Position Statement of the Polish Academy of Sciences’ Committee of Human Nutrition Science on the Principles for the Nutrition of Preschool Children (4–6 Years of Age) and Early School-Age Children (7–9 Years of Age)

It is difficult to rigorously specify the limits of the development of preschool (4–6 years of age) and early school-age (7–9 years of age) children. Similar to earlier developmental periods, in this period, there is a great inter-individual variation, while the differences in body weight and height, their proportions, and the maturity of individual organs and systems are more pronounced than in post-infancy. This is probably related to the production of human growth hormones (HGH – somatotropin) by children. The hormone secretion increases in the first 4 years of life and amounts to approximately 90 μg per day in children before sexual maturity. HGH secretion by the cells of the anterior lobe of the pituitary gland is strongly stimulated by ghrelin, which acts synergistically with GHRH (somatoliberin) and the release of which may be inhibited by excessive activity and exhaustion of the child [140, 141]. The maximum release of HGH takes place at night, 1 to 4 hours after falling asleep [94, 2]. HGH acts among others by stimulating the secretion of the so-called insulin-like growth factors I and II (IGF-I and IGF-II) by the liver but also by other tissues. HGH, along with IGF-I, stimulates protein synthesis in the body, but also participates in the metabolism of carbohydrates, lipids and minerals [19, 77]. Under its influence, during the growth of the body, the metaphyseal cartilages of long bones widen, and the bones grow in length [78]. Therefore, the time and duration of sleep of children, as well as the children’s diet, in particular the type and amount of protein in the diet, are also important during the developmental period [51]. Between 5 and 6 years of age, fast increase in muscle mass is observed, which results in/enables high mobility of children, and thus special attention must be paid to the energy value of the diet. However, compared to high dynamics of the processes taking part in the bodies of infants and post-infantile children, physical development of children aged 4–6 years and 7–9 years is slower and changes take place gradually. Annual increases in body height amount on average to 6–8 cm and 4.5–5.5 cm, respectively, for preschool and early school-age children, and in body weight to 2–3 kg. Boys grow more intensively between 3 and 6 years of age, and girls between 3 and 4 years of age [27].

During the discussed developmental periods, a particularly intense development of cognitive functions, including speech, memory, thinking and attention, takes place [136]. It is related to further development of the nervous system, including the formation of new neurons, axon myelination, glial cell proliferation and neurotransmitter biosynthesis. This requires special attention to ensure an adequate dietary intake of protein with high nutritional value (containing, among others, amino acids such as tryptophan, phenylalanine, tyrosine), polyunsaturated fatty acids from the n-3 family (including docosahexaenoic acid, DHA and eicosapentaenoic acid, EPA), specific minerals (such as iron, iodine, zinc), vitamins from B group (B1, B6, PP, B12, folic acid) and vitamin D.

During the preschool period, children’s appetites may change day by day, which parents/caregivers should have in mind in particular when feeding. During preschool and early school age, changes occur in children’s digestive tracts, which, although it has full digestive efficiency, is very sensitive to various factors, including an improper diet and foods of inappropriate health quality (including microbiological quality). The review of literature demonstrates that in preschool and early school-age children, despite the functional maturation of their kidneys [108], attention still should be paid to dietary sodium intake due to the possibility of hypertension in adulthood [42, 60]. This is also the period when children begin to lose their primary teeth and first permanent teeth appear, which also requires changes to the diet [47].

Numerous irregularities observed in the nutrition of children have plenty of consequences, including with respect to health. The effects of nutritional irregularities in children are not easy to identify since, most often, they are manifested as subclinical symptoms of nutrient deficiencies of a non-specific nature and mild course and as symptoms of inappropriate energy intake (being underweight or overweight). Malnutrition in every form presents significant threats to health, in particular of young children. Currently, we see a double burden of malnutrition that includes both energy and nutrient deficiency and the resulting underweight and stunting in children, as well as deficiency of numerous nutrients, also in some overweight children. Undernutrition, including deficiencies of vitamins and minerals, and deficiencies of bioactive compounds, impairs healthy, regular development and well-being. At the same time, growing rates of overweight and obesity are linked to a rise in non-communicable chronic diseases. According to the WHO, both underweight and overweight are among ten factors which are most harmful to human health [128, 131, 72].

