To analyse the Nutritional Knowledge Test (NKT) using Item Response Theory (ITR) analysis and to assess the construct validity of the Nutritional Knowledge Scale (NKTS) and its associations with adolescent food group consumption and nutritional biomarkers.

Cross-sectional study.

Multicentre investigation conducted in ten European cities.

Adolescents aged 12·5–17·5 years (n 3215) who completed over 75 % of the NKT.

Factor analysis indicated that the NKT can be analysed with a one-dimensional model. Eleven out of twenty-three items from the NKT presented adequate parameters and were selected to be included in the NKTS. Nutrition knowledge was positively associated with consumption of fruits, cereals, dairy products, pulses, meat and eggs, and fish, as well as with blood concentrations of vitamin C, β-carotene, n-3 fatty acids, holo-transcobalamin, cobalamin and folate; nutrition knowledge was negatively associated with intake of olives and avocado, alcohol and savoury snacks.

The NKTS assessed nutritional knowledge adequately and it is proposed as a new tool to investigate this subject in future studies.

To build up sufficient knowledge of a ‘healthy diet’. Here, we report on the assessment of nutritional knowledge using a uniform method in a large sample of adolescents across Europe.

A cross-sectional study.

The European multicentre HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) study conducted in 2006–2007 in ten cities in Austria, Belgium, France, Germany, Greece (one inland and one island city), Hungary, Italy, Spain and Sweden.

A total of 3546 adolescents (aged 12·5–17·5 years) completed a validated nutritional knowledge test (NKT). Socio-economic variables and anthropometric data were considered as potential confounders.

NKT scores increased with age and girls had higher scores compared with boys (62 % v. 59 %; P < 0·0001). Scores were approximately 10 % lower in ‘immigrant’ adolescents or in adolescents with ‘immigrant’ mothers. Misconceptions with respect to the sugar content in food or in beverages were found. Overall, there was no correlation between BMI values and NKT scores. After categorization according to BMI, scores increased significantly with BMI group only in boys. These differences disappeared after controlling for socio-economic status (SES). Smoking status and educational level of the mother influenced the NKT scores significantly in boys, as well as the educational levels of both parents in girls.

Nutritional knowledge was modest in our sample. Interventions should be focused on the lower SES segments of the population. They should be initiated at a younger age and should be combined with environmental prevention (e.g. healthy meals in school canteens).

The current paper aims to present the main results of the Italian National Food Consumption Survey INRAN-SCAI 2005–06.

A cross-sectional study was performed. Households were randomly selected after geographical stratification of the national territory. Food consumption was assessed on three consecutive days through individual estimated dietary records.

Italy.

The final study sample comprised 3323 subjects (1501 males and 1822 females) aged 0·1 to 97·7 years belonging to 1329 households: fifty-two infants (0–2·9 years), 193 children (3–9·9 years), 247 teenagers (10–17·9 years), 2313 adults (18–64·9 years) and 518 elderly (65 years and above).

Participation rate was 33 %. The mean ratio of estimated energy intake to estimated BMR was 1·41 in adults. Indicators of mean and high individual consumption are presented for fifteen large categories and fifty-one subcategories of foods and beverages, in the total population and in consumers, by age and sex categories. The overall consumption of fruit and vegetables was 418 g/d. The consumption of red meat was approximately 700 g/week, expressed as raw weight. Some specific aspects of the Italian food consumption pattern were confirmed: a large contribution from bread, pasta and pizza to cereals, from olive oil to fats and from wine to alcoholic beverages.

The database obtained from the survey will be the key reference for Italian food consumption during the coming years and will be utilized for a variety of purposes including the assessment of nutrient intakes and risk analysis.