Abstracts

Introduction

Child malnutrition is expressed in different ways, by means of low height-for-age, low weight-for-height or low weight-for-age¹1. Waterlow JC. Note on the assessment and classification of protein-energy malnutrition in children. Lancet 1973; 2(7820): 87-9.. Even though it is a major challenge for low income countries, recent estimates suggest that malnutrition is decreasing in most countries, being replaced by problems related to excessive weight²2. de Onis M, Blössner M. Prevalence and trends of overweight among preschool children in developing countries. Am J Clin Nutr 2000; 72: 1032-9..

Considering that child nutritional status is closely related to the socioeconomic condition of the child, there are differences in this relationship between countries. While nutritional deficits are more prevalent in developing nations and in the lower social classes of these countries³3. World Health Organization, Department of Nutrition for Health and Development. WHO global database on child growth and malnutrition. Disponível em: http://www.who.int/nutgrowthdb/database/en/ (Acessado em 5 de agosto de 2011).
Disponível em: http://www.who.int/nutgro... , the relationship between socioeconomic level and excessive weight is more complex. Even though the prevalence of excessive weight among children is higher in high income countries, in the past two decades the medium and low income countries presented increased proportions of this condition⁴4. de Onis M, Blössner M, Borghi E. Global prevalence and trends of overweight and obesity among preschool children. Am J Clin Nutr 2010; 92: 1257-64.. In the adult population of Brazil, studies point out that there is a direct association between socioeconomic level and obesity among men, while for women obesity is related to poverty⁵5. Monteiro CA, Conde WL, Popkin BM. Income-specific trends in obesity in Brazil: 1975-2003. Am J Public Health 2007; 97(10): 1808-12. ^{, 6}6. Santos, LM. Obesity, poverty, and food insecurity in Brazilian males and females. Cad. Saúde Pública 2013; 29(2): 237-9.. As to children, this relationship is not so clear, but national estimates suggest that the prevalence of excessive weight is discreetly higher in the most favored social classes⁷7. Brasil. Ministério da Saúde. Pesquisa Nacional de Demografia e Saúde da Criança e da Mulher - PNDS 2006. Brasília: Ministério da Saúde; 2008..

Besides nutritional status, other indicators are also related to the socioeconomic level of a family. One of these indicators is food insecurity, since some studies suggest that this condition is associated with low income, low schooling, high home agglomeration, among others⁸8. Panigassi G, Segall-Corrêa AM, Marin-León L, Pérez-Escamilla R, Sampaio MFA, Maranha LK. Insegurança alimentar como indicador de iniqüidade: análise de inquérito populacional. Cad Saúde Pública 2008; 24(10): 2376-84. ^{, 9}9. Bickel GW, Nord M, Price C, Hamilton W, Cook J. Measuring food security in the United States. Guide to measuring household food security. Revised 2000. Alexandria: United States Department of Agriculture; 2000.. Besides, several studies point to the direct relationship between food insecurity and damages on child nutritional status¹⁰10. Rose D, Bordor JN. Household food insecurity and overweight status in young school children: results from the Early Childhood Longitudinal Study. Pediatrics. 2006; 117(2): 464-73.

11. Gundersen C, Garasky S, Lohman BJ. Food insecurity is not associated with childhood obesity as assessed using multiple measures of obesity. J Nutr 2009; 139(6): 1173-8.

12. Hernádez LO, Gutiérrez MNA, Pérez AEN, Fonseca NP, Gómez YR. Em escolares de la Ciudad de México lá inseguridad alimentaria se associó positivamente com el sobrepeso. Rev Invest Clin 2007; 59(1): 32-41.

13. Hackett M, Melgar-Quiñonez H, Álvarez MC. Household food insecurity associated with stunting and underweight among preschool children in Antioquia, Colombia. Rev Panam Salud Publica 2009; 25(6): 506-10. ^{- 14}14. Reis M. Food insecurity and the relationship between household income and children's health and nutrition in Brazil. Health Econ 2011; 21(4): 405-27..