Overweight and obesity are not only aesthetic issues and developmental disorders, but also have long-term health consequences. The metabolic consequences of obesity, resulting from both the amount of adipose tissue in the body and the inflammatory processes occurring therein, include carbohydrate metabolism disorders, which include prediabetes and type 2 diabetes; lipid metabolism disorders; hypertension; non-alcoholic fatty liver disease; hormonal disorders and skin lesions. Obesity is also associated with gastroesophageal reflux, lung ventilation disorders (obstructive sleep apnea, asthma), orthopaedic complications, but also with mental problems, for example, poor well-being, lack of acceptance of one’s own body, lowered self-esteem, social isolation and thus difficult relationships with other people. This may lead to neurotic disorders or depression and eating disorders, which also have serious health consequences.

In view of numerous threats associated with inappropriate lifestyle, including both excessive body weight and underweight, and their impact on health, it is necessary to constantly monitor the physical development of children using anthropometric measurements.

The diagnosis of overweight and obesity in children and adolescents is more complex than in adults. It is necessary to take into account the specifics of the developmental period, the course of growth and maturation depending on gender, as well as the adipose tissue distribution. Individual differences in the structure and composition of children’s bodies are also important. Therefore, regular anthropometric measurements are necessary (at least once a year), and the results obtained should be compared with appropriate reference systems taking into account children’s age and gender, that is, development standards, developmental norms and reference values [101].

The diagnosis of overweight and underweight in children is most often performed using anthropometric measurements, such as height, body weight, waist and hip circumference, and indicators calculated on their basis, including the body mass index (BMI) and the waist-to-height ratio (WHtR). In order to interpret the results for children over 4 years of age, using OLA/OLAF percentile charts is recommended, and in the case of BMI, using BMI percentile charts and z-score developed by the WHO (WHO Child Growth Standards for children 0–5 years), while in children over 5 years of age, using BMI percentile charts for the Polish population (OLA/OLAF) is recommended [101, 58, 102]. It is emphasized that BMI values in children aged 1 and 5 years may be important predictors of body weight in the future [12]. Waist circumference, after reference to appropriate developmental norms (OLA/OLAF percentile charts), facilitates the assessment of the adipose tissue distribution in the body, and the proposed criterion for diagnosing obesity is defined as values above the 95th percentile [11]. WHtR values of ≥ 0,5 may be useful for finding abdominal obesity in individuals starting from 5 years of age [8].

The most common childhood diseases resulting from dietary errors and other lifestyle irregularities, apart from those mentioned above, also include distortions of the development of the skeletal system and teeth.

Oral health is a constituent of overall health and is largely determined by health behaviours of an individual and by environmental factors (sociodemographic, economic, cultural) [96]. Oral health in children means the lack of caries in primary and permanent teeth, the appropriate condition of periodontal tissues and the absence of dental abnormalities and malocclusion [68]. The oral health of children affects their quality of life and may be the reason for problems with chewing, swallowing, breathing, and sleeping, as well as a source of psychosocial problems for children and their families [17].

In Poland, the major health problems in terms of oral health in children during early childhood include high prevalence and intensity of caries in primary teeth, negligence with respect to prevention and treatment, high incidence and severity of complications of untreated dental caries, high prevalence of malocclusions and dental anomalies [84, 83, 87, 86, 54]. Prevalence and intensity of dental caries in children and adolescents in Poland are among the highest in Europe. Carious lesions are reported in over 40% of 3-year-olds, and the incidence of caries increases with age. Dental caries is present in 76.8% 5-year-olds, 81.6% of 6-year-olds, and in children at the age of 7 its incidence stands at 85.1% [90]. In a 5-year-old almost five teeth on average are affected by caries. In Poland, 13.2% of children aged 5 years have never visited a dentist. The conservative dentistry treatment ratio among 5-year-old children is at a very low level and amounts to 0.15

The conservative dentistry treatment ratio is the quotient of the number of teeth with fillings and the sum of the number of teeth with active caries and fillings.

