School meals in Britain were originally introduced in the early 1900s to combat malnourishment of the destitute. Formal nutritional standards were introduced in 1941, abolished in the 1980s to cut public expenditure and later reintroduced in the early 2000s with the latest update occurring in 2014 (1) . Presently little is known about how the nutritional contents of school meals have changed since being introduced. The present study aims to explore how the nutritional composition of school meals has evolved over time. Historical records of school meal menu plans and recipes were sourced from catering companies and museums for the 1940s-1970s and 2000s-2020s. No records were sourced for the 1980s and 1990s thus these decades were omitted from this analysis. Three average weeks of menus (n= 15 meals) were chosen per decade to provide a snapshot of typical meals served at that time. Corresponding editions of McCance and Widdowson’s ‘The Composition of Foods’ were utilised to calculate the nutritional composition of composite meals for each decade (2) . One-way ANOVA analyses with a Tukey correction to p-values were performed to examine differences in mean nutrients (per 100g) between decades using R (3) . For all tests, significance was determined at P< 0.05. Portion sizes have reduced significantly from the 1940s (mean=588.91g (SEM= 28.01)) to present day (337.4g(23.45)) alongside reduced kilocalories (1940s: 997.71kcal(30.30); 2020s: 540.94kcal (31.08)). Despite substantial changes in the foods typically provided, mean nutrient content has remained relatively stable over time for most nutrients. Folate contents per 100g increased three-fold over the period from the 1960s (5.04µg(1.11), 1970s: 12.58µg(1.48), 2000s: 15.44µg(1.41), 2010s: 11.96µg(0.80), 2020s: 17.46µg(1.10)). Thiamin contents increased in the 2020s (0.16mg(0.03)) in comparison to the previous 4 decades (1960s: 0.08mg(0.004), 1970s: 0.08mg(0.005), 2000s: 0.10mg(0.01), 2010s: 0.10mg(0.01)). Zinc content fell sharply between the 1970s (1mg(0.09)) and proceeding decades (2000s: 0.55mg(0.05), 2010s: 0.58mg(0.07), 2020s: 0.57mg(0.05)). Although not significant, sodium contents of meals per 100g showed a general decline over time (1940s: 268.93mg(29.8), 1960s: 242.63mg(29.88), 2000s: 218.62mg(39.43), 2020s: 119.44mg(14.09)). Contents of key nutrients including vitamins B12, D, and C, calcium, magnesium and iodine remained relatively stable over the decades. Changes in nutrient composition of school meals were driven mainly by reducing portion size between the 1940s and 1970s. Energy density and nutritional composition per 100g have been relatively stable over the period, although folate and thiamin have increased and zinc decreased. These reductions correspond with the reduction in poverty post-war, increasing sedentary lifestyles and concerns over rising prevalence of childhood obesity. Due to lack of records during the 1980s and 1990s, analysis on the nutritional contents of school meals when nutritional standards were removed was not possible. The changes in folate and zinc warrant further future investigation but could potentially be due to inclusion of differing foods over time.
O’Dell et al. (Fri,) studied this question.