Relationships Between Taste and Food Intake in Adolescents

Background and aim: Studies that link taste to specific foods have been conducted; however, an evaluation of how taste associates with overall diet is missing. The aim of this thesis was to investigate associations between dietary tastes of UK and Saudi adolescents and overall diet quality and Body Mass Index (BMI). Methods: Following a systematic review to report on the impact of taste on adolescents’ food intake, a list of foods was generated from adolescents’ food records from the National Diet and Nutrition Survey (NDNS). A random sample of adults was asked to identify the main taste for each food. From this, six taste clusters emerged (sweet, salty, savoury, sour, bitter and neutral), which were used to characterise the foods consumed by adolescents in the NDNS by taste. Then, taste patterns were generated, and the diet quality was calculated. Exploring Saudi adolescents’ dietary tastes involved adolescents completing a food-taste survey and self-report their food intake using Arabic myfood24 tool (Arabic foods and their compositions were created and integrated into the tool, which showed acceptable level of usability among Saudi adolescents). Survey responses identified five taste clusters (sweet, salty, sour, bitter, and neutral), which were used to characterise the adolescents’ foods by taste. Multivariable regression analyses were used in both UK and Saudi studies to explore the associations. Results: The systematic review identified limited number of studies and an unclear effect of taste on adolescents’ food choices and intake. Five taste patterns ‒ salad-bar, hot-food, takeaway-meal, sweet-snack, and beverages ‒ were generated from the dietary tastes of UK adolescents, with 2/3 of adolescents’ diet comprised of sweet- and neutral-tasting foods. The highest impact on energy intake was associated with an increase in the consumption of the takeaway-meal taste pattern by 168 kcal/d (95% CI 139, 197; P < 0.01). However, consumption of the taste pattern was inversely associated with BMI by -0.8 kg/m2 (95% CI -1.4, -0.1; P = 0.02). Sweet-snack taste pattern was significantly associated with negative diet quality, while the hot-food taste pattern was associated with a better diet quality 2.0% (95% CI 1.0, 3.1; P < 0.01). In contrast, salty foods were most prominent and preferred in Saudi adolescents’ diet and contributed the highest impact on energy intake (17 kcal/d; 95% CI 13, 22; P < 0.01). Neutral and bitter foods were linked to positive diet quality scores in Saudi adolescents’ diet. However, no relationship with BMI was identified. Conclusion: For the first time, taste characteristics of adolescents' dietary intake were explored. Sweet foods and salty foods dominated the UK and Saudi adolescents’ diets, respectively. Understanding adolescents’ dietary tastes could help improve their food choices.