The formation of proper hygiene and nutritional habits and health-promoting attitudes in children, and, consequently, subsequent oral health of the children are influenced primarily by parents’ health awareness of the principles of proper oral hygiene and the importance of undisturbed physiological activities such as breathing, swallowing, chewing and speaking, as well as their activity in eliminating harmful eating habits and using fluoride prevention [113, 49]. According to the recommendations of a team of experts in the field of paediatric dentistry and paediatrics, established as part of the activities of the Working Group on Fluoride Prevention of the Polish Branch of the Alliance for a Cavity-Free Future (ACFF), in children under 6 years of age the only form of home prevention is brushing the teeth twice a day using a fluoride toothpaste (concentration 1000 ppm F): in the morning after breakfast and in the evening after a meal. Children up to the age of 8 years should have their teeth brushed by their parents/caregivers, and in the following year, this procedure should be supervised. Fluoride prophylaxis, apart from a proper diet, remains the basic method of preventing dental caries [53, 89, 85, 88].

Proper nutrition is one of the most important elements of a healthy lifestyle that affects human health and well-being from the moment of conception, through childhood, adulthood, and old age. Food should be safe, not only in terms of broadly understood health quality, including microbiological and technological purity but mainly in terms of nutritional value. Appropriate quality of food determines good health and the achievement of potentially the highest quality of life in physical, emotional and intellectual terms [37, 51, 131].

Proper feeding fulfils all nutritional needs of children in terms of energy and nutrients, except for vitamin D, which in our latitude should be administered as a dietary supplement/drug in accordance with medical recommendations [97, 120]. Monitoring the diet with respect to the nutritional status, which is the result of nutrient intake, digestion, absorption and assimilation, allows for early intervention if potential disturbances in the growth and maturation processes are found [138, 40, 9, 34, 1, 6, 10, 71, 22, 104].

The nutrition of children should comply with the model of safe nutrition in which special attention is paid to the organisation/frequency of meals served to children within a day, selection of products in the diet and the nutrient profile, as well as other factors, including those promoting healthy behaviours and eating habits [82, 126, 127].

The most important components of the safe nutrition model are presented below: (1)

The recommended number of meals to be consumed by preschool and early school-age children in a day should be four to five. The meals can be prepared and served at home and/or in care and educational facilities offering mass catering (e.g. kindergartens, children’s homes, schools). The solutions concerning the organisation of the feeding of preschool and school children depend on the form of care. Over 90% of children aged 3–6 years in Poland attend kindergartens [93].

Depending on the time spent by children in kindergartens, they have from one to three meals outside the home. Those meals usually include breakfast and/or lunch, and afternoon snack, while at home children usually eat dinner or lunch and dinner in one. Early school-age children usually have meals at home (breakfast, lunch, dinner). However, approximately 17–19% of children aged 8 years do not eat breakfast at all [35, 36], and a significant percentage of children do not bring second breakfast with them and do not eat any meal at school [57, 122, 73].

Table 4 presents the current nutritional standards developed by the team from the National Institute of Public Health – National Institute of Hygiene – National Research Institute (NIZP-PZH-PIB) for the Polish population, including preschool and school-age children [51], in terms of the adequate intake (AI) or Estimated Average Requirement (EAR) and Recommended Dietary Allowances (RDA) [51].

– Proteins are mainly used for building the cell structures in the body. They also act as apoproteins in oxygen carriers (globin), control the growth of cells and their vital functions and receive, transmit and store information in the nervous system. Amino acids, that is, the basic components of proteins, are necessary for the synthesis of many important compounds necessary to maintain the functioning of the body, for example, nucleic acids, enzymes, hormones and some vitamins.

The sources of complete proteins in children’s diets include meat and meat products, milk and dairy products, including fermented milk products, and eggs. Plant protein derived mainly from grain products and pulses should complement the range of amino acids provided with animal protein. Thus, the recommended ratio of animal protein to plant protein is 2:1. Excessive protein intake by children may be related to the risk of overweight and obesity [125].

