Nature of dietary reporting by adults in the third National Health and Nutrition Examination Survey, 1988-1994

OBJECTIVE: Low reporting of food intake is an acknowledged problem in dietary assessments; however, differences in food intake relative to reporting status are poorly understood. This study examined the relation of a measure of dietary reporting status with the nature of food intake reported by adults in the third National Health and Nutrition Examination Survey. METHODS: Subjects were 6948 women and 6452 men, 20 years of age or older, with a complete and reliable 24-hour dietary recall. The ratio of reported energy intake to estimated basal energy expenditure (EI/BEE) was computed as a measure of dietary reporting status. The independent relation of EI/BEE ratio with 1) the amount, number, and energy density of nutrient-dense and low-nutrient-dense foods, 2) the number of reported eating occasions, 3) macro- and micronutrient intake and 4) serum concentrations of folate, ascorbate and carotenoids were examined using gender-specific multiple regression models. RESULTS: The EI/BEE ratio related positively with the amount, number and energy density of both nutrient-dense and low-nutrient-dense foods, and grams of alcoholic beverages. The EI/BEE ratio was an independent negative predictor of serum folate, ascorbate and alpha-carotene concentrations confirming the underreporting of food sources of these nutrients. The relative odds of reporting < or = 30% of energy as fat or < 10% of energy as saturated fat decreased with ratio of EI/BEE; however, the odds of reporting all five food groups or meeting the recommended intake of selected micronutrients increased with EI/BEE. CONCLUSIONS: The quantity and the quality of food intake reported in the 24-hour recall in NHANES III differed in relation to the ratio of EI/BEE.     

Association of self-perceived body weight status with dietary reporting by U.S. teens

OBJECTIVE: Children's self perception of body weight and the medical definition of obesity show poor correlation. This study examined the independent associations of body mass index (BMI) and self-perceived weight status (considered self over-, under-, or right weight) with food reporting, nutrient intake estimates, and biomarkers of dietary exposure. RESEARCH METHODS AND PROCEDURES: Dietary (one 24-hour recall), anthropometric, and biochemical data were from the third National Health and Nutrition Examination Survey (1269 boys and 1385 girls, ages 12 to 18 years). Sex-specific multiple regression analyses were used to determine the association of BMI and self-perceived body weight status with reported intakes of energy, macronutrients, low-nutrient-dense foods, micronutrients, and serum concentrations of selected vitamins and carotenoids. RESULTS: Reported intakes of energy, macronutrients, number of eating occasions, percentage of energy from low-nutrient-dense foods, likelihood of meeting the standard of intake of micronutrients, and biomarkers were not different among boys and girls who perceived themselves as overweight relative to those who perceived themselves at the right weight (p > 0.05). In boys, BMI was a negative predictor of percentage of energy from low-nutrient-dense foods (p = 0.004) and intake of ascorbic acid (p = 0.04). BMI was inversely related to serum concentrations of most carotenoids (p < or = 0.002). DISCUSSION: Perceiving oneself as overweight was not associated with reporting of low-nutrient-dense foods, macronutrients, micronutrients, and biomarker status; BMI, however, was a significant predictor of several outcomes.     

UNDERESTIMATION OF ENERGY INTAKE USING 24-HOUR RECALL BY KOREAN URBAN ELDERS

To investigate the underreporting of total energy intake, we analyzed the one-day dietary intake data collected by 24-hour recall method from 381 Seoul- and Ansung-dwelling older adults (≥60y) in Korea. Underreporting was addressed by computing the ratio of energy intake (EI) to the estimated basal metabolic rate (BMRest) from age- and gender-specific equations of Schofield. EI:BMRest ratio was found to be 1.41 for men and 1.22 for women, with about 12 percent of men and 19 percent of women classified as under reporters. Underreporting of energy intake was higher in men who were trying to lose weight, smokers, women who consumed alcohol, and in both sexes who were in poor health or had suffered from depression in the last year. For men, the most significant variables to predict the ratio of energy intake to estimated basal metabolic rate (EI: BMRest) were age and attempts to lose weight, whereas smoking, weight status, and education were most significant for women.     

