Biomedical subjects

A M Siega-Riz

Publications and source records attributed to A M Siega-Riz.

At least 19 recordsLinked to original sources

PubMed2003

Maternal stress and preterm birth.

This study examined a comprehensive array of psychosocial factors, including life events, social support, depression, pregnancy-related anxiety, perceived discrimination, and neighborhood safety in relation to preterm birth (<37 weeks) in a prospective cohort study of 1,962 pregnant women in central North Carolina between 1996 and 2000, in which 12% delivered preterm. There was an increased risk of preterm birth among women with high counts of pregnancy-related anxiety (risk ratio (RR) = 2.1, 95% confidence interval (CI): 1.5, 3.0), with life events to which the respondent assigned a negative impact weight (RR = 1.8, 95% CI: 1.2, 2.7), and with a perception of racial discrimination (RR = 1.4, 95% CI: 1.0, 2.0). Different levels of social support or depression were not associated with preterm birth. Preterm birth initiated by labor or ruptured membranes was associated with pregnancy-related anxiety among women assigning a high level of negative impact weights (RR = 3.0, 95% CI: 1.7, 5.3). The association between high levels of pregnancy-related anxiety and preterm birth was reduced when restricted to women without medical comorbidities, but the association was not eliminated. The prospective collection of multiple psychosocial measures on a large population of women indicates that a subset of these factors is associated with preterm birth.

Adolescent↗

PubMed2001

Frequency of eating during pregnancy and its effect on preterm delivery.

Frequency of eating or meal patterns during pregnancy may be a component of maternal nutrition relevant to pregnancy outcome. To identify meal patterns of pregnant women and investigate the relation between these meal patterns and preterm delivery, the authors performed an analysis using data from the Pregnancy, Infection, and Nutrition Study (n = 2,065). Women recruited from August 1995 to December 1998 were categorized by meal patterns on the basis of their reported number of meals (breakfast, lunch, and dinner) and snacks consumed per day during the second trimester. An optimal pattern was defined according to the Institute of Medicine recommendation of three meals and two or more snacks per day. In this population, 72 percent of the women met this recommendation, and 235 delivered preterm. Women who consumed meals/snacks less frequently were slightly heavier prior to pregnancy, were older, and had a lower total energy intake. In addition, these women had a higher risk of delivering preterm (adjusted odds ratio = 1.30, 95 percent confidence interval: 0.96, 1.76). There was no meaningful difference in the risk by early versus late preterm delivery, but those who delivered after premature rupture of the membranes (adjusted odds ratio = 1.87, 95 percent confidence interval: 1.02, 3.43) had a higher risk than those who delivered after preterm labor (adjusted odds ratio = 1.11, 95 percent confidence interval: 0.64, 1.89). This study supports previous animal model work of an association between decreased frequency of eating and preterm delivery.

Adolescent↗

PubMed2001

Where's the fat? Trends in U.S. diets 1965-1996.

BACKGROUND: Controlling fat intake has been an ongoing health concern since the late 1950s. This study examines 30-year trends in food sources of fat intake. It focuses on both total fat and specific fatty acid classes to ascertain if there are trend differences by age, sex, or race/ethnicity. METHODS: Nationally representative cross-sectional U.S. Department of Agriculture surveys from 1965, 1977-1978, 1989-1991, and 1994-1996 form the basis of this analysis, which compares 45,357 adults aged 18 years and older. Food files linked over time are used to create comparable food groups and nutrient values. RESULTS: The proportion of fat in the diet from grain-based mixed dishes, higher-fat snack foods, and higher fat potatoes has increased to partially offset reductions in fat from dairy, red meat, and added fat categories. Food sources of fat differ by race/ethnicity and age. The percentage of fat from fast foods and ethnic foods increased over time from 1 to 11% of total fat. The ratio of visible to invisible fat declined considerably. CONCLUSION: While animal product-based sources of fat continue to require emphasis, the shift toward fast foods, fried foods, and grain-based mixed dish and edible oil sources requires more focus.

Adolescent↗

PubMed2001

Significant increase in young adults' snacking between 1977-1978 and 1994-1996 represents a cause for concern!

