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

Response to Camacho

We appreciate Dr. Camacho’s interest in our article (Desrosiers, Siega-Riz, Mosley, Meyer, & National Birth Defects Prevention Study, 2018), and welcome the opportunity to respond. As Dr. Camacho emphasizes, the association between folic acid and neural tube defects (NTDs) is well established (Viswanathan et al., 2017). What is less certain are factors potentially related to folate insufficiency among women of reproductive age, and even more so, among women who meet the U.S. Preventative Health Task Force’s recommendation of 0.4–0.8 mg/day of supplemental folic acid (Tinker, Hamner, Qi, & Crider, 2015; US Preventive Services Task Force, 2017). Understanding the reasons for folate insufficiency could help prevent some cases of birth defects in the future and is thus a worthy research pursuit. One theory expressed in the literature is whether avoidance of carbohydrate-rich foods such as enriched grains (fortified with folic acid) and beans (high in natural folate) could lead to meaningful reductions in folate status, which could in turn lead to an increased risk for some women of having an NTD-affected pregnancy (Mills, 2017; Quinlivan & Gregory, 2007)

Response to Harcombe

The crux of Dr. Harcombe’s critique is her assertion that our study design was inappropriate for our research objective, which was to investigate whether maternal carbohydrate restriction before conception was associated with neural tube defects (NTDs) in the National Birth Defects Prevention Study (NBDPS), a population-based case-control study of birth defects (Desrosiers, Siega-Riz, Mosley, Meyer, & The National Birth Defects Prevention Study, 2018). In her Letter, Dr. Harcombe claims that our study is fundamentally flawed because “cases should have been women who restrict carbohydrates and the controls should have been women who don’t and the outcome measure should have been NTD-affected pregnancies.” Despite her confusing (mis)use of the terms case and control, what Dr. Harcombe appears to be describing is a cohort study

Gestational weight gain and predicted changes in offspring anthropometrics between early infancy and 3 years

Objective: To determine how gestational weight gain (GWG), categorized using the 2009 Institute of Medicine recommendations, relates to changes in offspring weight-for-age (WAZ), length-for-age (LAZ) and weight-for-length z-scores (WLZ) between early infancy and 3 years. Methods: Women with singleton infants were recruited from the third cohort of the Pregnancy, Infection, and Nutrition Study (2001-2005). Term infants with at least one weight or length measurement during the study period were included (n = 476). Multivariable linear mixed effects regression models estimated longitudinal changes in WAZ, LAZ and WLZ associated with GWG. Results: In early infancy, compared with infants of women with adequate weight gain, those of women with excessive weight gains had higher WAZ, LAZ and WLZ. Excessive GWG ≥ 200% of the recommended amount was associated with faster rates of change in WAZ and LAZ and noticeably higher predicted mean WAZ and WLZ that persisted across the study period. Conclusions: GWG is associated with significant differences in offspring anthropometrics in early infancy that persisted to 3 years of age. More longitudinal studies that utilize maternal and paediatric body composition measures are necessary to understand the nature of this association

Maternal lipid levels during pregnancy and child weight status at 3 years of age

Background: The intrauterine environment is critical in the development of child obesity. Objective: To investigate the association between maternal lipid levels during pregnancy and child weight status. Methods: Maternal lipid levels (total cholesterol, high-density and low-density lipoprotein cholesterol, triglycerides) collected from fasting blood samples collected at less than 20 and 24–29 weeks' gestation and child weight status at age 3 were examined prospectively among 183 mother-child dyads enrolled in the Pregnancy, Infection, and Nutrition. Measured height and weight at 3 years were used to calculate age- and sex-specific body mass index z-scores. Child risk of overweight/obesity was defined as body mass index greater than or equal to 85th percentile for age and sex. Regression models estimated the association between maternal lipid levels and child body mass index z-score and risk of being affected by overweight/obesity, respectively. Results: Higher triglyceride levels at less than 20 and 24–29 weeks of pregnancy were associated with higher body mass index z-scores (β = 0.23; 95% CI: 0.07-0.38 and β = 0.15; 95% CI: 0.01-0.29; respectively) after adjusting for confounders. There was no evidence of an association between total or low-density lipoprotein cholesterol and child weight status at age 3. Conclusions: Early childhood body mass index may be influenced by maternal triglyceride levels during pregnancy

Dietary trends inteh United States [1] (multiple letters)

The authors reply: To the Editor: Nusbaum and Eshleman suggest that dietary trends may reflect respondents’ adherence to the dietary guidelines of the time. From 1916 to 1976, nutritional recommendations relative to the basic food groups were fairly stable. The basic five food groups of 1916 were reduced to the basic four (two daily servings of milk and of meat, poultry, or eggs and four daily servings of fruits and vegetables and of breads and grains) in the 1960s. Not until the introduction of the U.S. Dietary Goals in 1977 did dietary guidelines explicitly recommend nutrient limitations for fats, sugars, and cholesterol. Neither our group nor others have attempted to quantify the dietary guidelines of the 1960s or to ascertain who followed the guidelines most closely

Preconceptional cardiovascular health and pregnancy outcomes in women with systemic lupus erythematosus

