Relationship between pregestational nutritional status and type of processing of foods consumed by high-risk pregnant women

Abstract Objectives: to relate pregestational nutritional status, maternal age and number of pregnancies to the distribution of macronutrients and micronutrients according to the type of processing offoods consumed by high-risk pregnant women. Methods: a retrospective cross-sectional study was carried out with data from medical records of 200 pregnant women served by a public outpatient clinic in Rio Grande do Sul from 2014 to 2016. Results: the mean percentages of lipids, monounsaturated fatty acids, polyunsaturated fatty acids and sodium intake were higher among ultra-processed foods. There was a significant inverse correlation between maternal age and total calorie intake (p=0.003) and percentage of carbohydrates (p=0.005) and proteins (p=0.037) from ultra-processed foods. There was also a significant association between pregestational nutritional status and total calorie intake (p=0.018) and percentage of carbohydrates (p=0.048) from ultra-processed foods. Conclusions: the mean percentages of lipids, monounsaturated fatty acids, polyunsaturated fatty acids and sodium intake were higher among ultra-processed foods. It was observed that the older the maternal age of high-risk pregnant women, the lower the intake of total calories and percentages of carbohydrates and proteins from ultra-processed foods. It was also observed that pregestational nutritional status was significantly associated with the intake of total calories and percentage of carbohydrates from ultra-processed foods.


Introduction
Pregnancy is the period in which nutritional needs are increased due to physiological adjustments in the maternal organism and fetal development. Therefore, adequate nutrient availability and a balanced diet are essential for this phase of life. 1 During pregnancy, both mother and the fetus may face health risks that can lead this phase to become a risk pregnancy 2 in which the most common consequences are preterm birth, prolonged pregnancy, preeclampsia and eclampsia, hemorrhages, gestational diabetes, cervical insufficiency, and even death of the fetus. 3 Pregnant women's inadequate dietary habits potentiate risks during pregnancy 4 and have a strong impact on obstetric outcomes and clinical characteristics of the newborn. 5 Therefore, the expectant mother needs to be aware of her pregestational nutritional status, her food intake and, above all, the quality of the food sheeats. 6 The Dietary Guidelines for the Brazilian Population classified food according to the type of processing, with natural foods being those obtained from nature that do not undergo any type of processing. Minimally processed foods are natural foods that undergo some type of processing for cleaning, removal of unwanted parts, grinding, drying and pasteurization, among others. Processed foods are natural or minimally processed foods that contain additives (sugar, salt or some substance used in cooking) to enhance flavor or increase durability. Ultra-processed foods are foods that undergo several types of processing and that are added to industrial formulations. 7 The daily intake of natural and minimally processed foods is related to disease prevention. 8 On the other hand, the intake of processed and ultraprocessed foods is related to the onset of chronic diseases given the changes in their nutritional composition. This explains the importance of having pregnant women prioritize natural foods and reduce the intake of processed foods and avoid ultraprocessed foods. 9 Healthy habits and choices, in addition to minimizing risks during pregnancy, improve the quality of fetal development and maternal nutritional status. 10 Thus, given the scarcity of publications addressing the relationship between pregnant women's nutritional status and the type of processing of the food they eat, this study aimed to relate pregestational nutritional status, maternal age and number of pregnancies to the distribution of macronutrients and micronutrients according to the type of processing of foods consumed by high-risk pregnant women.