BACKGROUND: Studies on children and adolescents suggest a large increase in the role of snacking; however, little is know about changes in the snacking behavior of young adults. METHODS: USDA's nationally representative surveys from 1977-1978 to 1994-1996 are used to study snacking trends among 8,493 persons 19-29 years old. RESULTS: Snacking prevalence increased from 77 to 84% between 1977-1978 and 1994-1996. The nutritional contribution of snacks to total daily energy intake went from 20 to 23%, primarily because energy consumed per snacking occasion increased by 26% and the number of snacks per day increased 14%. The mean daily caloric density (calorie per gram of food) of snacks increased from 1.05 to 1.32 calories. The energy contribution of high-fat desserts to the total calories from snacking decreased (22 to 14%), however, this food group remained the most important source of energy. The energy contribution of high-fat salty snacks doubled. Sweetened and alcoholic beverages remained important energy contributors. CONCLUSION: This large increase in total energy and energy density of snacks among young adults in the United States may be contributing to our obesity epidemic.

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PubMed2001

Prolonged periods without food intake during pregnancy increase risk for elevated maternal corticotropin-releasing hormone concentrations.

OBJECTIVE: Fasting during pregnancy stimulates preterm delivery in animals and increases women's risk for preterm delivery. Fasting stimulates hypothalamic corticotropin-releasing hormone production in animals. Elevated maternal corticotropin-releasing hormone concentrations are associated with preterm birth. We hypothesized that prolonged periods without food during pregnancy increase maternal corticotropin-releasing hormone concentrations, which lead to preterm delivery. STUDY DESIGN: In the Behavior in Pregnancy Study, we examined prolonged periods without eating during pregnancy and corticotropin-releasing hormone concentrations and gestational age at delivery with multivariate logistic regression analysis (n = 237). RESULTS: Prolonged periods without food lasting 13 hours or longer were associated with elevated maternal corticotropin-releasing hormone concentrations compared with prolonged periods without food lasting less than 13 hours at two time points during pregnancy, controlling for pregravid body mass index, energy intake, income, race, smoking, and maternal age (18-20 weeks: adjusted odds ratio, 2.5; 95% CI, 0.9-7.1; 28-30 weeks: adjusted odds ratio, 1.7; 95% CI, 0.7-4.2). There was an inverse, linear relationship between maternal corticotropin-releasing hormone concentrations and gestational age at delivery. CONCLUSIONS: Prolonged periods without food intake during pregnancy are associated with elevated maternal corticotropin-releasing hormone concentrations and with preterm delivery.

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PubMed2001

High prevalence of postpartum anemia among low-income women in the United States.

OBJECTIVE: To determine the prevalence of anemia from 4 to 26 weeks post partum and to examine prenatal predictors of postpartum anemia. STUDY DESIGN: Retrospective cohort analysis of 59,428 participants in the Special Supplemental Nutrition Program for Women, Infants, and Children in 12 US states. RESULTS: The prevalence of postpartum anemia was 27%. Anemia rates were higher among minority women, reaching 48% among non-Hispanic black women. Of 9129 women who had normal hemoglobin in the third trimester, 21% had postpartum anemia. Prenatal anemia was the strongest predictor of postpartum anemia (adjusted odds ratio, 2.7; 95% confidence interval, 2.5-2.8). Maternal obesity, multiple birth, and not breast-feeding also predicted postpartum anemia. CONCLUSION: The high prevalence of post partum anemia among low-income women highlights the importance of anemia screening at 4 to 6 weeks post partum. These data suggest that screening should not be limited, as it is at present, to women considered at high risk.

Adolescent↗

PubMed2001

The increasing prevalence of snacking among US children from 1977 to 1996.

