Dietary errors in the diet of children attending nurseries of public daycare centers in São Paulo city , Brazil

Instituição: Disciplina de Nutrologia do Departamento de Pediatria da Universidade Federal de São Paulo (Unifesp), São Paulo, SP, Brasil 1Especialista em Saúde, Nutrição e Alimentação Infantil pela Unifesp, São Paulo, SP, Brasil 2Doutoranda do Programa de Pós-Graduação em Pediatria e Ciências Aplicadas à Pediatria da Unifesp, São Paulo, SP, Brasil 3Livre-Docente pela Unifesp; Professor Associado da Disciplina de Nutrologia do Departamento de Pediatria da Unifesp, São Paulo, SP, Brasil RESUMO


Introduction
Nutrition during the first years of life is of fundamental importance for child development, because it is responsible for growth and weight gain, in addition to psychomotor development and prevention of both chronic and acute diseases.To achieve all this, breastfeeding should last for 24 months or more, being exclusive until sixth months, at which point complementary feeding should be introduced, contributing to meeting the child's nutritional requirements in this new phase of development (1)(2)(3)(4) .
Over recent decades, there has been considerable progress worldwide in terms of actions to encourage and promote breastfeeding, but this is not true with relation to complementary feeding, which is habitually begun at the wrong time and is often nutritionally inadequate and unsafe from a microbiological point of view (1,2,5,6) .Information on the least harmful methods of substituting breastmilk when breastfeeding is impossible is also little publicized (7,8) .
Premature introduction of complementary foods during infancy is harmful, both because of the reduction or withdrawal of breastmilk and also because of exposure to factors that can be harmful to the child's health, such as consumption of foods that have been incorrectly handled and the use of utensils such as bottles which increase the chance of contamination and the risk of diarrhea.In contrast, the immunological properties of breastfeeding mean that it acts to prevent gastrointestinal diseases, not only in developing societies but also in the developed world, and offers better weight and height gain in comparison with children who are not exclusively breastfed (1)(2)(3)(4)9) .
Unhealthy dietary practices, especially the premature introduction of unfortified cow's milk, also have a negative impact on iron bioavailability.Establishing good complementary feeding practices, with the introduction of meats and vegetables rich in vitamin C, which increases the availability of iron in other foods, may be important for prevention of iron deficiency anemia -the specific nutritional deficiency that is most prevalent in this age group worldwide (10,11) .
However, the entry of women into the employment market and the resulting demand for institutions that care for and educate their children may cause a significant impact on their diets.Even though Brazilian law protects breastfeeding women who work, with the right to breaks for breastfeeding and daycare provision at the place of work, or nearby, in addition to 6-months' maternity leave, in practice, many women do not receive the benefits set out in these policies (12)(13)(14) .
When mothers are not available to care for their children, they often transfer the care of their infants to institutions known as day-care centers, where the children remain from 8 to 12 hours per day.The menus provided at these institutions are often monotonous, with a predominance of milk-based foods, premature introduction of sugar, tinned foods, processed meat products, desserts and other processed foods.It is necessary that these children be breastfed, both at home and at daycare and that the introduction of new foods be encouraged, preferably natural foods such as cereals, vegetables, meat and pulses (15)(16)(17) .
In view of the important impact on health, growth and development resulting from the acquisition of healthy dietary habits during the first years of life and the harm that unhealthy nutrition can cause, the objective of this study is to describe the dietary errors occurring when introducing complementary foods and providing milk other than breastmilk (hereafter non-breast milk) to children attending public and philanthropic daycare centers in the city of São Paulo.

