Terms of the introduction of certain food products into the diet of children of the first year of life

Términos de introducción de ciertos productos alimenticios en la dieta de los niños del primer año de vida

K.E Moiseeva

Saint-Petersburg State Pediatric Medical University;, Rusia

A.V Alekseeva

Saint-Petersburg State Pediatric Medical University, Rusia

Sh.D Kharbediya

Saint-Petersburg State Pediatric Medical University;, Rusia

V.A Gluschenko

Saint-Petersburg State Pediatric Medical University, Rusia

V.V Sokolova

Saint-Petersburg State Pediatric Medical University, Rusia

V.V Kirilenko

Saint-Petersburg State Pediatric Medical University, Rusia

Esta obra está bajo una Licencia Creative Commons Atribución-SinDerivar 4.0 Internacional.

Children’s age is distinguished, first of all, by the processes of intensive growth and development^1,2. Rational nutrition of the child plays a key role in this and contributes to the formation of resistance of the child’s body to the effects of infections and other adverse environmental factors³. There is no doubt that the optimal nutrition for infants is the mother’s milk⁴. It is a source of all easily digestible nutrients and biologically active compounds necessary for a child^5,6,27. In recent years, there was a positive trend in increasing the proportion of children who are naturally fed from 3 to 6 months^7,8,9, which is most likely due to the introduction of the “National program for optimizing the feeding of children of the first year of life in the Russian Federation” in the territory of the Russian Federation in 2009. But at the same time, the proportion of children who are breastfed at the age of 6-12 months, after the jump in 2011, did not show significant dynamics, which is clearly shown in figure 1.

Figure 1
Dynamics of the specific weight of children who are breastfed from 3 to 6 months and 6 to 12 months in 2010-2018 in the Russian Federation (expressed in %)

The World Health Organization (WHO) recommends continued exclusive breastfeeding for children up to 6 months, and to start later with complementary feeding.¹⁰. In the second semester of the firs year of life, the child begins to move actively, so his body requires additional energy and nutrients¹¹. Accordingly, the introduction of complementary foods becomes necessary for normal psychomotor and physical development.

The recommendation to maintain exclusive breastfeed-ing for the first six months of age is supported because it promotes optimal growth and prevents comorbidities, influences cognitive development, and recent findings showthat it participates in the early prevention of chronic diseases. However, considering renal, immunological, gastrointestinal, and neurological development, it is recommend initiating the intro-duction of complementary food between weeks 17 and 26.

Complementary foods are the introduction to the diet of any food different from breast milk or artificial mixture that ensures the growth and proper development of the child. The timing of the introduction of complementary foods is set individually for each child, taking into account the peculiarities of the development of the digestive system, the excretory organs, the level of metabolism, as well as the degree of development and functioning of the central nervous system, that is, his readiness to perceive new food^12,13. According to modern ideas, the introduction of the first products can be started as early as 4 months and as the first complementary foods, as a rule, fruit or vegetable puree is used. Then the second complementary foods are introduced - cereal (porridge). As a third complementary food, according to experts in the field of baby food, it is advisable to use meat puree^14,15. In this case, feeding exclusively with breast milk should be left in the first and last feeding^{16, 17,18}.

When assigning complementary foods they should adhere to the following rules:

· The introduction of each new product begins with a small amount, gradually (5-7 days) increasing to the required volume; at the same time, they monitor carefully the tolerability of the introduced product.

· The new product (dish) should be given in the first half of the day, to mark the possible reaction to its introduction.

· Vegetable complementary foods begin with one type of vegetables, then they gradually introduce other products of this group. The introduction of fruit purees and cereals also begins with monocomponent products.

· Complementary foods are given with a spoon, before breastfeeding or infant formula.

· New products are not introduced if the child is sick, as well as during the period of preventive vaccinations¹⁹.

