Marion Dietrich

The Effect of Breakfast Type on Total Daily Energy Intake and Body Mass Index: Results from the Third National Health and Nutrition Examination Survey (NHANES III)

Objective: The objective of this study was to investigate the relationship between breakfast type, energy intake and body mass index (BMI). We hypothesized not only that breakfast consumption itself is associated with BMI, but that the type of food eaten at breakfast also affects BMI. Methods: Data from the Third National Health and Nutrition Examination Survey (NHANES III), a large, population-based study conducted in the United States from 1988 to 1994, were analyzed for breakfast type, total daily energy intake, and BMI. The analyzed breakfast categories were “Skippers,” “Meat/eggs,” “Ready-to-eat cereal (RTEC),” “Cooked cereal,” “Breads,” “Quick Breads,” “Fruits/vegetables,” “Dairy,” “Fats/sweets,” and “Beverages.” Analysis of covariance was used to estimate adjusted mean body mass index (BMI) and energy intake (kcal) as dependent variables. Covariates included age, gender, race, smoking, alcohol intake, physical activity and poverty index ratio. Results: Subjects who ate RTEC, Cooked cereal, or Quick Breads for breakfast had significantly lower BMI compared to Skippers and Meat and Egg eaters (p ≤ 0.01). Breakfast skippers and fruit/vegetable eaters had the lowest daily energy intake. The Meat and Eggs eaters had the highest daily energy intake and one of the highest BMIs. Conclusions: This analysis provides evidence that skipping breakfast is not an effective way to manage weight. Eating cereal (ready-to-eat or cooked cereal) or quick breads for breakfast is associated with significantly lower body mass index compared to skipping breakfast or eating meats and/or eggs for breakfast.

The Effect of Folate Fortification of Cereal-Grain Products on Blood Folate Status, Dietary Folate Intake, and Dietary Folate Sources among Adult Non-Supplement Users in the United States

Objective: Since January 1998, the Federal Drug Administration has required folic acid fortification of all enriched cereal-grain products in the U.S. This program intended to increase folic acid intake among women of childbearing age in order to decrease their risk of pregnancies affected by neural tube defects. The aim of this study was to explore the changes in serum and erythrocyte folate status of the adult U.S. population following folic acid fortification of enriched cereal-grain products and to explore accompanying changes in food sources and dietary total folate intake. Methods: We compared data from two National Health and Nutrition Examination Surveys (NHANES): NHANES III, conducted during 1988 to 1994, reflecting the time prior to folate fortification, and NHANES 1999–2000, reflecting the time period after fortification. Results: Mandatory folic acid fortification led to significant increases in both serum and erythrocyte folate concentrations in all sex and age groups. In the overall study population the mean serum folate concentration increased more than two-fold (136%), from 11.4 nmol/L to 26.9 nmol/L, and the mean erythrocyte folate concentration increased by 57 percent, from 375 nmol/L to 590 nmol/L. Less than 10% of women of childbearing age reached the recommended erythrocyte folate concentration of greater than 906 nmol/L that has been shown to be associated with a significant reduction in neural tube defect (NTD) risk. After fortification, the category “bread, rolls, and crackers” became the single largest contributor of total folate to the American diet, contributing 15.6% of total intake, surpassing vegetables, which were the number one folate food source prior to fortification. Dietary intake of total folate increased significantly in almost all sex and age groups, except in females over 60 years of age. The mean dietary total folate intake of the study population increased by 76 μg/d (28%), from 275 μg/d to 351 μg/d. Conclusions: The fortification of enriched cereal-grain products with folic acid lead to a significant improvement of blood folate status of the overall adult, non-supplement using, US population. However, women of childbearing age may take folic acid supplements to reach erythrocyte folate levels that have been associated with decreased risk of NTDs.

A review: dietary and endogenously formed N-nitroso compounds and risk of childhood brain tumors.

