| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Department of Human Nutrition, Centro de Investigación en Alimentación y Desarrollo, A.C. Hermosillo, Sonora
Public Health Research Branch, Instituto Nacional de Perinatología, México City, MEXICO
Address correspondence to: Dr. Graciela Caire-Juvera, Centro de Investigación en Alimentación y Desarrollo, A.C. Hermosillo, P.O. Box 1735, Sonora, MEXICO. E-mail: gcaire{at}cascabel.ciad.mx
 |
ABSTRACT |
|---|
 TOP ABSTRACT INTRODUCTIONMATERIALS AND METHODSRESULTSCONCLUSIONSACKNOWLEDGMENTSREFERENCES |
|---|
Methods: A total of 60 women were studied: 41 from Northwest and 19 from Central Mexico, 33 adolescent and 27 adult women. Data were collected through two quantitative 24 h recalls. Two more recalls were used in a sub sample to calculate the coefficient of variation of intakes. Menus were based on the consumption frequency of foods.
Results: The mean energy intake of the adolescent women (2354 ± 1199 kcal) and those of Central Mexico (1690 ± 981 kcal) was lower than the recommendations. Zinc, calcium, vitamin E, C and folate were inadequate (55 to 85% prevalence of inadequacy). Energy, dietary fiber, sodium, potassium, iron and folate intakes were higher (P < 0.05) in Northwest Mexico. Northwestern women consumed less variety of vegetables or fruits compared to Mexico City region women. Wheat tortillas and beans were from Northwestern but not from the Mexico City region diet.
Conclusions: The energy and nutrient intakes of women were different by regional hospital and not by age. Education about the importance of the maternal diet during lactation should be directed toward increasing consumption of foods rich in micronutrients.
Key words: nutrient intake, dietary patterns, macronutrients, micronutrients, lactating women
|
INTRODUCTION |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSCONCLUSIONSACKNOWLEDGMENTSREFERENCES |
|---|
Consideration should be given to the fact that two of the major factors that contribute to the nutritional status of the exclusively breastfed infant are nutrient stores, especially those accumulated in utero, and the amount and bio-availability of nutrients supplied by human milk [2]. Maternal nutrition during pregnancy and lactation plays an important role on the overall health of the infant and in the adulthood. Small babies at birth and during infancy are at an increased risk of developing coronary heart disease and related disorders later in life [3]. Nutritional recommendations state that women who are breastfeeding should increase their energy and nutrient intakes to levels above those of non pregnant, non lactating women [4–6].
There are few published studies on the dietary intake of healthy lactating women in Mexico [7,8]. Regional differences in socioeconomic status and living conditions of Mexican population across the country make comparisons among Northwestern, Central and Southeastern regions of importance for intervention purposes [9]. In the last National Nutrition Survey conducted in Mexico [7], dietetic information was gathered on 4200 women, from which 8% were lactating. Results obtained by the 24 h recall technique showed important micronutrient deficiencies in the diet (Vitamin A, Vitamin C, folate, iron, zinc, calcium). The ingestion of energy, fat, folate and iron were greater in the North Region compared to Mexico City. In the mentioned survey anthropometric information was obtained from 18,311 women at the national level, 60% of the women in the North Region compared to 52% of women in Mexico City were overweight or obese. A study by Valencia et al. [8] on 505 people from northwest Mexico (6.3% pregnant and lactating women together), showed that 40% of the population had low consumption of micronutrients such as vitamin A and C and high intake of energy from fat (36% of the total intake).
This paper presents the results of a dietary survey undertaken to evaluate the energy and nutrient intake as well as dietary patterns, of two groups of Mexican lactating women exclusively breastfeeding within the first month postpartum. The associations between maternal age, region and women's intakes were evaluated.
|
MATERIALS AND METHODS |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSCONCLUSIONSACKNOWLEDGMENTSREFERENCES |
|---|
Losses to follow up were high in the Northwest region, i.e., 46% of the original cohort gave formula feeding to their infants on the first month. Mothers who smoked, whose children had a low birth weight or who were not exclusively breastfeeding were excluded because these factors are related to both maternal nutrition and lactation.