OBJECTIVES: To determine snacking trends and changes in nutrient contribution of snacking over time. STUDY DESIGN: Nationally representative data from the 1977-78 Nationwide Food Consumption Survey (NFCS77), 1989-91 Continuing Survey of Food Intake by Individuals (CSFII89), and 1994-96 (CSFII96) were used. The sample consisted of 21,236 individuals aged 2 to 18 years. METHODS: For each survey year, mean numbers of snacks consumed, mean grams consumed per snack, and mean energy intake from snacks were computed, as was contribution of snacking to total energy intake and fat intake. Snacking was self-defined, and a snacking occasion consisted of all snack foods consumed during a 15-minute period. Differences in means between age groups and across survey years were compared. RESULTS: The prevalence of snacking increased in all age groups. The average size of snacks and energy per snack remained relatively constant; however, the number of snacking occasions increased significantly, therefore increasing the average daily energy from snacks. Compared with non-snack eating occasions, the nutrient contribution of snacks decreased in calcium density and increased in energy density and proportion of energy from fat. CONCLUSION: Snacking is extremely prevalent in our society. Healthy snack food choices should be emphasized over high-energy density convenience snacks for children.

Adolescent↗

PubMed2001

Data correction.

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Adolescent↗

PubMed2001

Dietary trends among low socioeconomic status women of childbearing age in the United States from 1977 to 1996: a comparison among ethnic groups.

OBJECTIVE: To identify dietary trends among low socioeconomic status women of childbearing age from three ethnic groups from 1977 to 1996. METHODS: The sample consisted of 19- to 44-year-old women at 185% of poverty with 12 years of education or less (n = 4682) from three US Department of Agriculture surveys. The Revised Diet Quality Index (DQI-R) and level of folate were the main outcomes measured. Changes in food consumption for several food groups were also examined. RESULTS: Diet quality significantly improved between 1977 and 1996 for Hispanics and non-Hispanic whites. All groups had significant decreases in saturated fat intake by 1996, but only Hispanic and non-Hispanic white women significantly decreased their total fat and cholesterol intakes. Fruit and vegetable intakes remained stable. Mean intakes of calcium, iron, and folate were below recommendations at every time point for all ethnic groups. All three groups decreased their intakes of butter, margarine, egg items, bacon, high-fat red meats, and low-fiber/high-fat breads and increased their intakes of high-fiber cereals, all of which are positive. These trends were balanced, however, by decreases in medium-fiber vegetables, soy, and legumes and increases in high-fat/high-fiber breads, high-fat desserts, high-fat salty snacks, and high-fat grain-based mixed dishes. CONCLUSIONS: This study highlights problem dietary habits that public health professionals need to address in order to reduce the prevalence of diet-related chronic diseases.

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PubMed2000

Differences in food patterns at breakfast by sociodemographic characteristics among a nationally representative sample of adults in the United States.

BACKGROUND: Eating breakfast is considered an important determinant of a healthy lifestyle. This study explores the different food patterns of breakfast for adults aged 18-65 in the United States. METHODS: Data are from the 1994-1996 Continuing Survey of Food Intake by Individuals, n = 15,641. Dietary assessment method used was the 24-h recall. Nutrient differences among the breakfast food patterns as well as the sociodemographic characteristics of individuals following each eating pattern are examined. RESULTS: The primary food patterns were based on consumption of eggs (15.3% of adults), ready-to-eat cereals (17.4%), bread (21.7%), cooked cereal (4.4%), fruit and fruit juice (5.5%), and coffee, soft drinks, and high-fat desserts (15.1%). Seventeen and three-tenths percent of the adults skipped breakfast. These food patterns provide remarkably different nutrient profiles adjusting for energy intake. The egg pattern is highest in total fat, lowest in fiber density, and low in iron and calcium density. In contrast, the ready-to-eat cereal pattern is high in fiber, highest in calcium density, and very low in fat. Breakfast food patterns differ markedly by various sociodemographic factors such as gender, ethnicity, and educational level. CONCLUSION: Different segments of our population consume different types of foods at breakfast, contributing to differences in their nutrient intakes.

Adolescent↗

PubMed2000

US adolescent food intake trends from 1965 to 1996.