Since food insecurity and problems related to child nutritional status are mostly associated with low income families, several studies have been investigating the association between these two conditions. Some of them observe that, in places with high prevalence of food insecurity, children have more chances of presenting worse nutritional status, developing some sort of deficit¹³13. Hackett M, Melgar-Quiñonez H, Álvarez MC. Household food insecurity associated with stunting and underweight among preschool children in Antioquia, Colombia. Rev Panam Salud Publica 2009; 25(6): 506-10. ^{, 14}14. Reis M. Food insecurity and the relationship between household income and children's health and nutrition in Brazil. Health Econ 2011; 21(4): 405-27.. On the other hand, other investigations suggest that food insecurity can increase the risk of obesity in the child population¹²12. Hernádez LO, Gutiérrez MNA, Pérez AEN, Fonseca NP, Gómez YR. Em escolares de la Ciudad de México lá inseguridad alimentaria se associó positivamente com el sobrepeso. Rev Invest Clin 2007; 59(1): 32-41. ^{, 15}15. Bronte-Tinkew J, Zaslow M, Capps R, Horowitz A, Mcnamara M. Food insecurity works through depression, parenting, and infant feeding to influence overweight and health in toddlers. J Nutr 2007; 137(9): 2160-65.. However, recent findings of a study conducted with the Brazilian child population suggest that a situation of food insecurity does not increase the risk of overweight among the studied children¹⁶16. Kac G, Schlüssel MM, Pérez-Escamilla R, Velásquez-Melendez G, Silva AA. Household food insecurity is not associated with BMI for age or weight for height among Brazilian children aged 0-60 months. PLoS ONE 2012; 7(9): e45747..

Studies that measure the relationship between food insecurity and nutritional status among children are mostly conducted in developed nations, and, therefore, they frequently assess the effect over excessive weight or obesity. There are still only a few investigations in medium or low income countries, where such relationship can be more complex because of several factors, such as social inequity, poverty, among others. Therefore, The objective of this study was to verify the relationship between food insecurity an nutritional status of Brazilian children aged less than five years old, analyzed in the National Demographic and Health Survey (PNDS) of 2006.

Methodology

Data in this study were obtained in the last PNDS survey performed between 2006/07 in Brazil, which aimed at studying maternal and child health of women at reproductive age and children aged less than five years old⁷7. Brasil. Ministério da Saúde. Pesquisa Nacional de Demografia e Saúde da Criança e da Mulher - PNDS 2006. Brasília: Ministério da Saúde; 2008..

This survey included a probability sample with national representativeness and cross-sectional design. Ten sample strata based on the combination of five Brazilian geographic macroregions and on the urban and rural areas were defined in the first stage of the sampling process. In each of these strata, two other stages were selected: primary units, which are the census sectors, and secondary units, which are the private households, with or without occupation, identified within the census sectors. This complex sampling process requires the expansion of the sample with household adjustment inside each census sector. This adjustment, as well as calibration according to estimates of the official Brazilian population from the Brazilian Institute of Geography and Statistics (IBGE)¹⁷17. Instituto Brasileiro de Geografia e Estatística. Pesquisa nacional por amostra de domicílio: 2006. 27th vol. Rio de Janeiro: Instituto Brasileiro de Geografia e Estatística; 2007., published in 2007, considered the losses that took place during data collection and the proportion of women at reproductive age found in each household. More information about this sampling process can be found in the PNDS report⁷7. Brasil. Ministério da Saúde. Pesquisa Nacional de Demografia e Saúde da Criança e da Mulher - PNDS 2006. Brasília: Ministério da Saúde; 2008..

Data were collected in the selected households, by interviewers who were trained to use the instruments containing demographic, socioeconomic and health information of women and children aged less than five years old. The latter included data on lifestyle, nutrition, medication, food security and anthropometry of the interviewees. The collection of anthropometric measures was in accordance with the recommendations by the World Health Organization (WHO)¹⁸18. World Health Organization. Physical Status: the use and interpretation of anthropometry. Report of a WHO Expert Committee. Technical Report Series. n. 854. Geneva: World Health Organization; 1995., and two weight and height measures were obtained for each individual, using the arithmetic mean to calculate the Z score. The weight measure was obtained by using the portable electronic scale by Dayhome^(r), for up to 150 kg and 0.1 kg precision. Among children aged less than two years old, height was obtained by measuring length, with the child lying down, in an infantometer. Among children aged two years old or more and women, the measure was taken in the standing position, in a device called stadiometer. Portable infantometers and stadiometers were developed especially for PNDS - 2006 in the Laboratory of Nutritional Assessment of Populations (LANPOP), of the Nutrition Department of Universidade de São Paulo. The former was 110 cm long and had 0.1 cm precision; the latter was 210 cm long and had 0.1 cm precision, respectively. All of the equipment was calibrated in the beginning and in the end of each work day.