Socioeconomic Status
Socioeconomic indicators were collected at the first interview in the households, and they included income, house material, family constitution, educational level and access to public services. All the women were of low socioeconomic status, which included all the single and economically dependent women, and incomes of 90.0 to 200.0 dollars a month at the time of study.
Data Collection
Qualified interviewers collected the data through home visits; demographic data included age, level of maternal education and socioeconomic status. Within fifteen days and 30 days postpartum, two quantitative 24-h recalls were obtained from each woman on different days [10, 11] to evaluate the dietary intakes and menus. In addition, the diets of a sub-sample of 30 women who were still exclusively breastfeeding were analyzed at 90 days post-partum to obtain a total of four 24-h recalls for each woman. The 24-recalls for the sub-sample of women were used to calculate the coefficient of variation of intakes within women.
Any vitamin or mineral supplement taken was recorded. Sodium intake was calculated from food composition and added salt was not recorded. Assessment of the amounts consumed was aided by the use of plastic food models, calibrated cups, glasses, plates and spoons, as well as cardboard models of serving sizes. Dietary data were coded and analyzed by the same interviewer using the Food Composition Database compiled by Ortega et al. [12]. The intake distribution of each nutrient was adjusted according to NRC [13] to remove the effect of day-to-day variation. This approach used logarithmically transformed data to assure a normal distribution; an algorithm for the adjusted intake of each nutrient which used the inter- and intra-standard deviations of the data was applied. By computing the exponential of the values, the distribution was converted back to the original units and could then be used as an estimate of the distribution of usual intakes.
Energy requirements for adolescent and adult groups were obtained using the equations recommended by the Food and Nutrition Board [6], using current mean age, weight, height and the physical activity coefficient (PA), which is based on the physical activity level (PAL) of the women (as an example, PA = 1 if PAL 
1 or <1.4; PA = 1.11 if PAL 1.4 or <1.6). Dietary patterns and menus were obtained on the basis of consumption frequency and the usual combination of foods in the studied groups diets [14].
Weight, Height and Physical Activity Level
Maternal body weight was measured using an electronic balance (AND FG-150k, 150 ± 0.05 kg capacity) and height was measured with a field device calibrated with a stadiometer. Body mass index (BMI) was calculated as weight/height2. Physical activity patterns were assessed using a 7-day physical activity questionnaire validated with Doubly Labeled Water [15].
Statistical Analyses
The NCSS statistical package [16] was used for data analysis. Student's Independent t-test was used to test for mean differences between regional and aged separated groups. Significant probability level was set at p 
0.05.
|
RESULTS |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSCONCLUSIONSACKNOWLEDGMENTSREFERENCES |
|---|
Energy, Fiber and Selected Nutrient Intake
Table 1 shows energy and selected nutrient intakes of the women and the prevalence of inadequacy according to the DRIs (Dietary Reference Intakes) when they are known. The energy requirements are based on different equations according to age; therefore in Table 1 these requirements are different for adolescent and adult women. The mean intake of fat was 95 ± 70 grams, lactating women consumed 15% of energy from protein, 48% of energy from carbohydrates, 37% and 15% of energy from total and saturated fat respectively. Cholesterol and total dietary fiber mean intakes were 563 ± 749 mg and 25 ± 18 grams per day respectively.
|
Energy and nutrient intake levels of both regional groups (Northwest and Mexico City) are shown in Table 2. Energy intakes were significantly higher in the Northwest when compared to Mexico City, as were macronutrients, mono- and poly-unsaturated fat, dietary fiber, sodium, iron and folate. From Table 3, weight and height were greater (p < 0.01) in Northwestern women compared to Mexico City women.