Methods
This was a descriptive cross-sectional study, which is part of a larger project conducted by the Universidade Federal de São Paulo: the "Effective Daycare Project" studying the impact of training the education professionals at public/philanthropic daycare centers in hygiene and dietary practices and infant health and nutrition.The study was a two-phase randomized institutional trial, with simultaneous control and 7-months' follow-up, conducted between April and November of 2007 with the objective of assessing the effect of training the daycare staff on the infants' health, on knowledge acquisition and on changing practices (11,18,19) .
At the start of the project, 36 daycare centers were contacted, all run by the education department of Santo Amaro, São Paulo.Sixteen of them were visited by the research team, taking into account ease of transport and access.After the initial contact and the information-gathering visits, the selection method proposed by Beghin (20) was used, with the criteria of priority being the largest number of education professionals and infants, safety for conducting the research, no previous health education interventions, the receptivity of the institution and ease of access.On this basis, four public daycare centers and four philanthropic daycare centers were selected.
The study population comprised 255 children of both sexes, aged 5 to 29 months, who were authorized to take part by their parents or guardians, who in turn signed free and informed consent forms.They regularly attended one of the 8 chosen public and philanthropic daycare centers.Children were excluded from the study if they had Down syndrome (n=2), cerebral palsy (n=2) or a genetic syndrome (n=1), if their parents or guardians refused to sign a free and informed consent form (n=2) or if they were absent on the data collection days (n=18), making a total sample loss of 8.9%.
Structured, precoded questionnaires including both open and closed questions were produced and tested in advance of data collection, which was conducted by the project's duly-trained research team between May and November of 2007.
A manual was written for these instruments, containing instructions for the interviewers and the coding for the variables, in order to standardize notation and analysis of the data.All of the questionnaires were analyzed for internal consistency before being input.The data were double-input, with verification for  (21) .The variables analyzed were introduction of non-breastmilk, introduction of complementary foods and the initial consistency of complementary foods, on the basis of the answers to the 24 questions on the questionnaires.For each item, the age of introduction was recorded in months, in observance of recommendations from the Brazilian Ministry of Health and the World Health Organization (WHO) (2,7) .
This project was approved by the Research Ethics Committee at the Universidade Federal de São Paulo, to which it is affiliated.

Results
There was a slight predominance of boys among the children studied (52.9%).Median age was 19 months (range: 5-29).
Table 1 lists accumulated percentages of children by age of introduction of complementary foods.It will be observed that water, juices and non-breastmilk are already being given by 3 months.
Table 2 lists the types of non-breastmilk given to children who were not exclusively breastfed.Note that cow's milk, whether in unaltered liquid form or powdered or diluted, was the most common substitute.Table 3 lists the consistencies of savory meals.Note the predominance of mashing with a fork, followed by liquidizing.