Household food insecurity was defined by the Brazilian Scale of Food Insecurity (EBIA), validated for the Brazilian scenario between 2003 and 2004¹⁸18. World Health Organization. Physical Status: the use and interpretation of anthropometry. Report of a WHO Expert Committee. Technical Report Series. n. 854. Geneva: World Health Organization; 1995.. All of the questions of this scale referred to a reminiscent period of three months prior to the interview, and each affirmative answer received value "1".

For the classification of food security/insecurity, a score was calculated according to the number of positive answers in each item of the scale (1 point for "yes" and 0 point for "no" or "do not know") and to the age composition of the household. For households with no participants aged less than 18 years old, it was only possible to apply eight questions. Therefore, the highest possible score was eight. For households with people aged less than 18 years old, the full questionnaire was applied and accounted for 16 points. The score and cutoff point criteria of EBIA enables the division in 4 categories and 3 levels of intensity: food security (FS), mild, moderate and severe food insecurity, which are distributed according to the presence or absence of people aged less than 18 years old. The validity of the scale and the adaptation of the adopted cutoff points was confirmed by the high internal validity of the scale (Chrombach's α = 0.91)¹⁹19. Perez-Escamilla R, Segall-Correa AM, Maranha LK, Sampaio MFA, Marin-Leon L, Panigassi G. An adapted version of the U.S. Department of Agriculture Food Insecurity module is a valid tool for assessing household food insecurity in Campinas, Brazil. J Nutr 2004; 134(8): 1923-8..

The main exposure of this study was defined by the classification of the interviewed families according to the presence of food insecurity and their different levels of severity. Therefore, mild food insecurity was considered when households accounted from 1 to 5 points; moderate, for households that had 6 to 10 points; and severe food insecurity for 11 to 16 points. The situation of food security was defined for those families with negative answers for all of the questions.

In this study, the outcome was defined based on the height-for-age, weight-for-age and weight-for-height indices, assessed as Z score by means of WHO reference curves²⁰20. World Health Organization. WHO Multicentre Growth Reference Study Group. WHO child growth standards: length/height-for-age, weight-for-age, weight-forlength, weight-for-height and body mass index-for-age: methods and development. Geneva: World Health Organization, 2006.. The distribution of Z score means of the three indices according to demographic and socioeconomic variables was observed, with the objective of detecting differences between groups, especially concerning those differences that would not be noticed in case the variables were in dichotomous format. Therefore, extreme values were ruled out (lower than Z scores -5 and -6 higher than Z scores +5 and +6 for weight and height, respectively), according to WHO¹⁸18. World Health Organization. Physical Status: the use and interpretation of anthropometry. Report of a WHO Expert Committee. Technical Report Series. n. 854. Geneva: World Health Organization; 1995..

The other variables used in this analysis were: household macroregion (North, Northeast, Southeast, South, Center-West), situation of the household (urban, rural), receiving the Bolsa Família Program (PBF), number of people in the household (2 to 4, 5 or more), household income quartiles (< 340, 350 - 520, 525 - 980, > 1000 reais in the month prior to the interview), age of the mother (15 - 19, 20 - 35, 36 - 49 years old), skin color of the mother (white, black/mulatto, other), child's age (0 - 12, 13 - 24, 25 - 36, 37 - 48, 49 - 59 months) and gender (male, female).

Descriptive analyses include the distribution of sociodemographic variables (gender, household macroregion, situation of the household, household income quartiles, age of the mother, skin color of the mother, and child's age) and food insecurity according to Z scores means for height-for-age, weight-for-age and weight-for-height. Linear regression was used in the analysis to assess the crude and adjusted effect of food insecurity over the Z score of the three nutritional indices. Confusion factors were those variables with p < 0.2 in the crude analysis. Therefore, results are presented by regression coefficient (beta) and its respective 95% confidence intervals (95%CI). Analysis were performed in the statistical software Stata, version 11.0, and all of the estimates were pondered, considering the design effect, as well as calibration according to the estimates of the Brazilian population, by means of the svy command in Stata.