UNDERESTIMATION OF ENERGY INTAKE USING 24-HOUR RECALL BY KOREAN URBAN ELDERS

To investigate the underreporting of total energy intake, we analyzed the one-day dietary intake data collected by 24-hour recall method from 381 Seoul- and Ansung-dwelling older adults (≥60y) in Korea. Underreporting was addressed by computing the ratio of energy intake (EI) to the estimated basal metabolic rate (BMRest) from age- and gender-specific equations of Schofield. EI:BMRest ratio was found to be 1.41 for men and 1.22 for women, with about 12 percent of men and 19 percent of women classified as under reporters. Underreporting of energy intake was higher in men who were trying to lose weight, smokers, women who consumed alcohol, and in both sexes who were in poor health or had suffered from depression in the last year. For men, the most significant variables to predict the ratio of energy intake to estimated basal metabolic rate (EI: BMRest) were age and attempts to lose weight, whereas smoking, weight status, and education were most significant for women.     

Diet and physical activity behaviors among Americans trying to lose weight: 2000 Behavioral Risk Factor Surveillance System

OBJECTIVE: To examine the prevalence and correlates of trying to lose weight among U.S. adults, describe weight loss strategies, and assess attainment of recommendations for weight control (eating fewer calories and physical activity). RESEARCH METHODS AND PROCEDURES: This study used the Behavioral Risk Factor Surveillance System, a state-based telephone survey of adults > or =18 years of age (N = 184,450) conducted in the 50 states, the District of Columbia, and Puerto Rico in 2000. RESULTS: The prevalence of trying to lose weight was 46% (women) and 33% (men). Women reported trying to lose weight at a lower BMI than did men; 60% of overweight women were trying to lose weight, but men did not reach this level until they were obese. Adults who had a routine physician checkup in the previous year and reported medical advice to lose weight vs. checkup and no medical advice to lose weight had a higher prevalence of trying to lose weight (81% women and 77% men vs. 41% women and 28% men, respectively). The odds of trying to lose weight increased as years of education increased. Among respondents who were trying to lose weight, approximately 19% of women and 22% of men reported using fewer calories and > or =150 min/wk leisure-time physical activity. DISCUSSION: A higher percentage of women than men were trying to lose weight; both sexes used similar weight loss strategies. Education and medical advice to lose weight were strongly associated with trying to lose weight. Most persons trying to lose weight were not using minimum recommended weight loss strategies.     

Plasma concentrations of carotenoids and vitamin C are better correlated with dietary intake in normal weight than overweight and obese elderly subjects

Carotenoid and vitamin C intakes, assessed by FFQ, have been positively associated with plasma concentrations in different populations. However, the influence of BMI on these associations has not been explored in detail. We explored in a cross-sectional study the relation between dietary carotenoid and vitamin C intakes, using a 135-item FFQ, with their plasma concentrations by BMI categories in 252 men and 293 women, 65 years and older. For men and women combined, significant (P < 0.05) Pearson correlations were observed between energy-adjusted dietary intakes and plasma concentrations (carotenoids adjusted for cholesterol) for: alpha-carotene 0.21, beta-carotene 0.19, lycopene 0.18, beta-cryptoxanthin 0.20 and vitamin C 0.36. Multiple linear regression analyses showed that the intake of carotenoids and vitamin C were significant predictors of their respective plasma concentration (P<0.01), and that BMI was inversely associated with plasma concentration of carotenoids (P< or =0.01) but not with plasma vitamin C. In addition, we observed significant interactions between BMI and the intakes of alpha-carotene and lutein + zeaxanthin, and to a lower extent beta-carotene, suggesting that these intakes in subjects with high BMI were not good predictors of their plasma concentration. The present data suggest that plasma carotenoids and vitamin C may be good markers of dietary intake in elderly subjects, but not so for alpha-carotene, beta-carotene and lutein + zeaxanthin in obese subjects.     

Correlates of under- and over-reporting of energy intake in Tehranians: body mass index and lifestyle-related factors

Under- and over-reporting of energy intake are problems in dietary intake assessment. This study was conducted to assess the correlates of under- and over-reporting of energy intake in Tehranians. Dietary data on 947 participants (415 males and 532 females) of the Tehran Lipid and Glucose Study was collected by trained interviewers using two 24-hour recalls. Weight and height were measured by digital scale and tape measure according to standard protocols and recorded to the nearest 100 g and 1cm, respectively. Under-, normal- and over-reporting of energy intake was defined as ratio of energy intake to basal metabolic rate (EI:BMR) <1.35, 1.35-2.39 and >or = 2.4, respectively. Mean +/- SD of age was 37.3 +/-14.6 and 32.9 +/-13.6 years for men and women, respectively. Men had higher EI:BMR than women (1.72 +/-0.44 vs 1.27 +/-0.44, P<0.001). EI and EI:BMR was highest in the youngest age groups in both sexes. The prevalences of under- and over-reporting were 31% and 5%, respectively. Fewer men than women underreported EI (19% vs 40%, P<0.001). The fraction of over-reporters was significantly higher in men than women (7% vs 3%, P<0.05). EI:BMR decreased with age. Under-reporters were older and had higher BMI than normal-reporters, but their educational level did not differ significantly. Over-reporters were younger and had lower BMI than normal-reporters, but their educational levels did not differ significantly. Most over-reporters had normal BMI. Smoking was more prevalent in over-reporters than in the normal-reporters (28% vs 19% in men and 6% vs 1% in women, P<0.01). The results showed a high prevalence of misreporting of energy intake in Tehran. This phenomenon is related to age, obesity and smoking habits.     