Discussion
Despite all of the benefits and advantages that exclusive breastfeeding offers for a child's health, in our population it is not commonly practiced up to 6 months (1,(22)(23)(24) .Estimated median breastfeeding duration was 341.6 days (11.2 months) in Brazilian state capitals (25) .In this study, introduction of non-breastmilk, which characterizes the start of the predominant breastfeeding period, had occurred in 40% of children by 3 months and in 78.4% by 6 months.Similar findings were reported in a study by Souza et al, which investigated the dietary practices during the first year of life of children cared for at health centers linked to Medical Schools in the city of São Paulo.They observed that 51% were already being given non-breastmilk at 3 months and 75.2% at 6 months (26) .The increased use of non-breastmilk in our study may be the result of the fact that these children attend daycare which very often is not close to where their mothers work, making it impossible for them to breastfeed every time it is required (15,16) .
With relation to the type of non-breastmilk introduced, 68.2% of the babies studied were given cow's milk and 30.6% infant formula.Premature consumption of cow's milk is associated with anemia, due to the low quantity of bioavailable iron and high concentrations of calcium.Studies have also shown that premature introduction can cause micro-hemorrhages in the immature gastrointestinal tract, leading to blood loss (10) .Salvioli et al (27) studied children less than 6 months old between 1983 and 1992 and found a considerable reduction in the prevalence of iron deficiency and of iron deficiency anemia associated with a decrease in feeding with cow's milk, increased use of ironfortified infant formula and greater prevalence and duration of breastfeeding.
The composition of cow's milk is also inappropriate for infants in terms of macronutrients, with high concentrations of protein that can overload immature kidneys and cause allergic reactions, deficiencies of the oligosaccharides that promote protection against infections, and an absence of docosahexanoic (DHA) and arachidonic (ARA) polyunsaturated long chain fatty acids, which are important for children's neurological development.Some infant formulas have DHA and ARA added to their composition, but this may not confer advantages since they may not be as effective as the composition of breastmilk (1) .
The use of infant formula as a substitute for breastfeeding should not be encouraged either, since, in addition to the risks linked to the lack of immunological protection that breastfeeding confers, the mother-child bonding process is compromised and the child's facial muscles do not develop properly because of the lack of stimulation from suckling at the breast.Furthermore, the infant is also exposed to a high risk of contamination from babies' bottles, the use of which demands that the mother or carer is able to ensure hygiene during preparation and to understand the dilution instructions on formula labels (22) .When it is impossible to breastfeed a child, the best alternative appropriate to the situation should be chosen, such as the child's mother's expressed breastmilk or milk from a human milk bank or even a formulated substitute fed by cup (2) .However, what was actually observed in this study was a predominance of unmodified cow's milk being given to substitute or complement breastmilk; either due to a lack of information or to the greatly lower cost when compared with commercial infant formulas.When financial resources are scarce, homemade formulas, such as diluted cow's milk, which was given to just 1.2% of the children in this study, are less harmful than pure cow's milk.In such cases, where unfortified milk is introduced, iron supplementation is necessary to prevent iron deficiency anemia and even children on exclusive breastfeeding should be given iron from 4 to 6 months onwards (7,28,29) .
Complementary feeding was introduced prematurely to the children in this study.At 3 months, approximately 50% of them were being given non-milk liquids and 15% mashes of fruit, vegetables, greens and meat, in line with results from other studies (23,25,(30)(31)(32)(33) .The recommendation, however, is that complementary foods should only be introduced from 6 months onwards, when the child's nutritional requirements exceed that which can be provided by exclusive breastfeeding, thereby guaranteeing sufficient energy, protein and micronutrients.Foods must be safe -prepared and stored hygienically -and should be fed to babies slowly and gradually, without rigidly fixed mealtimes, respecting the child's appetite and satiety, and breastfeeding should be continued (2) .
Liver and fish were the last foods to be introduced: from 7 to 9 months, 55.7% of the children had eaten liver and 33.3% fish.With this diet it is unlikely that a sufficient quantity of iron will be provided, emphasizing the importance of iron-rich foods in complementary feeding.A dietary survey of three daycare centers in Brasília found that a negligible quantity of fish and offal was used in meals.The low availability of these foods at daycare centers may be contributing to the high rates of iron deficiency anemia found in children in this age group (16,17) .
During the first years of life, the diet should be rich in iron including beef, offal, chicken and fish, but even so it may not meet the child's requirements because of the small gastric volume.Pulses can be a good source of iron if eaten together with foods that are rich in vitamin C, which aids in absorption of non-heme iron.In this study, 90.2% of the children aged 7 to 9 months were eating beans.In addition to iron, foods of animal origin are also good sources of protein, zinc, folate and vitamin A (1,2,10) .
With regard to the consistency of foods, 49.4% were liquidized and strained during preparation, which is not indicated because chewing is not stimulated and it makes it difficult to distinguish the textures, flavors and colors of new foods.Introductory complementary foods should be prepared as firm mashes, prepared with a fork, and more solid foods should then be gradually introduced, in order to develop the facial musculature and the ability to chew.From 8 months onwards, children can eat the same food as the rest of the family (1,2,34,35) .
In conclusion, the results of this study have demonstrated that errors in the introduction of complementary feeding to children at these daycare centers were common.These included the age of introduction, consistency and type of foods and particularly the premature use of non-breast milk and other liquids.This practice has a direct impact on the success of breastfeeding campaigns, since this mode of breastfeeding is not ideal and is a long way from what is recommended in order to obtain the protective and potential effects.Furthermore, the fact that these children attend public daycare centers highlights the importance of training the professionals who work there, since they are caring for children who should still be on exclusive breastfeeding and are jointly responsible for the introduction of complementary foods.This study has therefore contributed to illustrating how important it is that these professionals be taught about the importance of correct breastfeeding and complementary feeding for the success of nutrition during the first years of life and, consequently, for good growth and development.

Table 1 -
Distribution of 255 children attending public daycare centers in the city of São Paulo, by age of introduction of water and complementary foods, 2007 error-correction, and analyzed in the statistical program Epi-Info 2000, version 3.4.3

Table 2 -
Types of milk consumed when non-breastmilk is introduced to the diets of children attending public daycare centers in the city of São Paulo, 2007

Table 3 -
Consistency of savory meals given when introduced to children attending public daycare centers in the city of São Paulo, 2007