1. Introduction
Proper nutrition of young children promotes optimal growth and development. The right amount of energy and nutrients also reduces the risk for developing overweight and obesity, dental caries, and gastrointestinal problems like constipation and diarrhea. In addition, there is some evidence that diet quality and especially breakfast consumption is related to cognitive functioning and academic performance of children [
1,
2]. Unfavorable dietary habits may have long-term implications, especially since childhood overweight tends to track into adulthood [
3] and overweight and obesity are major risk factors for cardiovascular disease, type 2 diabetes mellitus, and cancer [
4]. Early childhood is a critical period for prevention of diet-related disease later in life; dietary habits tend to be established at an early age and are maintained throughout later life [
5].
In The Netherlands, about 40% of children until four years of age attend childcare [
6]. Childcare providers are in a unique position to educate parents about healthy eating, to encourage children to eat healthy, and to provide a healthy environment for children to eat, grow and develop. In the current study, food consumption was registered in a large population of young children (10–48 months old) attending day care across The Netherlands. Intakes of energy, macro- and micronutrients and on consumption of a complete set of food groups (e.g., bread, milk products, sweetened beverages) were established and compared with current recommendations. Some of the results have been published previously [
7,
8]; however, these were based on a smaller sample and only comprised a small selection of macronutrients and a few food groups.
4. Discussion
This study showed that Dutch children aged 10 to 48 months, at the days they attended childcare, appeared to have an adequate nutrient intake according to national and European reference values with exception of intakes of total fat, n-3 fatty acids from fish and possibly iron which were all lower than the reference values. Intakes of energy and protein were substantially higher than recommended and part of the population exceeded the Tolerable Upper Intake Levels for sodium, zinc and retinol. Consumption of fruit and fats was substantially less than recommended according to food-based dietary guidelines. So were, to a lesser extent, components of the hot meal (vegetables, potatoes/rice/pasta, and meat/fish/poultry/eggs) and fluids. The children consumed milk products and bread mostly as recommended with respect to type (i.e., low fat and high fiber types, respectively), but milk consumption was on average higher than recommended. A notably high consumption of sugar-containing beverages contributed substantially to energy intake. Almost all children ate breakfast and received vitamin D supplements at the recorded days.
Results presented here are from a large dataset, which covers a very large variety of childcare centers, located across the country. Some limitations should be mentioned. Firstly, the authors were not involved in the design of the data collection methods, nor in the execution of the data collection. It was therefore difficult to evaluate the quality of the data. However, based on the documentation provided and the performed data checks, we assessed the data to be of sufficient quality to merit publication. Missing data on gender, age, and body weight and height reduced the usefulness of the data. However, comparing our results with those of the Dutch National Food Consumption Survey conducted among young children in 2005/2006 in the age categories of 2- and 3-years old overlapping between the studies, we observed that mean energy intake was very similar between the surveys (5632 kJ/day versus 5645 kJ/day, respectively). The Dutch National Food Consumption Survey concluded, based on comparison of energy intake and energy requirement, that underreporting was not an issue in their survey [
24]. We conclude therefore that substantial underreporting is unlikely in our study either. Secondly, there are considerations with respect to the study population and design. During the period of data collection (2011–2014) approximately 40% of Dutch children under the age of 4 attended a childcare center on one or more days per week [
6]. Although formal childcare in the Netherlands is partly subsidized depending on family income, parents (in particular mothers) of children attending a childcare center had on average a higher family income, were more educated and worked more hours per week than parents of other children of the same age [
25]. The study population was therefore not representative of the total Dutch population of 10 to 48 months old. In addition, response rates were not formally monitored. Furthermore, food consumption was only recorded on days that the children attended the childcare center. Although we assumed—to compare the children’s usual nutrient intake distribution with dietary reference values—that the recorded days were representative of a child’s diet, this can be questioned, considering the structure of the day, the food provider, and possible peer pressure. Nevertheless, the data are valuable in their own right. They were mostly observed and recorded directly by the food providers, both at home and at the childcare center. The latter is unusual in food consumption surveys.