This study presents no real, potential or apparent conflict of interest by none of the authors, and was approved by the Research Ethics Committee of the Medical School of Universidade Federal de Pelotas.

Results

The sample of PNDS 2006/07 was comprised of 15,575 women, aged from 15 to 49 years old, and 5,461 children aged less than five years old. The results in this study refer to 4,817 children (about 88% of the original sample) whose information about household, including family food insecurity, was available. Our of these 4,817 children, 4,410 had information about the height-for-age index, 4,496 had information about weight-for-age index, and 4,374 had information on weight-for-height index.

The distribution of this population, considering the sample design, reveals that almost half of them lived in the Southeast region of the country (42%), and most of them lived in the urban zone (81%). In relation to PBF, about 1 out of 4 families received this benefit, and 38% of the studied children lived in households with 5 or more inhabitants. As to maternal age, while 11% of the children had adolescent mothers (15 to 19 years old), 76% had mothers aged from 20 to 35 years old, and 13% had mothers aged more than 35 years old, and more than half of the mothers reported their skin color as nonwhite.

The nutritional status classification shows that the prevalence of height-for-age deficit was of 7.6% (95%CI 6.7 - 8.5) among the children included in this study. For weight-for-age and weight-for-height deficits, these proportions did not reach 2.5%, which would be expected in population with normal distribution. On the other hand, 6.6% (95%CI 5.5 - 7.8) of the children were classified with excessive weight in relation to height. Concerning the household food situation, it was observed that half of the children (45.6%) lived in a household with some level of food insecurity.

The mean values of the Z scores for height-for-age, weight-for-age and weight-for-height were, respectively, -0.31 (± 0.04), 0.12 (± 0.03) and 0.40 (± 0.03). The means for these three indices in relation to exposure variables are presented in Table 1.

It is possible to observe that the mean Z score for height-for-age was significantly lower among children living in the North region of the country. On the other hand, higher Z score means for this index were found in children who did not receive PBH, living in households with two to hour inhabitants with higher income. Besides, the analysis suggests that female children present with higher Z score mean for height-for-age (p = 0.05). With regard to children's age, a positive mean, close to zero, was observed in those aged up to 12 months old. In relation to older children, these means were negative. Concerning food insecurity, negative Z score means were observed for height-for-age, regardless of the classification level. However, for children living in households classified as secure, this mean was significantly higher when compared to the other groups (Table 1).

In Table 1, it is observed that the Z score mean for weight-for-age was equally lower among children in the North region of the country, those receiving PBF and the ones living in households with more inhabitants (five or more). Inversely, these means were significantly higher for younger children, living in households with food security and coming from families with higher income.

With regard to weight-for-height, unlike what has been observed for height-for-age, Z score means were positive, regardless of demographic, socioeconomic of food insecurity level characteristics. Children coming from more developed regions of the country (South and Southeast) and who did not receive the PBF presented significantly higher means for this index. Besides, it was observed that the higher the number of people living in the same household as the child, the lower the income and the more severe the food insecurity situation, therefore, the Z score mean for weight-for-height was lower (Table 1).

In the regression analysis, it was observed that the more severe the food insecurity level, the lower the Z score of the three nutritional indices, being height-for-age the one that mostly suffers negative influence from the food situation. However, it was observed that only the height-for-age index was associated with the food insecurity situation after the control for confusion factors included in this analysis (Table 2).

Discussion

The main result of this study refers to the fact that children suffering from some level of food insecurity have worse nutritional indices. After adjustment for confusion factors, it was observed that only the height-for-age index was still affected by the food insecurity level experienced by the child. Such result is in accordance with literature, since depending on the level of development of a nation, food insecurity can be related to nutritional status, both towards deficit, in the case of medium or low income countries, and towards excessive weight, in developed nations¹²12. Hernádez LO, Gutiérrez MNA, Pérez AEN, Fonseca NP, Gómez YR. Em escolares de la Ciudad de México lá inseguridad alimentaria se associó positivamente com el sobrepeso. Rev Invest Clin 2007; 59(1): 32-41.