– The role of fats in the body is not limited only to their energy function (1 g of fat provides 9 kcal), but they also have a structural function. The components of fats, mainly fatty acids, and in particular polyunsaturated fatty acids, are structural elements of cell membranes, including the brain, and precursors of biologically active substances, that is, hormones, enzymes and vitamins [37]. Therefore, the type and quality of consumed fats are very important. In the diets of children, it is important to ensure an appropriate share of vegetable oils, including rapeseed oil, olive oil, fatty saltwater or freshwater fish, as well as milk fat (butter). The insufficient amount of fat in children’s diets increases the risk of stunting and even malnutrition. However, excessive intake of products containing saturated fatty acids and cholesterol (e.g. fatty meat, high-fat dairy products) and foods containing trans isomers of polyunsaturated fatty acids (e.g. confectionery) increase the risk of obesity, cardiovascular diseases and metabolic disorders [30, 31, 65]. However, there are studies which prove that the consumption of milk and dairy products with a higher fat content by children is not associated with excessive weight gain and, consequently, is not associated with overweight and obesity in adulthood [50].

– Carbohydrates mainly provide energy (1 g provides 4 kcal) to the body. In the diets of children, complex carbohydrates (starch) from grain products, vegetables and pulses should prevail. Starch is present in groats, flour and products/dishes prepared from flour and cereals, as well as tuber vegetables (e.g. potatoes, sweet potatoes). A very important role, including the regulation of the digestive tract functioning, is played by dietary fibre, which is present in whole grain products and vegetables, and, in smaller amounts, in fruits [28, 117, 15].

Excessive share of carbohydrates, in particular simple sugars (e.g. glucose, fructose) and disaccharides (e.g. sucrose), in the diet is unfavourable for children’s health, because it may promote increased weight gain, leading to overweight or obesity and other non-communicable chronic diseases (e.g. diabetes, cardiovascular diseases) and dental caries [46, 30, 15]. The recommended share of total carbohydrates in the diet is the result of the percentage of energy that should be provided after subtracting the energy provided by protein (10–20% of total daily energy) and fat (20–35% of total daily energy), that is, it is approximately 45–65% of the total daily energy intake.

In general, the recommendations of various expert bodies on sugar consumption are consistent – the less sugar in children’s diet, the better for their health – but they refer to different definitions of sugars

Sugars – the term is currently applied to mono- and disaccharides present in foods (regardless of their origin, i.e. natural or added). Sugars do not include polyols (alcohols - derivatives of monosaccharides, e.g. sorbitol, xylitol, mannitol), although according to European food law they are classified as carbohydrates [37].

– The role of vitamins and minerals in the body is related to its proper functioning in terms of structural, metabolic and regulatory processes, including those related to immunity [37, 112]. Vitamins and minerals should come from a variety of fresh and minimally processed foods due to their better bioavailability than from highly processed, reheated or long-stored foods, and their dietary sources should not be replaced with dietary supplements since their bioavailability from supplements is unknown [37, 137, 76, 70, 52]. It is believed that the vitamin D intake by the body should be additionally increased through supplementation, since this vitamin has multidirectional effects in the body, and there is high probability of insufficient intake of vitamin D in children’s diets and, consequently, the risk of its deficiencies in the body [98].

Nutrition of children in kindergartens, schools or other care and education facilities is one of the elements supporting the children’s development and health, and may also have an educational function. Nutrition in such facilities should be based on proper nutrition guidelines described and/or presented in an accessible way, for example, as a healthy eating plate; it should fulfil the current nutritional standards and comply with the applicable legal regulations. Children are very sensitive to excess or deficiency of energy and nutrients, and therefore it is recommended that nutrition in kindergartens or other care and education facilities should be planned on the basis of RDA or AI, if there is no RDA for a given nutrient. For the energy value of the diet, this is the level of Estimated Energy Requirement (EER), because it is only at this level that recommendations for energy are specified. The use of a nutritional standard at the RDA level covers the demand for nutrients in almost all individuals/children in the group (97.5%) [51].