Objective. To estimate the effects of preconceptional cardiovascular (CV) health, measured by American Heart Association (AHA) guidelines, on pregnancy outcomes in women with systemic lupus erythematosus (SLE). Methods. The study included patients in the Hopkins Lupus Pregnancy Cohort. Body mass index (BMI), total cholesterol, and blood pressure (BP) in the most recent clinic visit prior to conception or first trimester were used to determine CV health (ideal, intermediate, or poor health) based on AHA definitions. Outcomes included preterm birth, gestational age at birth, and small for gestational age (SGA). Multivariable linear and logistic regression models with generalized estimating equations estimated the association of each CV health factor and outcome. Results. The analysis included 309 live births. There were 95 preterm births (31%), and of the 293 pregnancies with birth weights, 18% were SGA. Ideal BMI, total cholesterol, and BP were reported in 56%, 85%, and 51% of pregnancies, respectively. Intermediate BMI was associated with decreased odds of SGA (OR 0.26, 95% CI 0.11-0.63), adjusted for race and prednisone use. Intermediate/poor total cholesterol was associated with increased odds of preterm birth (OR 2.21, 95% CI 1.06-4.62). Intermediate/poor BP was associated with decreased gestational age at birth (β -0.96, 95% CI -1.62 to -0.29). Conclusion. Poor/intermediate preconception CV health affects pregnancy outcomes of preterm birth and SGA infants among women with SLE. Efforts to maintain BMI, total cholesterol, and BP within the recommended ideal range prior to pregnancy is important to improve pregnancy outcomes in women with SLE

Effect of pregnancy on disease flares in patients with systemic lupus erythematosus

Objective: Prior studies found conflicting results about whether lupus is likely to flare during or after pregnancy. Using a large cohort of pregnant and non-pregnant women with lupus, we estimated the effect of pregnancy on disease flares in systemic lupus erythematosus. Methods: Data were collected in the Hopkins Lupus Cohort 1987-2015. Women aged 14-45 years with >1 measurement of disease activity were included. The time-varying exposures were classified as pregnancy, postpartum or non-pregnant/non-postpartum periods. Flares were defined as: (1) change in Physician Global Assessment (PGA)≥1 from previous visit and (2) change in Safety of Estrogens in Lupus National Assessment-Systemic Lupus Erythematosus Disease Activity Index (SELENA-SLEDAI)≥4 from previous visit. A stratified Cox model estimated HRs with bootstrap 95% CIs. Results: There were 1349 patients, including 398 pregnancies in 304 patients. There was an increased rate of flare defined by PGA during pregnancy (HR: 1.59; 95% CI 1.27 to 1.96); however, this effect was modified by hydroxychloroquine (HCQ) use, with the HR of flares in pregnancy compared with non-pregnant/non-postpartum periods estimated to be 1.83 (95% CI 1.34 to 2.45) for patients with no HCQ use and 1.26 (95% CI 0.88 to 1.69) for patients with HCQ use. The risk of flare was similarly elevated among non-HCQ users in the 3 months postpartum, but not for women taking HCQ after delivery. Conclusions: Our study supports and extends previous findings that the incidence of flare is increased during pregnancy and within the 3 months postpartum. Continuing HCQ, however, appeared to mitigate the risk of flare during and after pregnancy

Gestational weight gain in women with systemic lupus erythematosus

Objective The objective of this study was to estimate the proportion of pregnant women with systemic lupus erythematosus meeting Institute of Medicine guidelines for gestational weight gain and determine correlates of adherence to guidelines. Methods Singleton, live births in the Hopkins Lupus Pregnancy Cohort 1987-2015 were included. Pre-pregnancy weight was the weight recorded 12 months prior to pregnancy/first trimester. Final weight was the last weight recorded in the third trimester. Adherence to Institute of Medicine guidelines (inadequate, adequate, or excessive) was based on pre-pregnancy body mass index. Fisher's exact test and analysis of variance determined factors associated with not meeting guidelines. Stepwise selection estimated predictors of gestational weight gain. Results Of the 211 pregnancies, 34%, 24% and 42% had inadequate, adequate and excessive gestational weight gain, respectively. In exploratory analyses, differences in Institute of Medicine adherence were observed by pre-pregnancy body mass index, race, elevated creatinine during pregnancy and pre-pregnancy blood pressure. Odds of inadequate and excessive gestational weight gain increased 12% with each 1 kg/m2 increase in pre-pregnancy body mass index. Lower maternal education was associated with increased odds of inadequate and excessive gestational weight gain. Conclusions As in the general population, most women with systemic lupus erythematosus did not meet Institute of Medicine guidelines. Our results identified predictors of gestational weight gain to aid in targeted interventions to improve guideline adherence in this population

Meal patterning and the onset of spontaneous labor

Background: There is a lack of consensus in the literature about the association between meal patterning during pregnancy and birth outcomes. This study examined whether maternal meal patterning in the week before birth was associated with an increased likelihood of imminent spontaneous labor. Methods: Data came from 607 participants in the third phase of the Pregnancy, Infection, and Nutrition Study (PIN3). Data were collected through an interviewer-administered questionnaire after birth, before hospital discharge. Questions included the typical number of meals and snacks consumed daily, during both the week before labor onset and the 24-hour period before labor onset. A self-matched, case-crossover study design examined the association between skipping one or more meals and the likelihood of spontaneous labor onset within the subsequent 24 hours. Results: Among women who experienced spontaneous labor, 87.0% reported routinely eating three daily meals (breakfast, lunch, and dinner) during the week before their labor began, but only 71.2% reported eating three meals during the 24-hour period before their labor began. Compared with the week before their labor, the odds of imminent spontaneous labor were 5.43 times as high (95% CI: 3.41-8.65) within 24 hours of skipping 1 or more meals. The association between skipping 1 or more meals and the onset of spontaneous labor remained elevated for both pregnant individuals who birthed early (37-<39 weeks) and full-term (≥39 weeks). Conclusions: Skipping meals later in pregnancy was associated with an increased likelihood of imminent spontaneous labor, though we are unable to rule out reverse causality