13. Hackett M, Melgar-Quiñonez H, Álvarez MC. Household food insecurity associated with stunting and underweight among preschool children in Antioquia, Colombia. Rev Panam Salud Publica 2009; 25(6): 506-10.

14. Reis M. Food insecurity and the relationship between household income and children's health and nutrition in Brazil. Health Econ 2011; 21(4): 405-27.

15. Bronte-Tinkew J, Zaslow M, Capps R, Horowitz A, Mcnamara M. Food insecurity works through depression, parenting, and infant feeding to influence overweight and health in toddlers. J Nutr 2007; 137(9): 2160-65. ^{- 16}16. Kac G, Schlüssel MM, Pérez-Escamilla R, Velásquez-Melendez G, Silva AA. Household food insecurity is not associated with BMI for age or weight for height among Brazilian children aged 0-60 months. PLoS ONE 2012; 7(9): e45747..

Global data about nutritional indices of children aged less than five years old show that the mean for height-for-age decreases with age, and it is always lower when compared to weight-for-age and weight-for-height indices²¹21. Victora CG, de Onis M, Hallal PC, Blössner M, Shrimpton R. Worldwide timing of growth faltering: revisiting implications for interventions. Pediatrics 2010; 125(3): e473-80.. Likewise, the height-for-age mean in this study was lower (-0.31) than weight-for-age (0.12) and weight-for-height means (0.40), and also decreased with age.

The height mean was below expected for all of the analyzed children, since a mean Z score value of zero would be expected from a normal distribution population. However, it was observed that such values were even lower for those living with some level of food insecurity. Besides, after the adjusted analysis, food insecurity remained negatively related to their height, together with income and, to a lower degree, to the household macroregion (data not shown). This shows that this relationship has been connected to the socioeconomic level of the children, since these determiners are closely related.

Despite the low prevalence of excessive weight, with regard to weight-for-height it was observed that the mean values of this index were high, regardless of the food insecurity situation. However, these values were higher in the group living with food security, and food insecurity did not have any influence on this index.

This situation, in which the height mean was below expected and weight mean was above expected, suggests that excess weight problems can be present in these children. In the last Survey of Household Budgets (POF) of 2008/09, it was mainly observed in children aged from 5 to 9 years old, once about one third of them presented with excessive weight²²22. Instituto Brasileiro de Geografia e Estatística. Pesquisa de Orçamentos Familiares 2008-2009: Antropometria e estado nutricional de crianças, adolescentes e adultos no Brasil. Rio de Janeiro: Instituto Brasileiro de Geografia e Estatística; 2010..

The effect of food insecurity on nutritional status has been investigated by other national studies that used the PNDS database¹⁴14. Reis M. Food insecurity and the relationship between household income and children's health and nutrition in Brazil. Health Econ 2011; 21(4): 405-27. ^{, 16}16. Kac G, Schlüssel MM, Pérez-Escamilla R, Velásquez-Melendez G, Silva AA. Household food insecurity is not associated with BMI for age or weight for height among Brazilian children aged 0-60 months. PLoS ONE 2012; 7(9): e45747. ^{, 23}23. Velásquez-Melendez G, Schlüssel MM, Brito AS, Silva AAM, Lopes-Filho JD, Kac G. Mild but not light or severe food insecurity is associated with obesity among Brazilian women. J Nutr 2011; 141(5): 898-902..

