Iron and zinc are essential dietary minerals fundamental for growth and development in adolescents (Reference Gibson, Heath and Ferguson1,Reference Cleghorn2) . Females at this life stage have increased physiological requirements due to the onset of puberty (Reference Gibson, Heath and Ferguson1). Insufficiency of either mineral can have adverse effect on health including impaired immune competence (Reference Calder3) and cognitive function (Reference Gibson, Heath and Ferguson1). Increased autonomy of food choice may influence diet composition and mineral intake. Furthermore, socioeconomic status has been shown to be positively associated with micronutrient intake (Reference Novaković, Cavelaars and Geelen4).
In this study, secondary analysis of years 7 & 8 of the National Diet and Nutrition Survey (NDNS) was conducted to establish influence of income on mineral intake. Furthermore, micronutrient intakes of females aged 11–14 years were compared to Reference Nutrient Values (RNI) and adherence assessed. We then tested the hypothesis, meals made with ingredients derived from “economy” ranges contain lower levels of iron and zinc. The meal tested was Spaghetti Bolognese made with ingredients from economy and standard ranges from four large UK supermarkets.
Mineral content of homogenised and oven dried Bolognese meat sauce was determined via inductively coupled plasma- mass spectrometry (ICP-MS). The influence of cost on mineral concentration was evaluated using parametric tests.
Correlation analysis performed to test the potential influence of equivalised household income on mineral intake. Non- Parametric tests utilised to compare mineral intake across income quintiles. All data analysed in IBM SPSS v26.
Results from NDNS revealed 98 and 89% of females (n 130) daily dietary iron and zinc intakes were below the Reference Nutrient Intake (RNI) respectively, of this 85 and 68% were below the Estimated Average Requirement (EAR) respectively. Mineral intake increased with increasing income for iron (p 0.014) and zinc (p 0.028). When analysed by income quintiles (IQ) females in IQ 5 (n 22, >£43402.43) had a higher intake of iron (p 0.014) and zinc (p 0.004) compared to females in IQ 1 (n 23, <£12152.43). Bolognese made with Economy (n 12) had the least iron (0.90 ± 0.04 mg 100g-1) and Standard (n 12,) the highest (1.07 ± 0.08 mg 100g-1) although this did not reach significance (p 0.060). Standard Bolognese had the highest concentration of zinc (1.65 ± 0.10 100g-1) and Economy the least (1.44 ± 0.05 mg 100g-1) however, this did not reach significance (p 0.091).
Females aged 11–14 years; intakes of each mineral were low compared to the RNI with those in lowest quintile having a lower intake compared to Quintile 5. More studies are required to investigate the foods and food groups within the diet of adolescent females and potential influence food cost has on mineral intake.
Acknowledgements
This work was supported by the Biotechnology and Biological Sciences Research Council [grant numbers BB/M008770/1]