Maternal dietary exposure to N-nitroso compounds (NOC) or to their precursors during pregnancy has been associated with risk of childhood brain tumors. Cured meat is one source of exposure to dietary NOC and their precursors. Most epidemiological studies that have examined the role of maternal consumption of cured meats during pregnancy have found a significant positive association between maternal intake of cured meat and the risk of childhood brain tumor (CBT). NOC consist of two main groups, N-nitrosamines and N-nitrosamides. The carcinogenicity profiles of NOC suggest that N-nitrosamides rather than N-nitrosamines are the compounds that may be associated with CBT and that they should be investigated more closely in epidemiological studies. We present a review of the chemical and carcinogenic properties of NOC in connection with the findings of case–control studies. This approach may be helpful in determining the essential information that must be collected in future epidemiological studies on CBT.

Intraindividual variability of plasma antioxidants, markers of oxidative stress, C-reactive protein, cotinine, and other biomarkers

Background: Within-person variability in biomarkers results in random error that can attenuate estimates of association. Little information on such variability is available for a number of nutrition-related biomarkers. Methods: Blood samples obtained 2 to 4 weeks apart were analyzed for tocopherols, carotenoids, ascorbate, lipids, cotinine, C-reactive protein, and oxidative stress. Subjects (n = 206 men and women, mean age 45.4 years) were either smokers or passively exposed to smoke. We calculated intraindividual and interindividual variability and the number of measurements required to reduce attenuation. Results: For most biomarkers, 2 measurements would be required to limit the attenuation of correlation coefficients to no lower than 90% of the true correlation. If only one measurement were obtained, observed correlations would be approximately 80–88% of true correlations. For regression coefficients, 3 or 4 measures would be required. Exceptions were ascorbic acid and malondialdehyde, for which a single measure resulted in little attenuation. Conclusions: For most serum markers, collection of 2 or more measurements per person is desirable to increase the ability to detect associations between biomarkers and health-related variables. If only one measure is possible, sample sizes should be planned to permit detection of associations that are likely to be observed, not the theoretical true associations. The results of this study, in which measurements were obtained 2 to 4 weeks apart, are relevant for epidemiologic research in which the exposure of interest is the subject’s baseline or current status. It is likely that within-person variability would be greater over a period of months or years.

Associations between apolipoprotein E genotype and circulating F2-isoprostane levels in humans.

Apolipoprotein E (apoE), an important determinant of plasma lipoprotein metabolism, has three common alleles (ε2, ε3, and ε4). Population studies have shown that the risk of diseases characterized by oxidative damage, such as coronary heart disease and Alzheimer’s disease, is significantly higher in ɛ4 carriers. We evaluated the association between apoE genotypes and plasma F2-isoprostane levels, an index of lipid peroxidation, in humans. Two hundred seventy-four healthy subjects (104 males, 170 females; 46.9±13.0 yr; 200 whites, 74 blacks; 81 nonsmokers, 64 passive smokers, and 129 active smokers) recruited for a randomized clinical antioxidant intervention trial were included in this analysis. ApoE genotype was determined by PCR and restriction enzyme digestion. Free plasma F2-isoprostane was measured by GC-MS. Genotype groups were compared using multiple regression analysis with adjustment for sex, age, race, smoking status, body mass index, plasma ascorbic acid, and β-carotene. Subjects with ε3/ε4 and ε4/ε4 genotype (ε4-carriers) and with ε2/ε3 and ε3/ε3 (non-ε4-carriers) were pooled for analysis. In subjects with high cholesterol levels (total cholesterol above 200 mg/dl), plasma F2-isoprostane levels were 29% higher in ε4 carriers than in non-ε4-carriers (P=0.0056). High-cholesterol subjects that are ε4 carriers have significantly higher levels of lipid peroxidation as assessed by circulating F2-isoprostane levels.

What Is the Average Effect on Energy, Macronutrient, and Micronutrient Intake Whenever Americans Substitute Plant Protein for Beef or Pork?

Risk for a number of chronic diseases could be diminished if animal fat and cholesterol were decreased and fiber intake was increased. Meats are high in animal fat, such as saturated fat and cholesterol, and are major sources of these nutrients in the American diet. We conducted a simulation study in which we investigated the effect of the hypothetical substitution of plant protein for beef and pork products. We found that such a substitution would create a more favorable macronutrient profile with regard to fat, cholesterol, and fiber, and would lead to lower energy intake for the US population. No negative effects on micronutrient profiles, except moderately for zinc, were observed. In the context of the obesity epidemic facing Americans today, even a modest reduction in calorie consumption accompanying such a dietary change would be desirable.