The timing of the introduction of complementary foods has a significant impact on the child’s body²⁰. The introduction of complementary foods earlier than 4 months of life contributes to the development of functional disorders of the digestive tract in a child (constipation, vomiting, regurgitation, intestinal colic, etc.). Also, the child’s body, not adapted to the use of other food, can respond with the development of food sensitization. However, late complementary foods can also cause a negative reaction of the body, which can lead to pathological conditions, the occurrence of which is associated with a deficiency of nutrients, vitamins, and trace elements; contribute to the violation of the consumption of semi-liquid and thicker food^21,22. Accordingly, the study of the timing of the introduction of certain foods in the diet of children in the first year of life is an urgent topic for research. Thus we conducted the assessment of the timing of the introduction of certain foods in the diet of children in the first year of life.

The study was conducted based on 5 children’s polyclinics (departments) of St. Petersburg by random sampling. According to a specially developed form “Questionnaire of the mother of a one-year-old child”, an anonymous survey was conducted of 534 mothers whose children received breast milk up to a year and older. The majority of mothers were 20-34 years old (84.6%). 15-19 year old women were 8.7%, 20-24 year old -20.6%, 25-29 year old -36.4%, 30-34 year old -27.6%, 35-39 year old -5.8% and 40 year old and older-0.9%. The average age of the respondents was 26.3±0.09 years. The mother independently filled out the questionnaire after children visited local pediatricians or specialist doctors during the medical examination provided by the Order of Ministry of Healthcare after the child reaches 1 year²³. Mathematical data processing was carried out using Microsoft Excel and the statistical software package PASW STATISTICS.

In the guidelines of the World Health Organization “Feeding and nutrition of infants and young children” for the European region, it is noted that a child with breast milk receives the amount of fluid that he needs. Accordingly, there is no need to introduce additional fluids, as they replace more saturated and rich in various nutrients breast milk, thereby preventing breastfeeding. Giving liquids can lead to the child’s dyspeptic disorders. Experts in the field of baby food do not recommend giving the child water and other liquids, except breast milk, up to six months²⁴. However, many pediatricians believe that it is possible to give child water from three months of life. The survey showed that 76.4% of mothers started to give to the infant drinking water earlier than 3 months, and 23.6% at the optimal time. Terms of separate liquids and products in a diet of the child are presented in the introduction of Table 1.

Table 1
Terms of introduction of separate liquids and products in a diet of the child (expressed in % to total)

Half of the mothers started giving the baby juice at 4-6 months, as recommended by pediatricians and nutritionists (50.8%). About a third of women (36.1%) began to give the child juice later than the recommended time, and earlier 13.1% of respondents.

The majority of mothers began to give the child tea (herbal decoctions) in the prescribed period of 4-6 months (42.1%), 21.9% of women participating in the survey gave the child tea earlier, and later 36.0%.

Thus, it was found that on average, respondents began to give child water in 2.27±0.11 months, juice in 6.52±0.10 months and tea (herbal decoctions) in 6.40±0.10 months. A comparative analysis of the actual and recommended average timing of the introduction of certain liquids and products in the diet of the child is presented in figure 2.

Figure 2
The actual average and recommended timing of the introduction of separate liquids and products in the diet of the child (in months)

According to the general recommendations, it is advisable to start the first complementary foods with fruit puree not earlier than 4 months of the child’s life. Then vegetable and grain products are introduced into the diet. However, several deviations in the timing of the introduction of complementary foods, in the form of a later introduction of puree, taking into account the changed ideas about optimal nutrition, has a positive character. Several experts in the field of baby food believe that it is advisable to give vegetables at the beginning and only then fruits²⁵. Most mothers who participated in the study began to give fruit puree at 4-6 months (79.8%). Before the recommended terms, 1.5% of women introduced puree and later 18.7%. The average time of the introduction of fruit complementary foods was 5.74±0.12 months.

Vegetable puree is the primary source of vegetable protein, carbohydrates, vitamins, trace elements, and dietary fiber. As can be seen from Table 1, the majority of mothers began to introduce vegetables at the recommended time (81.1%). 2.1% of women fed the child vegetable puree earlier, and later 19.6%. On average, mothers gave the child a vegetable puree at 5.68±0.10 months.