As concluded from other studies and countries, reviewed by EFSA [
19], intake of
n-3 fatty acids, in particular DHA and EPA, and iron and vitamin D is low among the Dutch young children. The low dietary intake of vitamin D was largely remedied through the high proportion of children (92%) that received a vitamin D supplement. Although some practitioners doubt whether such a high percentage of supplement users is real, communication about the recommendation has improved since 2012. Intake of
n-3 fatty acids was much lower than recommended. Mean DHA intake by children younger than 2 years is only one fifth of the intake considered as adequate (100 mg/day). Children receiving formula, fortified with DHA, more or less double their DHA intake. If the children of 2 to 4 years old would eat 50 g lean fish and 50 g fatty fish such as salmon per week, as recommended by the NNC, they would easily achieve an adequate intake of DHA and EPA combined. Whether the low
n-3 fatty acid intake has health consequences is uncertain. As for iron, there is evidence that iron deficit at young age may interfere with cognitive development [
26,
27]. However, while the usual iron intake of all children in this survey is above the Average Requirement of 3 mg/day for 1–3 years old established by the US Institute of Medicine [
28], 25% of the children from 1 year do not achieve the Average Requirement of 5 mg/day recently proposed by EFSA [
22]. Recent research in a well-defined, healthy population of 400 young children in The Netherlands has shown that iron deficiency and iron deficiency anemia was detected in 18.8% and 8.5% of the children, respectively, with a lower iron deficiency prevalence among children receiving formula and a higher prevalence among children receiving a large amount (more than 400 mL/day) of cow’s milk after adjustment for age [
29]. However, iron intake was not assessed in this study.
The high intake of energy and protein among young children is also a universal observation across Europe [
19]. They both increase the risk for overweight [
30,
31]. In particular the 1-year-old are at risk: they use a lot of milk, mostly cow’s milk and also formula, and have the highest protein intake. Although no reference value for sugars has been established by the HCN or by EFSA, increasing evidence shows that in particular sugar-sweetened beverages increase the risk of overweight [
32]. We also found that usual intake exceeded the Tolerable Upper Intake Level for zinc (17%) and retinol (30%). As the Adequate Intake and TUIL for zinc are very close, such an excess is inevitable and is unlikely to be harmful. The TUIL for retinol intake among young children is based on the relatively low TUIL for pregnant women owing to its teratogenic effects and adjusted to children. Some excess intake is therefore not likely to be harmful for young children. Also, vitamin A intoxication has not been reported in young children in The Netherlands. Excess retinol intake can nevertheless be avoided if childcare centers and parents restrict the consumption of liverwurst (spread) by their young children, in accordance with the NNC guideline. Dietary sodium intake—70% of the children exceeded the TUIL set by the NNC—is difficult to reduce without endangering a balanced diet. Even though the Dutch bread sector made a major effort to reduce the salt content of bread, bread is a main contributor to young children’s sodium intake. According to EFSA, however, sodium intake is not a matter of concern [
19].
The results of this survey are in particular informative to nutrition policy and education, both for childcare organizations as for parents and youth health care providers. They demonstrate that the young children’s food consumption pattern could be substantially improved by a few changes, such as a replacement of sugared beverages by water and some reduction of milk products. For example, milk-based desserts could be replaced by fruit. Childcare centers that serve a hot meal are able to increase the children’s daily vegetable consumption. All in all, these changes would result in lower energy and protein intake and higher vegetable and fruit consumption, which may in turn lower the risk of overweight. Reduction of a high milk consumption should be able to enhance iron absorption from the diet, as calcium hampers iron absorption. Stimulating fish consumption, both at home and at day care, is a feasible way to increase intake of n-3 fatty acids. Only if, in specific situations, a recommended diet is difficult to achieve, replacement of cow’s milk by formula may help to meet some of the dietary recommendations.
5. Conclusions
Dutch 10 to 48-month-old had, at least on the days they attended childcare, mostly an adequate nutrient intake. The intake of n-3 fatty acids and of iron however was low, which is in line with European findings. This seems a matter of concern in young children in this survey and most likely in all young children in the Netherlands, although more research is needed on their potential health effects. The high intakes of energy and protein in this population are also a matter of concern as they may increase the risk of becoming overweight.
Almost all children ate breakfast and received vitamin D supplements. They used mostly (semi-) skimmed types of milk products and non-refined bread and cereals, as recommended. However, their relatively high milk consumption and very high consumption of sugared beverages are undesirable and the latter should be replaced mostly by water. The relative low consumption of fruit, vegetables and fish, on the other hand, should be increased.