AIM: To examine adolescent food consumption trends in the United States with important chronic disease implications. METHODS: Analysis of dietary intake data from four nationally representative United States Department of Agriculture surveys of individuals 11-18 years of age (n = 12 498). RESULTS: From 1965 to 1996, a considerable shift in the adolescent diet occurred. Total energy intake decreased as did the proportion of energy from total fat (39% to 32%) and saturated fat (15% to 12%). Concurrent increases occurred in the consumption of higher fat potatoes and mixed dishes (pizza, macaroni cheese). Lower fat milks replaced higher fat milks but total milk consumption decreased by 36%. This decrease was accompanied by an increase in consumption of soft drinks and non-citrus juices. An increase in high fat potato consumption led to an increase in vegetable intake but the number of servings for fruits and vegetables is still below the recommended five per day. Iron, folate, and calcium intakes continue to be below recommendations for girls. CONCLUSIONS: These trends, far greater than for US adults, may compromise health of the future US population.

Adolescent↗

PubMed2000

US adolescent food intake trends from 1965 to 1996.

OBJECTIVE: To examine adolescent food consumption trends in the United States with important chronic disease implications. METHODS: Analysis of dietary intake data from 4 nationally representative US Department of Agriculture surveys of persons aged 11 to 18 years (n = 12,498). RESULTS: From 1965 to 1996, a considerable shift occurred in the adolescent diet. Total energy intake decreased, as did the proportion of energy from total fat (39%-32%) and saturated fat (15%-12%). Concurrent increases occurred in the consumption of higher-fat potatoes and mixed dishes (pizza and macaroni and cheese). Lower-fat milks replaced higher-fat milks, but total milk consumption decreased by 36%. This decrease was accompanied by an increase in the consumption of soft drinks and noncitrus juices. An increase in high-fat potato consumption led to an increase in vegetable intake, but the number of servings for fruits and vegetables is still lower than the recommended 5 per day. Iron, folic acid, and calcium intakes continue to be below those recommended for girls. CONCLUSIONS: These trends, far greater than for US adults, may compromise the health of the future US population.

Adolescent↗

PubMed1999

The Diet Quality Index revised: a measurement instrument for populations.

OBJECTIVE: To evaluate a revision of the Diet Quality Index called the Diet Quality Index Revised (DQI-R). DESIGN: The original Diet Quality Index was revised to reflect current dietary guidance, to incorporate improved methods of estimating food servings, and to develop and incorporate measures of dietary variety and moderation. The scoring of the original scale was reversed in direction and expanded to a 100-point scale to improve interpretability. METHODS/SUBJECTS: Data from the 1994 Continuing Survey of Food Intakes by Individuals were used. A sample of 3,202 adults aged 18 and older contributed 2 days of dietary intake data based on 24-hour recalls for the development and revision of various components of the DQI-R. STATISTICAL ANALYSES: Pearson correlation analyses, ordinary least squares regression analyses, and a nonparametric test to determine trends across ordered groups were used. RESULTS: The mean DQI-R score for the 1994 sample was 63.4 of a possible 100-point score. Sample respondents were more likely to have met dietary guidance in the areas of dietary cholesterol (66.9% met goal) and iron intakes (59.6% met goal) relative to the Recommended Dietary Allowances but less likely to have met goals related to fruit servings (19.6% met goal), grain servings (23.1% met goal), and calcium intakes (16.6% met goal) relative to the Recommended Dietary Allowance. There is a statistically significant quantitative and qualitative improvement in all components of the DQI-R as one moves from the lowest grouping of scores to the highest. For example, persons with DQI-R scores less than 40 consumed 43.9% of energy from fat, 72% of the Adequate Intake for calcium, and 6.7% of the recommended servings of fruit per day. In contrast, those with DQI-R scores greater than 80 consumed 24.2% of energy from fat, 101% of the Adequate Intake for calcium, and 137% of the recommended servings of fruit per day. APPLICATIONS: The DQI-R reflects the dietary guidance principles of macronutrient distribution, moderation, variety, and proportionality. Although the index was designed to monitor dietary changes in populations rather than individuals, each index component reflects an aspect of national dietary guidance. Calculation of DQI-R scores for an individual should provide an estimate of diet quality relative to national guidelines, and differences in scores over time should suggest improvement or decline in overall diet quality.

Adolescent↗

PubMed1998

Three squares or mostly snacks--what do teens really eat? A sociodemographic study of meal patterns.