Methods
This is a quantitative retrospective cross-sectional study of data from medical records of 300 high-risk pregnant women. The study included high-risk pregnant women aged 15 to 45 years who were referred from 2014 to 2016 for the treatment of comorbidities such as hypertension, diabetes mellitus, hypothyroidism, toxoplasmosis and obesity in a public outpatient clinic located in the countryside of Rio Grande do Sul. The study excluded 100 medical records that did not present complete data on a 24hour dietary recall of a single day and information on pregestational nutritional status, age, and number of pregnancies. The pregestational nutritional status was determined using the body mass index (BMI) and its classification was based on the 1998 World Health Organization (WHO) standards, namely: malnutrition (<18.5 kg/m²), normal weight (≥18.5 and ≤24.9 kg/m²), overweight (≥ 25.0 and ≤ 29.9 kg/m²), class I obesity (≥30.0 and ≤34.9 kg/m²), class II obesity (≥35.0 and ≤39.9 kg/m²) and class III obesity (≥40.0 kg/m²). 11 The 24-hour dietary recalls of the pregnant women were analyzed using the 2008 DietWin ® software and total calories and intake of carbohydrates, proteins, lipids, sodium, and monounsaturated, polyunsaturated and saturated fats from all the foods consumed were measured. After that, the calories and percentages of each macronutrient and each micronutrient mentioned above were calculated according to the classification of each food described in the Dietary Guidelines for the Brazilian Population, which categorizes foods into: natural, minimally processed, processed and ultraprocessed. 7 Statistical analysis was performed using the Kruskal-Wallis test and Pearson's correlation analysis. Results were considered significant at a maximum significance threshold of 5%. The software used for the analyses was the SPSS (Statistical Package for the Social Sciences) version 22.0.

Results
The mean age of the pregnant women was 29.64 ± 6.82, the mean number of children was 1.92 ± 1.04, Fernandes DC et al.

Processing of foods consumed by high-risk pregnant women
and the mean number of pregnancies was 2.49 ± 1.5. With regard to the percentages of total calories from the different types of processing of the foods consumed by high-risk pregnant women, 47.21% were from natural/minimally processed foods, 38.07% were from ultra-processed foods, and 14.72% were from processed foods.
According to Table 1, there were higher means of total calories and percentages of carbohydrates, proteins and saturated fats from natural/minimally processed foods followed by ultra-processed and processed foods. The mean percentages of lipids and monounsaturated and polyunsaturated fats were higher among ultra-processed foods, followed by natural/minimally processed foods and processed foods. In regard to the percentage of sodium, there was a higher mean among ultra-processed foods, followed by processed foods and natural/minimally processed foods.
There was a direct correlation ( Table 2) between age and percentage of carbohydrates from natural/minimally processed foods (p=0.013). There was also a significant inverse relationship between age and intake of total calories (p=0.003) and percentages of carbohydrates (p=0.005) and proteins (p=0.037) from ultra-processed foods.
There was also a correlation between pregestational nutritional status and percentage of protein from natural/minimally processed foods (p=0.021). The percentage of intake of protein from natural/minimally processed foods in Class III obese pregnant women was significantly lower when compared with overweight and class I and II obese pregnant women. There was also an association of pregestational nutritional status with total calorie intake (p=0.018) and percentage of carbohydrates (p=0.048) from ultra-processed foods. Total calorie intake and percentage of carbohydrates from ultraprocessed foods were significantly higher among high-risk pregnant women with class III obesity and normal weight when compared with overweight and class II obese pregnant women. Additionally, overweight and class II obese high-risk pregnant women exhibited lowers percentages of protein from ultraprocessed foods (p=0.024) when compared with those with normal weight or class I and III obesity ( Table 3).
Class III obese pregnant women presented lower percentages of intake of monounsaturated (p=0.040) and saturated (p=0.034) fats from natural/minimally processed foods when compared with class II obese pregnant women (Table 4).
There was an association between pregestational nutritional status and percentage of sodium from natural/minimally processed foods (p=0.050). Class III obese pregnant women presented significantly lower percentages of intake of sodium from natural/minimally processed foods when compared with overweight or class I and II obese pregnant women (Table 5).

