This study aims at comparing two Italian case studies in relation to schoolchildren’s plate waste and its implications, in terms of nutritional loss, economic cost and carbon footprint.

Plate waste was collected through an aggregate selective weighting method for 39 d.

Children from the first to the fifth grade from four primary schools, two in each case study (Parma and Lucca), were involved.

With respect to the served food, in Parma, the plate waste percentage was lower than in Lucca (P < 0·001). Fruit and side dishes were highly wasted, mostly in Lucca (>50 %). The energy loss of the lunch meals accounted for 26 % (Parma) and 36 % (Lucca). Among nutrients, dietary fibre, folate and vitamin C, Ca and K were lost at most (26–45 %). Overall, after adjusting for plate waste data, most of the lunch menus fell below the national recommendations for energy (50 %, Parma; 79 %, Lucca) and nutrients, particularly for fat (85 %, Parma; 89 %, Lucca). Plate waste was responsible for 19 % (Parma) and 28 % (Lucca) of the carbon footprint associated with the food supplied by the catering service, with starchy food being the most important contributor (52 %, Parma; 47 %, Lucca). Overall, the average cost of plate waste was 1·8 €/kg (Parma) and 2·7 €/kg (Lucca), accounting respectively for 4 % and 10 % of the meal full price.

A re-planning of the school meals service organisation and priorities is needed to decrease the inefficiency of the current system and reduce food waste and its negative consequences.

To support school foods programmes by evaluating the relationship between nutritional quality, cost, student consumption and the environmental impacts of menus.

Using linear programming and data from previously served menu items, the relationships between the nutritional quality, cost, student consumption and the environmental impacts of lunch menus were investigated. Optimised lunch menus with the maximum potential student consumption and nutritional quality and lowest costs and environmental impacts were developed and compared with previously served menus (baseline).

Boston Public Schools (BPS), Boston Massachusetts, USA.

Menu items served on the 2018–2019 BPS lunch menu (n 142).

Using single-objective models, trade-offs were observed between most interests, but the use of multi-objective models minimised these trade-offs. Compared with the current weekly menus offered, multi-objective models increased potential caloric intake by up to 27 % and Healthy Eating Index scores by up to 19 % and reduced costs and environmental impacts by up to 13 % and 71 %, respectively. Improvements were made by reducing the frequency of beef and cheese entrées and increasing the frequency of fish and legume entrées on weekly menus.

This work can be extrapolated to monthly menus to provide further direction for school districts, and the methods can be employed with different recipes and constraints. Future research should test the implementation of optimised menus in schools and consider the broader implications of implementation.

Restaurants may be important settings for interventions to reduce children’s energy intake. The objective of this study was to test the impact of a parent-focused social marketing campaign to promote healthy children’s meals on calories ordered and consumed by children at quick-service restaurants (QSR).

Using a repeated cross-sectional study design, two urban communities were randomised to intervention (IN) v. control (C) condition. A community-wide social marketing campaign was implemented in the IN community to empower Black and Latinx mothers who frequent QSR (priority population) to select healthier options for their child.

Data were collected in 2016 at QSR located within the communities pre- and post-IN and analysed in 2017.

Parents (n 1686; n 819 and n 867 for I and C conditions, respectively) were recruited after placing their QSR order; a survey, receipt and their child’s leftovers were collected.

Calories ordered did not differ significantly between the IN and C conditions (changeadj = –146·4 kJ (–35·0 kcal); 95 % CI –428·0 kJ (–102·3 kcal), 134·6 kJ (32·2 kcal)). In a sub-analysis of only the priority audience, children in the IN community ordered significantly fewer calories compared to C children in unadjusted models (changeunadj = –510·4 kJ (–122·0 kcal); 95 % CI –1013·4 kJ (–242·2 kcal), –7·5 kJ (–1·8 kcal)), but the trend did not persist after adjusting for covariates (changeadj = –437·2 kJ (–104·5 kcal); 95 % CI –925·5 kJ (–221·2 kcal), 50·6 kJ (12·1 kcal)). Calories consumed followed similar trends.

The campaign did not significantly reduce children’s QSR calories ordered or consumed. However, a quantitatively important mean reduction in calories was suggested among the priority audience, indicating potential for community-wide promotion of healthful children’s meals.

To examine how milk consumption varies by milk choice and measure the association of milk choice on the nutritional and energetic content of National School Lunch Program (NSLP) lunches.

An observational plate waste study using the Digital Photography of Foods Method.

Data were collected from two suburban South Carolina schools in one district during February and March 2013.

Totally, 968 NSLP lunches selected by 619 kindergarten to fifth grade students.

