Dietary Behavioural Preferences of Spanish and German Adults and Their Translation to the Dietary Recommendations of a Personalised Nutrition App in the Framework of the Stance4Health Project

Background/Objectives: The influence of individual differences in the selection of food portions can have a deep effect on recommendations for personalised nutrition. In addition to typical aspects such us energy density and nutrient composition, portion size is important for dietary recommendations. This study examined the dietary behaviours and portion size selection of 224 subjects in Spain and Germany to use such information to improve dietary adherence to a personalised nutrition app. Methods: An online questionnaire administered to adults in Spain and Germany collected sociodemographic data and dietary habits. The measurement of portion sizes was derived from a classification ranging from XXS to XL across 22 food groups, with assistance from a photographic atlas. Results: Significant differences across dimensions were found. Dietary habits showed that omnivores were the majority in both countries, with significant differences in the consumption of bread, desserts, and beverages. The Mediterranean diet was significantly followed by the Spanish group, reflecting cultural differences. Body mass index (BMI) was slightly higher among Germans, although both populations fell within the normal ranges. Portion size comparisons revealed statistically significant differences in the consumption of various food items between the two countries. Spaniards consumed higher amounts of rice, meat, and legumes, while Germans consumed larger portions of stews, lasagne, and pizza. These variations highlight differing dietary habits influenced by cultural preferences and dietary guidelines. Conclusions: The findings support the development of novel personalised nutrition apps that consider user preferences and enhance dietary adherence, thereby contributing to improved dietary recommendations and health outcomes.