Discussion
The consumption of ultra-processed foods in the present study represented 38.07% of the total calories consumed by high-risk pregnant women. This percentage is lower than that found in a study carried out with young adults in the city of Pelotas, Rio Grande do Sul, which showed a consumption of 51.20%, 12 and higher than that found in a study carried out with individuals from the 2008 and 2009 Family Budget Surveys in São Paulo, which demonstrated a consumption of 21.5% of total calories. 13 This finding shows the increasing influence of ultraprocessed products on Brazilian food 14 and hence the need to develop strategies to encourage the consumption by the entire population, including pregnant women, of natural/minimally processed foods. 15 The present study demonstrated that the older the maternal age of high-risk pregnant women, the lower the intake of total calories and the percentages of carbohydrates and proteins from ultra-processed foods. This finding agrees with other studies that have shown that older pregnant women tend to eat less unhealthy snacks and fast food, 16,17 which are meals known to increase overweight and obesity 18 as they contain a large amount of sugar, fat and sodium. 19 In the present study, class III obese high-risk pregnant women presented lower percentages of intake of protein from natural/minimally processed foods when compared with overweight or class I and II obese pregnant women. The consumption of ultraprocessed foods was responsible for the second highest mean rate of total calories and percentages of carbohydrates, proteins and saturated fats consumed. Consumption of ultra-processed foods during pregnancy results in unfavorable consequences for both mother and the fetus, including the woman's excessive weight gain during pregnancy and an increase in the newborn's body fat. It is important to emphasize that the permanence of such excess weight may contribute to the development of associated comorbidities, such as type II diabetes, cardiovascular disease, mental health problems and cancer. 20 Maternal food consumption during pregnancy is Table 1 Characterization of total calorie intake and percentage of carbohydrates, protein, lipids, monounsaturated fatty acids, polyunsaturated fatty acids, saturated fatty acids and sodium from natural/minimally processed, processed and ultraprocessed foods among high-risk pregnant women.  Table 2 Association of number of pregnancies, age and pregestational nutritional status with total calorie intake and percentage of carbohydrates, protein, lipids, monounsaturated fatty acids, polyunsaturated fatty acids, saturated fatty acids and sodium from natural/minimally processed, processed and ultra-processed foods among high-risk pregnant women.  Table 2 Association of number of pregnancies, age and pregestational nutritional status with total calorie intake and percentage of carbohydrates, protein, lipids, monounsaturated fatty acids, polyunsaturated fatty acids, saturated fatty acids and sodium from natural/minimally processed, processed and ultra-processed foods among high-risk pregnant women.

Table 3
Association of pregestational nutritional status with total calorie intake and percentage of carbohydrates and protein from natural/minimally processed, processed and ultra-processed foods among high-risk pregnant women.  Table 3 Association of pregestational nutritional status with total calorie intake and percentage of carbohydrates and protein from natural/minimally processed, processed and ultra-processed foods among high-risk pregnant women.  Table 4 Association of pregestational nutritional status with percentage of intake of lipids, monounsaturated fatty acids, polyunsaturated fatty acids and saturated fatty acids from natural/minimally processed, processed and ultra-processed foods among high-risk pregnant women.  Table 4 Association of pregestational nutritional status with percentage of intake of lipids, monounsaturated fatty acids, polyunsaturated fatty acids and saturated fatty acids from natural/minimally processed, processed and ultra-processed foods among high-risk pregnant women.  concluded Table 5 Association of pregestational nutritional status with percentage of intake of sodium from natural/minimally processed, processed and ultra-processed foods among high-risk pregnant women. responsible for promoting the neurodevelopment of children, which reinforces the importance of having a healthy lifestyle before pregnancy even begins. 21 Thus, prenatal care is of fundamental importance to encourage, guide and motivate pregnant women by promoting healthy eating habits 22 and by monitoring the health of the mother and the fetus. 21 In a study on the healthy eating index of Brazilian pregnant women, the overall dietary intake of pregnant women was assessed based on three food groups(vegetables, fruits and beans and other protein-rich vegetables), two ratios (red/white meat and polyunsaturated/saturated fat) and five nutrients (fiber, trans fat, calcium, folate and iron) and it was found that most of them lacked dietary intake improvements, thus showing the need to deliver food education at this stage of life. 23 In the present study, class III obese and normal weight high-risk pregnant women presented a higher intake of total calories and higher percentages of carbohydrates from ultra-processed foods when compared with overweight and class II obese pregnant women, that is, the consumption of ultraprocessed foods may not be related only to the nutritional status of pregnant women. Social mobility improvement, lifestyle and high levels of education are some of the factors that suggest a greater access to ultra-processed foods; in addition, these same factors can influence individuals' physical inactivity. 12 Overweight and class II obese high-risk pregnant women consumed significantly lower percentages of protein from ultra-processed foods compared with normal weight and class I and III obese pregnant women. According to results found in the present study, this relationship occurred because overweight and class II obese high-risk pregnant women consumed higher percentages of protein from natural/minimally processed foods.