|
|
Dietary Patterns
The typical menu for lactating women in Northwest and Mexico City showed more than one pattern for each meal, although only the most frequently consumed food items in each pattern are presented (Table 4). Foods consumed by Northwestern women were wheat and corn tortillas, beans, whole milk, eggs for breakfast, fried meat and French fries for lunch. They consumed some vegetables, such as lettuce and tomato, cola type beverages for lunch and almost no fruits but oranges at mid-afternoon. The dietary pattern of women from Mexico City was different from Northwest Mexico. Milk, coffee, biscuit and yogurt are part of their habitual diet as well as noodles soup and boiled chicken. They consumed corn but not wheat tortilla, and beans were not common in their diet. They also consumed fruits such as apples and bananas, as well as vegetables like carrots, and chayote (white pear), which were included in the chicken soup. Fish consumption was present in neither Northwest nor Mexico City regions.
|
|
DISCUSSION |
|---|
Women from Northwest Mexico consumed energy dense foods (fried meat and beans, French fries, potato chips) which are common in the Northwestern diets [8], with a poor consumption of fruits or vegetables, but oranges, tomatoes and lettuce. Women consuming excessive fatty and sweet foods may affect their nutritional status being overweight or obese, in addition to weight gain during pregnancy. A consequence of excessive weight could be an increased risk factor for cardiovascular or diabetes diseases, which are respectively the first and fourth causes of death in Mexico.
Although the mean protein intake was higher than the recommended, 30% of the women had protein intakes lower than the recommendation. Meat ingestion and the frequency of beans and tortillas consumption could be a reason of higher consumption of proteins in some of the women in the present study.
The percentage of energy obtained from macronutrient sources was in agreement with the Acceptable Macronutrient Distribution Range (AMDR-range of intakes that the U.S. Food and Nutrition Board considers healthful) for protein and carbohydrates and was higher than the AMDR of 20–35% for fat. In the Northwest region, most of the fat was provided by animal products like beef, dairy products, fried potatoes and oils or solid fats used in the preparation of frying beans or wheat tortillas. The consumption of sea products in the diet of both groups of lactating women was quite small, and a low contribution of omega-3 fatty acids could be expected. Women in this study showed cholesterol intakes higher than the recommended and the reported in Mexican lactating women [8,18]. Intrauterine growth is influenced by maternal factors; a poor maternal diet may promote further obesity, insulin resistance and type 2 diabetes of the infant [19]. In lactating women, weight gain during pregnancy could be another reason to recommend the appropriate caloric intake and proportions of macronutrients in order to achieve the original weight in the post-partum period or later.
Dietary fiber intakes were significantly higher in the Northwestern than in the Mexico City group, primarily due to the intake of pinto beans, corn tortillas and wheat flour tortillas. Cereals and legumes are known to have a high proportion of non-cellulose polysaccharides, which are considered beneficial in preventing cardiovascular disease [20]. However, according to Wyatt et al. [21] 72% of the total dietary fiber in the Northwestern diet is insoluble.
Women from de Northwest region consumed a limited variety of fruits and vegetables. Although fruit consumption was present in the diet of women from Mexico City, it was not enough to contribute to a higher intake of some micronutrients; the relatively low energy intakes in these women led to low intakes of several other nutrients. The 2000 Dietary Guidelines Advisory Committee recommends vegetable and fruit consumption of 5 to 9 servings per day. Northwestern women consumed 4 servings per day on average, while women from the Mexico City area consumed 2.5 servings (not considering fruit drinks or vegetables in meat dishes). However, there was a great variety of consumption of fruits and vegetables among Mexico City women.