Most students chose chocolate milk (75 %). A multinomial logit model indicated milk choice varied significantly by sociodemographic characteristics. An ordinary least square regression indicated that consumption rates of low-fat white milk were 8·5 % lower than fat-free chocolate milk (P = 0·039) and milk consumption rates varied statistically by sociodemographic characteristics. Ordinary least square regressions found that the consumption of energies and nutrients from NSLP lunches varied with sociodemographic characteristics and milk choice; students selecting chocolate milk consumed 58 more energies (P < 0·001) and 10 more grams of total sugar (P < 0·001) than students selecting low-fat white milk from their NSLP lunches. Students consumed statistically similar energies and nutrients from the non-milk components of their meals.

Students selecting chocolate milk consumed more energies and nutrients from their NSLP lunches with the increases in consumption attributed to the milk component of the meal. The findings have implications for recent changes to NSLP guidelines that allow schools to offer both low-fat and fat-free flavoured milk, reversing the previous ban on low-fat flavoured milk under the Healthy, Hunger-Free Kids Act.

To determine nutritional adequacy of school lunch and to assess the impact of food waste on nutrient intake of primary schoolchildren.

The weighing method was used for evaluating initial servings and plate waste for lunch. Energy and nutritional contents of meals served, consumed and wasted were estimated using the software Food Processor Plus. The mean nutritional value of food served and consumed was compared with dietary guidelines.

Portuguese public primary schools in the city of Porto.

All 525 fourth-grade children, aged from 9 to 10 years old, attending to twenty-one public primary schools.

Overall, school lunches served did not meet the dietary guidelines for energy and nutrients, as only 12·5 % of the evaluated meals were adequate for energy, 33·5 % for proteins, 11·9 % for carbohydrates and 57·1 % for lipids. The majority of meals served were below the age-specific lower limit, namely for energy (83·7 %) and carbohydrates (86·8 %). The only exception, also unbalanced, was observed for proteins, as 42·4 % of lunches served exceeded the recommended upper limit. Furthermore, lunches served and consumed by children did not meet the dietary guidelines for fibre and for the micronutrients evaluated. Children wasted 26 % of the energy content provided in lunches, corresponding to 91·5 kcal, 25 % of proteins and 29 % of carbohydrates supplied.

The lunches served and consumed by children at school canteens failed to meet nutritional standards. These results are not only a consequence of inadequate food portions served but also a result of the high plate waste values observed.

To (i) evaluate food choices and consumption patterns of elementary- and middle-school students who participate in the National School Lunch Program (NSLP) and (ii) compare students’ average nutrient intake from lunch with NSLP standards.

Plate waste from elementary- and middle-school students’ lunch trays was measured in autumn 2010 using a previously validated digital photography method. Percentage waste was estimated to the nearest 10 % for the entrée, canned fruit, fresh fruit, vegetable, grain and milk. Univariate ANOVA determined differences in percentage waste between schools, grades and genders. Daily nutrient intake was calculated using the district's menu analysis and percentage waste.

Elementary and middle schools in northern Colorado (USA).

Students, grades 1–8.

Plate waste was estimated from 899 lunch trays; 535 elementary- and 364 middle-school students. Only 45 % of elementary- and 34 % middle-school students selected a vegetable. Elementary-school students wasted more than a third of grain, fruit and vegetable menu items. Middle-school students left nearly 50 % of fresh fruit, 37 % of canned fruit and nearly a third of vegetables unconsumed. Less than half of the students met the national meal standards for vitamins A and C, or Fe.

Few students’ lunch consumption met previous or new, strengthened NSLP lunch standards. Due to the relatively low intake of vegetables, intakes of vitamins A and C were of particular concern. Effective behavioural interventions, combined with marketing, communications and behavioural economics, will likely be necessary to encourage increased vegetable intake to meet the new meal standards.

To determine the nutritional adequacy and acceptability to children of vegetarian lunches served on ‘Thursday Veggie Day’ – a public health initiative in Ghent (Belgium) primary schools.

A comparison of food leftovers from main courses on regular days and Thursdays was made using a visual plate waste method. The nutritional value of the vegetarian meat analogue and meat components of main courses served on five ‘Thursday Veggie Days’ and five comparable conventional main courses was evaluated using three criteria (maximum 30 % of energy from fat, maximum of one-third of fat as saturated fat and minimum 1·5 g of dietary fibre per 420 kJ).

Two canteens from primary schools in Ghent, Belgium, participating in the ‘Thursday Veggie Day’ campaign.

Primary-school children aged between 6 and 12 years.

In total, 1242 and 472 main course plate waste observations of conventional and vegetarian menus, respectively, were evaluated. There was no significant difference in plate waste between vegetarian (16·7 %) and conventional (17·3 %) main courses. Overall, the five vegetarian components were found to be nutritionally adequate with a mean score of 2·2 out of 3, compared with 0·4 for the meat component. However, three of the vegetarian components provided >30 % of energy from fat and, in one, the amount of saturated fat exceeded one-third of total fat.

Vegetarian canteen meals offered as part of ‘Thursday Veggie Day’ appear to be nutritionally appropriate and as acceptable as conventional main courses to children in primary schools in Ghent.