Variables
It was also observed that class III obese pregnant women consumed significantly lower percentages of monounsaturated and saturated fatty acids from in natura/minimally processed foods compared withclass II obese pregnant women. This finding indicates that class III obese pregnant women consumed higher percentages of saturated and monounsaturated fatty acids from ultra-processed foods. Therefore, interventions and actions should be carried out during prenatal care in order to promote and encourage the consumption of natural foods, as well as reinforce the importance of healthy habits 24 and, mainly, inform pregnant women about how much their nutritional status influences the baby's health. Pregnant women who have a BMI that suggests obesity tend to have greater complications during childbirth and maternal complications such as gestational diabetes and hypertensive syndrome and are more likely to experience perinatal complications such as macrosomia and low Apgar score in the first minute. 25 The present study demonstrated that class III obese pregnant women exhibited a significantly lower percentage of sodium intake from natural/minimally processed foods when compared with overweight and class I and II obese pregnant women, i.e., class III obese pregnant women consumed higher percentages of sodium from ultraprocessed foods. It was also possible to identify that the overall mean percentages of lipids, monounsaturated fatty acids, polyunsaturated fatty acids and sodium were higher among ultra-processed foods, which may be related to the strong influence of marketing on the eating habits of the population 14 and to the fact that these foods are well accepted due to their taste, have a long shelf life and are practical, as they can be consumed at any time and place. 26 Therefore, nutritional follow-up is essential for the definition of a diet that meets nutritional demands. 2 During pregnancy, there is a greater predisposition to positive changes in maternal food choices,  Table 5 Association of pregestational nutritional status with percentage of intake of sodium from natural/minimally processed, processed and ultra-processed foods among high-risk pregnant women.

Variables
BMI n X ± SD p % total sodium ultra-processed  27 A cohort study in Rio de Janeiro analyzed the type of food processing and changes in food consumption before and during pregnancy and concluded that the consumption of ultra-processed foods decreased and the consumption of natural/minimally processed foods increased from the period before pregnancy and throughout pregnancy, thus emphasizing the importance of nutritional follow-up during pregnancy. 28 Despite that, the vast majority of women continue to consume foods rich in sugar, saturated fat and sodium during pregnancy. 19 Such habits may be related to the increase in overweight and obesity 5 as well as heighten the predisposition of chronic diseases 29 such as diabetes mellitus, which is associated with high rates of perinatal morbidity and mortality. 3 A simple way to reduce the chances of developing chronic diseases and improve maternal and neonatal health in the short and long term is -in addition to getting prenatal care -to reduce the consumption of ultra-processed foods. 19 The consumption of this kind of food should be reduced because they are rich in saturated fat, trans fat and free sugar and poor in fiber and protein when compared with natural/minimally processed foods. 9,30 A diet based on natural and minimally processed foods may even prevent diseases. 8 One of the limitations of this study may have been the use of a single dietary recall from each high-risk pregnant woman. In addition, the dietary recall was based on secondary data and hence there may have been underestimation or overestimation of habitual consumption. This study is expected to contribute to the improvement of the care of pregnant women and to the evolution of scientific knowledge, thus improving health education and strength-ening current public policies in the field of maternal and child health.
In the present study, the mean percentages of intake of lipids, monounsaturated fatty acids, polyunsaturated fatty acids and sodium were higher among ultra-processed foods. It was also observed that the older the maternal age of high-risk pregnant women, the lower the intake of total calories and the percentages of carbohydrates and proteins from ultra-processed foods. Finally, it was observed that pregestational nutritional status is significantly associated with the intake of total calories and percentage of carbohydrates from ultra-processed foods.
Thus, the study confirmed that the consumption of ultra-processed foods is present among high-risk pregnant women, which makes it necessary to develop nutrition education actions and strengthen existing public policies in the field of maternal and child health in order to raise women's awareness of how much their food consumption and habits may affect their children's lives in the short and long term.

Author's contribuition
Fernandes DC was responsible for the conception of the study, the selection of the articles to be included within the manuscript, for the organization, data interpretation and for the writing of the article. Carreno I e Silva AA contributed with the final revision of the manuscript. Guerra TB helped with the typing of the database. Adami FS contributed with the conception of the study, data interpretation, revision of the writing and was responsible by the exchange of correspondence. All authors approved the final version of the manuscript.