PURPOSE: To categorize U.S. adolescents' meal patterns and related differences in dietary quality. METHODS: Using data from the Continuing Survey of Food Intake by Individuals, 1989-1991, meal patterns from 3 days of adolescents' (ages 11-18 years) intake (n = 1310) were examined. Consistency of meal pattern intake and associated nutrient quality was determined. Logistic regression was used to examine the effects of several sociodemographic characteristics on meal pattern consistency. RESULTS: A higher percentage of adolescents consumed a meal pattern that included 3 meals/day than any other meal pattern: 57.4-58.7% on any given day. Forty-one percent of adolescents fell into the consistent (at least two meals on all 3 days), and only 3.5% fell into the inconsistent meal (one meal, with or without snacks, or snacks only, on all 3 days) pattern category. Logistic regression results indicated that being black [adjusted odds ratio (AOR) = 4.19, 95% confidence interval (CI) (1.90, 9.27)], older (15-18) [AOR = 1.41, 95% CI (1.19, 1.67)], and from a single-parent household [AOR = 2.60, 95% CI (1.23, 5.52)] were predictive of an inconsistent meal pattern. School lunch has a positive impact on intake, increasing a consistent meal pattern from 36.0% to 44.9%. CONCLUSIONS: Adolescents who consume at least two meals (with or without snacks) on a consistent basis have an adequate intake of calories and a more nutrient-dense diet with respect to calcium, iron, vitamin E, and fiber than those with other meal patterns. From the perspective of following a diet to prevent chronic diseases in adulthood, adolescents regardless of meal pattern, consume a diet that is too high in fat, sodium, and protein, and too low in fiber.

Adolescent↗

PubMed1998

Maternal hematologic changes during pregnancy and the effect of iron status on preterm delivery in a West Los Angeles population.

This study was conducted to document the prevalence of anemia and high hematocrit during pregnancy and examine their effect on delivering preterm in a predominantly Hispanic population. The sample consisted of women receiving prenatal care from the public health clinics in the West Los Angeles from 1983 to 1986 (n = 7589). Multivariate logistic regression was used to isolate the role of anemia and high hematocrit from other factors that may influence birth outcome. The prevalence of anemia was approximately 9% at the initiation of prenatal care and at 28-32 weeks' gestation. Only anemia at 28-32 weeks was significantly associated with a preterm birth, even after adjusting for several confounders [Adjusted Odds Ratio (AOR) 1.83 95% Cl = 1.21, 2.77]. A high hematocrit that occurred in 9.6% of the population at 28-32 weeks was inversely associated with a preterm birth (AOR 0.78, 95% Cl = 0.44, 1.39). There was little differentiation of these risk factors when analyzing the etiological pathways of a preterm birth. These results indicate for the first time in a predominantly Hispanic population that despite routine iron supplementation, anemia still occurs in pregnant women and it can predict a preterm delivery.

Adult↗

PubMed1998

Trends in breakfast consumption for children in the United States from 1965-1991.

We examined breakfast consumption patterns and trends between 1965 and 1991 for children (1-10 y old) and adolescents (11-18 y old) in the United States. The analysis was undertaken by pooling nationally representative samples obtained from the Nationwide Food Consumption Surveys of 1965 and 1977-1978 and the 1989-1991 Continuing Survey of Food Intakes by Individuals. Breakfast consumption, defined as the consumption of food, beverage, or both between 0500 and 1000, was the focus of the trends analysis. Descriptive results indicated a decline in breakfast consumption between 1965 and 1991, particularly for older adolescents aged 15-18 y; the rates for boys and girls declined from 89.7% and 84.4%, respectively, in 1965 to 74.9% and 64.7%, respectively, in 1991. Multivariate results indicated that breakfast consumption declined predominantly because of behavioral changes and not the population's changing sociodemographic patterns. The nutritional quality of foods consumed at breakfast has improved since 1965, with significant shifts toward consumption of lower-fat milk and smaller changes in other food groups. The improvement over time in the quality of food consumed at breakfast, however, is offset by the large percentage of persons aged > or = 11 y who do not presently consume breakfast. Given the association of obesity with less frequent breakfast consumption and the rise in obesity among persons of this age group, a renewed emphasis on the importance of breakfast is warranted.