Although zinc intakes of women in our study were lower than the recommendation, mean values were comparable to those reported by other authors in different populations [22,23]. In addition to total amount of zinc, it is important to consider bioavailability; in Mexican diets the availability of zinc (measured as solubility) was poor [24]. A large percentage of women consumed whole milk and yogurt in their diets, which are adequate sources of calcium; however, calcium intakes must be taken with caution, because bone metabolism during and after lactation is poorly understood. In a study with rural Mexican women [25], calcium balance was negative at 1, 3 and 6 months post-partum. Taking into account calcium availability, it is of concern that some of the women in our study had low calcium intakes. They also showed high sodium intakes, which can lead to increased calcium excretion [26].
Meat ingestion and the frequency of beans consumption could be a reason of lower prevalence of anemia in the Northwest population [27] in comparison to the prevalence of anemia among women from Mexico City [28]. Iron in the diet of women from the Mexico City region comes mainly from vegetable sources, and consequently bioavailability has shown to be low [24]. The use of dietary supplements was not common in this study, only 26% of the women in Mexico City ingested any of them: iron (10.5%), calcium (5.5%) or multivitamins (10.5%). In Northwest Mexico, 31% of the women were taking supplements at this time of lactation.
Besides its manifestation as the classical clinical deficiency megaloblastic anemia, sub clinical folate deficiency has been associated with increased risk for cardiovascular diseases and various types of cancer [29]. Therefore, there are some reasons to believe that 77% prevalence of inadequacy in folate intakes found in this study could imply future health risks for both the mother and infant.
It is essential for lactating women to have adequate stores of vitamin A as well as vitamins C and E, as evidence suggests that breast milk is affected by current intakes [2,30]. Although 52% of women showed intakes of vitamin A below the recommendation, it was not concluded that this is insufficient because only two 24-h records were collected and vitamin A intake varies markedly from day to day.
Mexican society is marked by cultural beliefs about restriction of foods during lactation, especially in the central and southern regions of the country. Some of the restricted foods are fish, beans and condiments. The low consumption of fish in all the subjects and the restricted ingestion of beans in Mexico City may be due in part to these beliefs. The overall physical activity for the women in this study was low (physical activity level = 1.48); this low active behavior was expected since the study was done on the first 40 days post-partum and physical activity is restricted in this period.
In interpreting our overall findings, we acknowledge that one of the limitations in this study was the small sample size, due to the difficulties finding women who were exclusively breastfeeding. There may be some limitations on the use of two 24 recalls to assess nutrient intake. For micronutrients intake, especially vitamins A and C, seasonality and the number of foods that contain the nutrients in the diets can affect inter- and intra- subject variations. Sampling subjects from more than one hospital in each region may have been more representative of the populations being studied. Selection of the hospitals was based on their focus in low socioeconomic pregnant women and on the fact that they concentrate most of the adolescent pregnant women in each region.
|
CONCLUSIONS |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSCONCLUSIONSACKNOWLEDGMENTSREFERENCES |
|---|
Nutritional orientation of Mexican lactating women should emphasize on adequate nutrient intakes in order to minimize the risk of adverse effects on maternal or infant nutritional status and health. Education about the importance of the maternal diet during lactation should be directed toward increasing consumption of foods rich in micronutrients. These foods must include a variety of grains, vegetables and fruits, and less consumption of sweets and some kinds of fats. In general, nutritional goals would improve variety and lower the saturated fat consumption without compromising energy intake.
Food and nutrition educators can pursue three strategies: (1) to provide lactating women with a more conceptual understanding of the types of foods they are eating, and the maternal and infant nutritional consequences of deficiency and excess; (2) to provide some "easy to understand" material to help the women planning their diets and (3) to apply these actions inside the Baby Friendly Hospital Initiative, to obtain better outcomes from the Mexican lactating women.
|
ACKNOWLEDGMENTS |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSCONCLUSIONSACKNOWLEDGMENTSREFERENCES |
|---|
Received July 25, 2004. Accepted July 18, 2006.
|
REFERENCES |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSCONCLUSIONSACKNOWLEDGMENTSREFERENCES |
|---|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