Grain product (cereals) is of great importance among the various types of complementary foods. Cereals are high nutritional value and a source of almost all elementary substances, such as proteins, fats, carbohydrates and all kinds of vitamins. Grain product is the second complementary foods, which is introduced about a month after the first. Following the recommendations of pediatricians and nutritionists, 71.5% of respondents gave second complementary food to their child in the optimal time, but 4.0% of women began to introduce it before 4-6 months, and 24.5% after 7 months. Average terms of the beginning of the use of grain porridge by the child made 6.15±0.09 months.

Meat puree and cottage cheese paste (cottage cheese) are not introduced into the diet earlier than 5.5 months. Meat complementary foods are the main source of protein of animal origin and many other trace elements. The most optimal timing of feeding meat puree is considered 7 months, in which 13.7% of mothers began its introduction. Earlier this term, it was given by 24.9% of women, and later 61.4%. Cottage cheese and egg yolk is also advisable to introduce no earlier than 7 months. These products are an essential resource of milk protein and fat, as well as more than 20 trace elements and vitamins A, B and D. Cottage cheese paste (cottage cheese) in the optimal time was introduced by 11.5% of mothers, earlier 20.7% of women, and later 67.8%. 10.6% of mothers gave their children egg yolk in 7 months, earlier 30.0%, and later 59.4%. On average, mothers began to give the child meat puree in 7.88±0.10 months, cottage cheese paste (cottage cheese) - in 8.50±0.07 months, egg yolk-8.59±0.08 months.

The subject of discussion of experts in the field of baby food is the late assignment of meat puree (often from 8-9 months), as well as a later introduction to the diet of cottage cheese and egg yolk. The introduction by mothers who participated in the study, of meat puree, cottage cheese and yolk later than the terms, according to some authors of the study, can be considered appropriate and justified²⁶.

Fermented milk products – this is an important part of the diet, but these complementary foods are not recommended to be introduced earlier than eight months of age, as these products can adversely affect the child’s body. 35.5% of women started to give fermented milk products on time, 17.7% of mothers introduced them earlier, and 46.8% later. The average time of introduction of kefir and fermented milk products was 10.10±0.12 months.

Fish is a source of protein and various amino acids, B vitamins, phosphorus, and calcium. Fish begin to introduce into the diet of children from the age of eight months with caution, taking into account that an allergic reaction can develop. The fish puree was given to children from eight months by 17.9% of mothers, before this period 11.0% of women, and later 71.1%. Mothers began to introduce fish into the diet at an average of 10.75±0.11 months.

Whole milk according to modern recommendations in its natural form should not be present in the diet of children under one year. However, only 38.6% of the respondents followed the prescription. The average timing of the beginning of the use of whole milk by a child was 13.32±0.09 months.

It was found that there is no statistically significant difference between the actual and recommended timing of the introduction of water, juice, tea, fruit puree, vegetable puree, and cereal porridge, that is, the timing corresponds to the optimal. The presence of a statistically significant difference between the actual and recommended timing of the introduction of meat puree, cottage cheese paste, egg yolk, dairy products, fish puree, and whole milk confirmed the introduction into the diet of these products later than the optimal timing.

1. Mothers in most cases begin to give the child water in the first year of life in due time. However, a significant number of mothers introduce liquids into the child’s diet earlier than the recommended period.

2. The first complementary foods about 80% of mothers introduced on time. The second complementary foods 71.5% of children were given in due time, and 24.5% - later. The third complementary foods (meat puree), as well as other protein products, which include cottage cheese paste, egg yolk and fish puree, mothers in most cases introduced later than term. Meat puree was introduced earlier by 24.9% of mothers, cottage cheese paste (cottage cheese) – 20.7% of women, egg yolk - 30.0%, and fish puree - 17.9%.

4. Dairy products, including kefir, fermented milk products, and whole milk, most mothers did not introduce in a timely manner. Only 35.5% of mothers started to give fermented milk products on time, and later 46.8%. Whole milk in its natural form was introduced earlier than the term by 61.4% of mothers.

Thus, water, juice, tea, the first and second complementary foods were introduced into the child’s diet in the recommended time, and meat puree, cottage cheese paste, egg yolk, dairy products, fish puree and whole milk later than the established dates, which was confirmed by this study.