian's nutrition knowledge questionnaire was 0.69 after excluding the section about awareness of dietary recommendation from the calculation. Therefore, this section was excluded from calculation of the percentage of correct answers used in later analysis.