A typical preschool diet encompasses one to two main meals and one to two complementary meals, planned to provide approximately 75% of the daily energy intake and an adequate amount of nutrients. Breakfast should provide approximately 25% of the daily energy intake, second breakfast around 10%, lunch around 30% and afternoon snack around 10%, with the nutrient intake adjusted to the energy intake in the meal. A school diet usually includes one meal, that is, lunch, and in the case of children from the youngest grades, also a second breakfast. Lunch should provide 30–35% of the daily energy intake and be properly composed in terms of nutritional value and sensory quality. In mass catering, it is recommended to plan meals in a system for at least 10 days or longer, even monthly. This enables better planning of rational shopping, assessing whether the planned diet is not monotonous in terms of the selection of products, dishes, culinary techniques, and also establishing whether it is appropriately diversified and includes all product groups and appropriate proportions between them [133]. In educational facilities, local, seasonal and sustainably produced foods should be introduced as an element of promoting a diet that respects the environment. This allows us to prevent and reduce the amount of food waste in educational facilities through the use of practical solutions, which is an effective tool for environmental protection. Care should also be taken to ensure unlimited access to drinking water in schools/kindergartens and to promote water consumption, also during meals [Stanowisko Komitetu Nauki o Żywieniu Człowieka Polskiej Akademii Nauk w sprawie posiłków szkolnych i nowych standardów żywienia w szkołach 2019].

The solutions with respect to organising the nutrition of preschool and school-age children depend on the form of care and the time that the children spend in the facility. Meals prepared at home require special attention in the context of nutrition in kindergarten/school, for example, dinner or lunch and dinner in one for preschool children or breakfast, lunch and dinner for school children.

Since 2016, the amended Regulation of the Minister of Health on groups of foodstuffs intended for sale to children and adolescents in education system units and the requirements to be met by foodstuffs used in the collective feeding of children and adolescents in these units [103]. The provisions of the Regulation focus primarily on the proper selection of foods in relation to nutritional recommendations and the correction of the most common irregularities in the nutrition of children and adolescents, including reducing the consumption of foods with added sugars and sweeteners, foods high in fat, salt/sodium; and increasing the intake of vegetables, fruit and fish. According to the provisions of the Regulation, foodstuffs used in the collective feeding of children and adolescents must meet the appropriate requirements for a given age group, resulting from the current nutritional standards for the Polish population. They should be selected in such a way that the daily diet consists of food products from different food groups, which ensures appropriate diversity of the diet. Main meals (breakfast, lunch, dinner) must contain products from the following groups: grain products or potatoes, vegetables or fruits, milk or dairy products, meat, fish, eggs, fats and other products – nuts, pulses and other seeds.

Parents of children attending kindergartens/schools should be encouraged to get interested in the nutrition of their children outside the home. Home-made meals should complement the kindergarten/school diet, both in terms of nutrients and food products. This will allow for the proper balancing of children’s diets, including avoiding deficiency or excess of specific nutrients, which is often observed in both individual/home and collective nutrition [92].

Primary teeth and immature permanent teeth are particularly susceptible to the development of caries, and thus the period of increased susceptibility to caries begins with the occurrence of the first primary teeth and lasts until approximately 15–16 years of age. In the majority of children, permanent teeth begin to replace primary teeth at preschool age. Therefore, it is important to pay attention to adequate intake of nutrients influencing the structure of permanent teeth and to eating behaviours supporting the maintenance of health of primary teeth, since it was demonstrated that the presence of carious lesions in primary teeth is associated with a significant risk of the development of caries in permanent teeth [62].

The foods consumed may be a source of minerals necessary for the proper course of odontogenesis and remineralisation of enamel, and the diet may support self-cleaning of the oral cavity and stimulate the salivary glands to secrete saliva with a high content of compounds capable of buffering acids and maintaining the healthy condition of teeth and periodontal tissues.

Products supporting the maintenance of dental and periodontal health include unsweetened dairy products, especially hard rennet cheeses, which stimulate saliva secretion when chewed, contain also calcium and phosphorus necessary for the remineralisation of enamel, and the lipids present in those products create a protective film on the teeth surface against the activity of acids. It was proven that casein phosphopeptide forms a compound with calcium phosphate, increasing the plaque pH and constituting a reservoir of ions for enamel remineralisation [63]. For maintaining dental health, consumption of products containing arginine and dietary fibre was also found beneficial. Products containing fibre, in particular hard, raw vegetables and fruits, during their biting and chewing, mechanically clean the teeth and interdental spaces and stimulate saliva secretion, and the water they contain reduces the cariogenic effect of sugars present in those products. Dietary fibre has a beneficial impact on the composition of microbiota in oral cavity, thus reducing the formation of compounds leading to demineralisation of enamel [107]. Similarly, it is also beneficial to consume whole grain products, which not only contain dietary fibre, but are also a source of ingredients necessary for odontogenesis. In the diets of children, it is worth adding the products that are sources of proteins rich in arginine, which can beneficially modify the composition of the oral microbiota and is metabolized by some dental plaque bacteria, and the products of this transformation neutralize the acidic pH [33]. Arginine-rich foods include pumpkin seeds, sunflower seeds, sesame, nuts, beans, soybeans, lentils, rennet cheeses, beef and turkey meat.