Adolescent↗

PubMed1997

Predictors of poor maternal weight gain from baseline anthropometric, psychosocial, and demographic information in a Hispanic population.

OBJECTIVE: To identify which baseline factors best predict poor maternal weight gain among Hispanics. SAMPLE: Pregnancy and outcome data collected prospectively from 4,791 Hispanic women attending public prenatal clinics in West Los Angeles, Calif, from 1983 through 1986. METHODS: Prepregnancy weight was categorized into weight status groups using body mass index (BMI). Poor total weight gain (based on a mean gestational age at last measurement, which was at 35 weeks) was defined as less than 21 lb for women with BMI less than 26 and less than 10 lb for women with BMI of 26 or greater. Analyses used Student's t test, chi 2, and multivariate regression techniques (linear and logistic). RESULTS: Poor total weight gain was identified in 29% of the women. For women who were underweight or normal weight before pregnancy, the only factor associated with increasing the risk of poor total weight gain was short stature (adjusted odds ratio [AOR] = 1.5, 95% confidence interval [CI] = 1.24, 1.84). The following factors decreased the risk: being US born (AOR = 0.61, 95% CI = 0.37, 1.00); being primiparous and under 29 years old (for < 20 years AOR = 0.69, 95% CI = 0.51, 0.92 and for 20 to 29 years AOR = 0.63, 95% CI = 0.49, 0.81); planning the pregnancy (AOR = 0.82, 95% CI = 0.67, 1.00); and having a close relative die during the pregnancy (AOR = 0.65, 95% CI = 0.44, 0.95). For obese and overweight women, physical abuse by the baby's father increased the risk (AOR = 3.19, 95% CI = 1.27, 8.01) of poor total weight gain, whereas receiving financial support from the baby's father decreased the risk (AOR = 0.59, 95% CI = 0.37, 0.95). APPLICATIONS/CONCLUSIONS: These baseline factors could aid in targeting nutrition and other social services earlier to pregnant Hispanic women. By strategically targeting pregnant women in greatest need of services, improvements in birth outcomes may be enhanced.

Adult↗

PubMed1996

A comparison of dietary trends among racial and socioeconomic groups in the United States.

BACKGROUND: There may be dietary differences among racial and socioeconomic groups in the United States. METHODS: Using data from a representative sample of adults, we compared dietary trends among blacks and whites of varying socioeconomic status. We developed comparable measures of diet and of the consumption of macronutrients and food groups for 6061 participants in the 1965 Nationwide Food Consumption Surveys, 16,425 in the 1977-1978 Nationwide Food Consumption Surveys, and 9920 in the 1989-1991 Continuing Survey of Food Intake by Individuals (all conducted by the U.S. Department of Agriculture). The primary outcome was the score (range, 0 to 16) on the Diet Quality Index, a composite of eight food-and-nutrient-based recommendations from the National Academy of Sciences. A score of 4 or less was considered to indicate a relatively more healthful diet, and a value of 10 or more a relatively less healthful diet. RESULTS: Overall dietary quality improved in all groups, from a mean Diet Quality Index score of 7.4 in 1965 to 6.4 in 1989-1991. In 1965, blacks of low socioeconomic status and, to a lesser extent, whites of low socioeconomic status had better diets than whites of high socioeconomic status. By the 1989-1991 survey, the differences among racial and socioeconomic groups had narrowed. In 1965, 9.3 percent of whites of low socioeconomic status, 16.4 percent of blacks of low socioeconomic status, and 4.7 percent of whites of high socioeconomic status had mean scores of 4 or less. In the 1989-1991 survey the respective percentages were 19.9, 23.5, and 20.0. Fat consumption decreased in all groups. The consumption of fruits and vegetables varied little over time, except for an increase among blacks of medium and high socioeconomic status. The consumption of grains and legumes increased over time among whites of medium and high socioeconomic status and declined among blacks of low socioeconomic status. CONCLUSIONS: In 1965, there were large differences among groups in dietary quality, with whites of high socioeconomic status eating the least healthful diet, as measured by the index, and blacks of low socioeconomic status the most healthful. By the 1989-1991 survey, the diets of all groups had improved and were relatively similar.

Adult↗