The first study indicated that children with food insecurity can show worse anthropometric indicators. However, there was no comparison between the means of nutritional indices of those living with food insecurity and the means of the individuals who did not experience such situation, and the main objective of the study was to investigate the association between food insecurity and health and nutrition indicators of children¹⁴14. Reis M. Food insecurity and the relationship between household income and children's health and nutrition in Brazil. Health Econ 2011; 21(4): 405-27.. The other two investigations aimed at observing the relationship between food insecurity and excessive weight among children¹⁶16. Kac G, Schlüssel MM, Pérez-Escamilla R, Velásquez-Melendez G, Silva AA. Household food insecurity is not associated with BMI for age or weight for height among Brazilian children aged 0-60 months. PLoS ONE 2012; 7(9): e45747. and women²³23. Velásquez-Melendez G, Schlüssel MM, Brito AS, Silva AAM, Lopes-Filho JD, Kac G. Mild but not light or severe food insecurity is associated with obesity among Brazilian women. J Nutr 2011; 141(5): 898-902.. The first one also analyzed the child population of PNDS and observed similar results to those of this study, and found no relationship between these two health indicators. However, the authors did not present results for the height-for-age index, and included different variables in relation to this study in the analysis model. On the other hand, the study conducted with women²³23. Velásquez-Melendez G, Schlüssel MM, Brito AS, Silva AAM, Lopes-Filho JD, Kac G. Mild but not light or severe food insecurity is associated with obesity among Brazilian women. J Nutr 2011; 141(5): 898-902. suggested that moderate food insecurity can lead to excessive weight.

Considering international studies that assessed the relationship between food insecurity and nutritional status, it is observed that the results are not similar when considering the development stage of the location of the study. Therefore, in high income countries, most studies relates food insecurity with overweight/obesity, since in these places the frequency of excessive weight among children is twice as high as the one found in developing countries, so problems related to nutritional deficit are rare¹⁰10. Rose D, Bordor JN. Household food insecurity and overweight status in young school children: results from the Early Childhood Longitudinal Study. Pediatrics. 2006; 117(2): 464-73. ^{, 11}11. Gundersen C, Garasky S, Lohman BJ. Food insecurity is not associated with childhood obesity as assessed using multiple measures of obesity. J Nutr 2009; 139(6): 1173-8. ^{, 24}24. Kaiser LL, Melgar-Quiñonez HR, Lamp CL, Johns MC, Sutherlin JM, Harwood JO. Food security and nutritional outcomes of preschool-age Mexican-American children. J Am Diet Assoc 2002; 102(7): 924-9. ^{, 25}25. Casey PH, Simpson PM, Gosset JM, Bogle ML, Champagne CM, Cornell C et al. The association child and household food insecurity with childhood overweight status. Pediatrics 2006; 118(5): 1406-13.. These studies present the effects of mild, moderate or severe food insecurity on the prevalence of excessive weight, showing that such condition is sometimes more common among children with food insecurity, and sometimes more common among those who do not experience this situation. In this study, in which the prevalence of excessive weight for height was lower in comparison to the aforementioned studies (6.6%), it was observed that children with severe food insecurity had weight-for-height means significantly lower in comparison to children with food security. Besides, weight-for-height means were always higher in groups with of higher socioeconomic level (children in the urban zone, without PBH, in households with fewer people and higher income), which is opposed to the hypothesis of association between these two health conditions.

With regard to low and medium income countries, most studies associate the situation of household food insecurity to the possible nutritional deficits it can cause¹³13. Hackett M, Melgar-Quiñonez H, Álvarez MC. Household food insecurity associated with stunting and underweight among preschool children in Antioquia, Colombia. Rev Panam Salud Publica 2009; 25(6): 506-10. ^{, 14}14. Reis M. Food insecurity and the relationship between household income and children's health and nutrition in Brazil. Health Econ 2011; 21(4): 405-27. ^{, 26}26. Bolzán A, Mercer R. Seguridad alimentaria y retardo crónico del crecimiento en niños pobres del norte argentino. Arch Argent Pediatr 2009; 107(3): 221-8.. In this study, it was observed that food insecurity is negatively related to all of the nutritional indices, especially the height-for-age index. Besides, regardless of the food security situation lived by the household, for children older than 12 months old, the means of this index were always negative, reaching almost -1 Z score among those with moderate and severe insecurity. Similarly, studies conducted in different South America countries showed that children in households with food insecurity had more prevalence of height deficit¹³13. Hackett M, Melgar-Quiñonez H, Álvarez MC. Household food insecurity associated with stunting and underweight among preschool children in Antioquia, Colombia. Rev Panam Salud Publica 2009; 25(6): 506-10. ^{, 26}26. Bolzán A, Mercer R. Seguridad alimentaria y retardo crónico del crecimiento en niños pobres del norte argentino. Arch Argent Pediatr 2009; 107(3): 221-8.. However, none of the studies conducted in these locations has national representativeness, thus not presenting a population overview of this relationship.