Important factors influencing the process of self-cleaning of the oral cavity include the texture of the foods (non-sticky, hard, stimulating chewing), appropriate intervals between meals and the proper secretion of saliva, which washes the teeth and interdental spaces, thus cleaning and protecting the teeth. Appropriate salivary secretion depends on proper body hydration; therefore, drinking an appropriate amount of water should be one of the elements of anti-caries prevention. The reasons of unfavourable changes in the amount and composition of saliva may also include protein-energy malnutrition, deficiencies of vitamins A, C, D and of minerals – fluorine, calcium and phosphorus [61].

Cariogenic dietary ingredients include beverages with acidic pH and simple sugars, that is, glucose and fructose, as well as selected double sugars, mainly sucrose, which are transformed in the oral cavity into organic acids lowering the pH of dental plaque and contributing to enamel demineralisation, which begins when the pH of dental plaque falls to around 5.5. Free sugars have the highest cariogenic potential [132, 43]. Products containing both sucrose and starch (e.g. sweet cereals, pastries, cookies, wafers) were found to be more cariogenic than those containing only sucrose. This is due to the time needed to neutralize the acidic environment by saliva, which is much longer after the consumption of starch products with the addition of sucrose compared to the consumption of sucrose alone [100]. For the etiopathogenesis of dental caries, it is also important how often cariogenic products are consumed, what their texture is and when they are consumed. Foods with a sticky consistency and containing sugars remain on the teeth surface and in the interdental spaces for a long time. Therefore, frequent consumption of such products is conducive to constant acidity of dental plaque and to demineralisation of enamel, with limited possibility of remineralisation. It is, therefore, less harmful to eat such products once a day and to eat them during the main meal, when other dietary ingredients reduce their cariogenic impact and enable self-cleaning of the oral cavity. Particularly cariogenic products include sweetened carbonated drinks, fruit juices and drinks, which contain large amounts of free sugars (7–10 g/100 ml) and have a low pH due to the organic acids (mainly citric, malic, carbonic, and orthophosphoric acid) they contain.

For children, the best beverage to quench thirst is water. The amount of juices drank within a day should be limited and not exceed 150–200 ml, but children should be encouraged to eat fruits. Drinking sweet beverages and juices, and eating acidic vegetables and fruits between meals, should also be avoided.

Anti-caries prevention is supported by the recommendations of the World Health Organization to limit the consumption of free sugars to less than 10% of the energy value of the diet, which, with an energy intake of 1,400 kcal, corresponds to about 35 g, that is, about 7 teaspoons of sugar per day [132]. According to the latest recommendations, it is beneficial for overall and oral health to limit the consumption of free sugars to less than 5% of the energy value of the diet [4, 37, 32].

In children at particular risk of caries, it is recommended to partly replace sugar with xylitol, which has a sweet taste like sucrose but has anti-caries activity, since it is not metabolised by cariogenic bacteria and does not contribute to lowering the pH in the oral cavity [64]. Xylitol is added to many foods: chewing gums, syrups, milk, candies, jellies and other sweets. The American Academy of Pediatric Dentistry

AAPD - American Academy of Pediatric Dentistry

Summing up, caries prophylaxis in children should include regular consumption of meals; avoiding snacks (in particular sweet snacks); keeping adequate intervals between meals; eating foods with hard texture, stimulating chewing; avoiding mushy and sticky foods; eliminating carbonated and sweetened drinks from the diet and limiting the consumption of fruit juices in favour of eating fruit, drinking milk and still water; limiting the consumption of cariogenic foods (mainly sweets) in favour of less cariogenic and low-processed foods (vegetables, whole grain products, dairy products, nuts) [4, 88].

