This study aimed to assess the energy and nutrient composition of school meals served in 3 schools in Enugu and Anambra States of Nigeria and their contributions to energy and nutrient intakes of school children. It showed that pulses were consumed on 4 days out of five school days in a week. Cowpeas and bambara groundnuts are among the pulses recognized by Food and Agriculture Organization (FAO)  because of their contributions to protein and micronutrient intakes of individuals. Pulses typically contain about twice the amount of protein found in whole grain cereals and are rich sources of vitamins, iron, zinc, magnesium, bioactive compounds and gives a better protein quality when consumed with cereals [19, 20].
Portion sizes of the school meals consumed by the pupils
In all the 3 schools, the portion sizes consumed by the 2 – 5-year olds were the smallest. This was expected because they cannot consume a quantity that is beyond their gastric capacity. A study showed that the intake of young children remained the same irrespective of the portion size served . This implies that large portion sizes are not necessary for these children rather the emphasis should be on nutrient dense portion sizes.
Energy and nutrient composition of the school meals
The nutrient compositions of the foods per 100 g were in line with the results reported by other researchers [4, 22, 23] on similar foods. These nutrients build and maintain healthy tissues; aid body processes, protect the body against infections and diseases; and provide energy for work . Several dietary components have been identified as having positive effects on cognitive abilities. Dietary factors such as iron, zinc, copper, vitamins B, D, E, C and carotenes can affect multiple brain processes by regulating neurotransmitter pathways, synaptic transmission, membrane fluidity and signal-transduction pathways . This implies that school children can benefit physically and cognitively from school meals. This benefit spans from the nutrients in the meals and its ability to add to total energy and nutrient intakes.
Energy and nutrient intakes of the school children
In all the schools, the intakes increased with age with the 2 – 5-year-olds having the lowest intakes. This is in line with the portion sizes consumed. It was not surprising that the energy and nutrient intakes of the children increased with age since the portion sizes had similar trend. Rolls et al.  showed that larger portion sizes lead to greater energy intake regardless of serving method. The energy expenditure of older children may be higher; therefore a larger portion size prevents negative energy balance and nutrition/health problems associated with it.
That carbohydrate was the main source of energy from the school meals with protein and fat making similar contributions to energy intake was expected. This is necessary to provide readily available energy for school work. Carbohydrates (sugars and starches) provide energy to cells in the body particularly the brain which is a glucose-dependent organ . It also ensures that protein is spared for the function of growth, repair and maintenance of body tissues. The percentage of carbohydrate, fat and protein contributing to energy intake is in line with the dietary guidelines that 45 - 65% of energy be supplied by carbohydrate, 25 – 40% by fat and 10 – 35% by protein . However, the value suggests the need to increase fat intake.
Contribution of the school meals to energy and nutrient intakes of the pupils
School meals should provide at least one third (an equivalent of 33.3%) of the daily recommended nutrient intake (RNI) for energy, protein and other nutrients . The foods consumed by school children in these schools provided more than one third of the RNI for protein, zinc, vitamins A and C but failed to meet a third of the RNI for calcium, iron and energy. These findings are in agreement with the outcome of other researches. Nelson et al.  showed that 4 – 18-year-old pupils in England who received free school meals derived a significantly greater proportion of their daily energy and nutrient intakes from their school meals than those who did not have a free school meal. School canteen lunches provided the most nutritious lunch for Scottish school children, with street lunches providing the least nutritious lunch . A study by Owusu et al.  in Ghana also showed that the meals provided by Non-Governmental School Feeding Programme (NSFP) had larger portion sizes and contributed 28 and 24.6% to energy and protein intakes of the children, respectively. Other researchers [31,32,33] have reported similar findings.
The inadequate contribution made by the foods to energy, calcium and iron requirements of the school children in the 3 schools was in agreement with the report of Nelson et al.  who reported that school meals failed to make good the shortfalls in daily intakes of calcium, iron, zinc, and vitamin A. Our finding was attributed to the portion sizes given the pupils which were not nutrient dense enough to provide the required one third of the energy requirement. Besides, we found that only milk and yogurt provided over 100 mg calcium per 100 g suggesting that a larger quantity and frequency of consumption may increase calcium intake. Use of leafy vegetables alone was insufficient. Factors like cost and availability of funds may have affected the portion sizes due to changes in the school menu with the subsequent effect on the energy and nutrient intakes. Cummings et al.  affirmed that menu changes resulted in a net reduction of calories, sugar and sodium content of meals offered school children. It implies that other nutrients would be affected as well.
Results from studies like this are important for effective policy formulation and implementation especially where nutrition interventions are required. Previous reports [1, 34] have indicated essential roles of school meals in determining adequate health status and general development of school children especially those in areas where school health programme is poorly implemented and school lunch programme not implemented. The limitation of the study is that it focused only on the meals served in PACIEH’s schools since these were the only schools where school meal programme was implemented in the two states. Besides, we did not put into consideration the home meals consumed by the children and the bioavailability of the nutrients especially iron and zinc.
PACIEH should review the school menu to ensure that the quantity of rich sources of calcium and iron are increased. The number of times milk/yogurt and eggs are consumed in a week should be increased. Energy and calcium intake can be increased by use of calcium fortified spreads for bread.