There are many ways in which food insecurity influences child nutritional status, such as child's age, skin color, family income, among other determiners. However, food consumption is the most important mediator, being an essential component of this relationship²⁷27. Dinour LM, Bergen D, Yeh MC. The food insecurity-obesity paradox: a review of the literature and the role food stamps may play. J Am Diet Assoc 2007; 107(11): 1952-61.. Even though data on child food consumption are available in the database, it was not part of the study's scope to assess the food consumption of the analyzed children. However, evidence suggests differences among those living in good insecurity according to the household location. Studies conducted in high income countries reported that children living with food insecurity present more consumption of energy, sugar and fat and less consumption of fruits, meat and dairy products²⁸28. Matheson DM, Varady J, Varady A, Killen JD. Household food security and nutritional status of Hispanic children in the fifth grade. Am J Clin Nutr 2002; 76(1): 210-7. ^{, 29}29. Oh SY, Hong MJ. Food insecurity is associated with dietary intake and body size of Korean children from low-income families in urban areas. Eur J Clin Nutr 2003; 57(12): 1598-604.. Likewise, a nationally representative study about food consumption showed that Brazilian children, despite living in a country going through a long nutritional transition process, presented higher intake of sugar and fat and lower intake of fruits, vegetables and meat³⁰30. Bortolini GA, Gubert MB, Santos LMP. Consumo alimentar entre crianças brasileiras com idade de 6 a 59 meses. Cad Saúde Pública 2012; 28(9): 1759-71.. Even though the food consumption of Brazilian children is similar to that of children in developed countries, the difference in the relationship of food insecurity with overweight/obesity can be explained by the fact that, in Brazil, obesity levels began to increase recently, and still affect richer children, while in developed countries the problem of child obesity is older, reaching all social levels.

The main advantage of this study refers to the complex design of the sample selection that enabled the evaluation of the food insecurity effect on the nutritional indices of children aged less than five years old living in the five Brazilian macroregions, both in the urban and rural contexts. The methods applied by PNDS⁷7. Brasil. Ministério da Saúde. Pesquisa Nacional de Demografia e Saúde da Criança e da Mulher - PNDS 2006. Brasília: Ministério da Saúde; 2008., like the standardization of data collection, including a rigorous training of the interviewers and the quality control during the period of field work, can be considered as other positive aspects of this study. On the other hand, the use of EBIA reflects a relative measure of the situation experienced by all of the individuals living in the same household; therefore, it is not an individual measure of food insecurity. However, despite this limitation, it is known that when a household experiences this situation, consequently, all of the inhabitants are affected⁹9. Bickel GW, Nord M, Price C, Hamilton W, Cook J. Measuring food security in the United States. Guide to measuring household food security. Revised 2000. Alexandria: United States Department of Agriculture; 2000..

To understand the relationship of food insecurity with child nutritional status is very important to develop policies and health and nutrition programs that can fight both food insecurity and nutritional issues. In this study, it was observed that the height-for-age mean was below expected among children with medium or severe food insecurity. These findings assume that these children are more exposed to the risk of malnourishment, which has serious consequences for their physical and mental development. Some studies report that problems related to food insecurity are not only nutritional, since there can be emotional, behavioral and mental development problems³¹31. Belsky DW, Moffitt TE, Arseneault L, Melchior M, Caspi A. Context and sequelae of food insecurity in children's development. Am J Epidemiol 2010; 172(7): 809-18. ^{, 32}32. Zaslow M, Bronte-Tinkew J, Capps R, Horowitz A, Moore KA, Weinstein D. Food security during infancy: implications for attachment and mental proficiency in toddlerhood. Matern Child Health J 2009; 13(1): 66-80.. Such findings confirm the importance to promote proper nourishment in terms of quantity and quality, not only to prevent nutritional disorders, but also for the children to reach their full growth and development potential.

Conclusion

Food insecurity has been negatively related to the height-for-age index at all ages, even controlling for some demographic and socioeconomic factors, such as household location, income, number of inhabitants of the household, skin color of the mother, among others. However, this relationship seems to be connected to the socioeconomic level of these Brazilian children, being strongly connected to the monthly income of the family and location of the household.

References

Publication Dates

History