Fussy eating is a common phenomenon among preschool and early school-age children. It consists of the tendency to reject a large range of foods, including familiar foods eaten earlier and also eaten regularly by other family members. Unlike in the case of neophobia, which consists of avoiding trying new or unfamiliar foods, children who are fussy eaters may at first have a very varied diet, which becomes limited with time [67, 38].

The risk of fussy eating is influenced by the following factors:

Prenatal factors - sensory experience in utero; maternal nutrition during pregnancy;

Fussy eating is a significant source of concern and anxiety of parents and caregivers, which may lead to tensions and conflicts in the relationship between the parent/caregiver and the child. In such circumstances, parents often apply practices which are not only ineffective in extending the food choices but deepen the problem further. Such practices include forcing the child to eat, rewarding and punishing, and negative emotional consequences on the part of the parent/caregiver when the child refuses to eat [67. Negative practices with respect to shaping dietary behaviours in preschool and early school-age children are presented in Table 5 [38]. Practices which facilitate the formation of proper dietary habits in children who are fussy eaters include:

Exposure to varied foods;

Rejection and elimination of a specific food item from the diet is easier for a child than acceptance of a new product. Aversion can develop after only one experience of a specific food, while acceptance most often requires exposure to a specific product several times [55]. Children’s food preferences change as a result of experience, and therefore it is important to enable them to have a free contact with foods and meals. The research show that such strategy is more efficient than rewarding [7, 124]. Exposure to new foods is cumulative – the more new products and meals there are in the child’s diet, the faster they are accepted [79]. Another technique is to combine the sweet taste pleasant for the child with less accepted tastes. Furthermore, multisensory exposure is important, as it involves various senses: taste, smell, touch and sight in contact with a new food product. Research results suggest that multisensory exposures are effective in increasing the consumption of products not accepted by children [23].

Easy access to food also plays an important role. When food is easily available and ready to eat, children eat it more willingly. Among school children, fruit and vegetable intake is higher when these foods are provided in locations accessible to the child and in accessible sizes (e.g., an apple cut into wedges, a carrot cut into sticks) [95].

Preschool and early school period is the time of intensive exploration of the world by the child, which is a result of numerous interactions with the surrounding environment, including the family, peers and school. Starting from the age of 3–4 years, eating is motivated not only by hunger but is also a response to environmental signals. This shows that various family and social factors affect the eating behaviours of children [95].

The key places where children may safely try varied foods and learn to appropriately compose meals are the family environment and the preschool or school facility [91].

Family meals have a significant impact on the eating habits of children. Children who have meals together with other family members eat more healthy foods and their diets are more valuable. It was found that family meals are positively correlated with a lower risk of obesity, higher frequency of consumption of fruits and vegetables, grain products and calcium-rich foods, as well as such nutrients as protein, calcium, iron, folic acid, dietary fibre and vitamins A, C, E and B6. In addition, family meals reduce the probability of skipping breakfast [24].

Meals should be served at regular times and at the family table. Combining meals with watching TV or using a tablet is an inappropriate practice. Such behaviours promote excessive consumption and effectively separate children from hunger and satiety signals. The research shows increased frequency and amounts of tasty and highly processed foods consumed by children who eat meals while watching TV, using a computer, a smartphone, etc. In comparison with children who do not use screens during meals, children from families where contact with electronic media takes place during mealtime consume fewer fruits, vegetables, and grains and more fast foods, snacks and soft drinks [66].

Parents should also take care about the atmosphere during meals. The situations perceived by children as negative and emotionally difficult reduce their willingness to eat and their food preferences. The meal-related situations perceived as positive lead to increased preferences of the child with respect to the consumed meal.

Food marketing may be an important element influencing food preferences and choices among preschool and early school-age children, in particular if it involves a “brand hero”, that is, a character familiar to and positively associated by the child [56]. It was demonstrated that the advertisements of highly processed foods have a negative impact on food choices of children. At the same time, the promotion of healthy foods in various media, including books, publications, brochures dedicated to children could contribute to nutritional education of both caregivers and preschool and early school-age children [39].