Evidence of nutrient dilution with high sugar intakes in older South Africans

Aims: To investigate the association between added sugar intake and (i) micronutrient intake, (ii) energy profiles and (iii) body mass index (BMI) of a sample of older South Africans. Methods: A sample of 200 free-living South Africans of mixed ancestry, aged 65 years and older and resident in Cape Town, was randomly drawn using a two-stage cluster design. Dietary intake was assessed using an interviewer-administered quantified food frequency questionnaire. Statistical analyses: Spearman correlation coefficients were used to investigate the associations between (i) sugar intake and (ii) total energy intake, and macro- and micronutrient intakes and BMI. Differences between the subgroups according to either tertiles of sugar or total energy intake were tested for significance at the P=0.05 level using analysis of variance (ANOVA ). Age was controlled for in the ANOVA models, according to two groups: 65–74 years and >75 years. Results: For both men and women, the proportion of energy provided by sugars did not differ across the tertiles of energy intake, suggesting that subjects with the highest energy intakes consumed greater quantities of all foods, rather than selecting foods high in sugar. An inverse association was found between the proportion of total energy provided by sugar and (i) the proportion of food energy provided by fat ( r=?0.53; P< 0.0001) and (ii) dietary fibre intake per 4.18 MJ/day ( r=?0.48; P<0.0001). In men the intake of thiamin, vitamin E, iron, zinc, copper and magnesium per 4.18 MJ significantly decreased ( P<0.05) as sugar intake as a percentage of total energy intake (%E) rose. In women, micronutrient intake expressed per 4.18 MJ showed a significant negative trend with sugar intakes as %E for all of the micronutrients investigated, except for vitamins D and E. Body mass index tended to decrease as sugar intake rose, but this difference did not reach significance. Conclusion: The findings of this study did not demonstrate an association between sugar intake and obesity in older South Africans. However, a nutrient-diluting effect of sugar intake on both micronutrient and fibre intake was observed and needs to be addressed in nutrition intervention strategies for this age group.     

Serum concentrations of beta-carotene and alpha-tocopherol are associated with diet, smoking, and general and central adiposity

BACKGROUND: Previous studies of associations between diet, obesity, and blood concentrations of alpha-tocopherol and beta-carotene have been equivocal. Furthermore, most studies used only body mass index (BMI) as an obesity measure. OBJECTIVES: Our objectives were to examine the associations between energy and nutrient intakes, alcohol consumption, tobacco use, and serum cholesterol and serum concentrations of alpha-tocopherol and beta-carotene, and to examine the associations between different measures of general and central adiposity and serum concentrations of alpha-tocopherol and beta-carotene. DESIGN: This was a cross-sectional, population-based study of 253 men and 276 women aged 46-67 y. Nutrient data were collected by a modified diet history method. Measures of obesity included BMI, percentage of body fat (impedance analysis), waist-to-hip ratio, and waist circumference. The associations between serum nutrient concentrations and the other factors were examined by multiple linear regression. RESULTS: Twenty-one percent of men and 34% of women used antioxidant supplements. The mean BMI was 26.1 in men and 25.4 in women. Serum beta-carotene concentration was positively associated with serum cholesterol concentration, fiber intake, and beta-carotene intake, and negatively associated with smoking and all measures of obesity. In men, serum beta-carotene concentration was not significantly associated with central adiposity after adjustment for body fat. Serum alpha-tocopherol concentration was positively correlated with serum cholesterol, obesity, and vitamin E intake. In women, serum alpha-tocopherol concentration was also positively associated with intakes of ascorbic acid and selenium. Serum alpha-tocopherol concentration was associated with central adiposity after adjustment for body fat. CONCLUSION: Serum beta-carotene and alpha-tocopherol concentrations have different associations with diet, smoking, general adiposity, and central adiposity.     

Micronutrient dilution associated with added sugar intake in elderly black South African women

OBJECTIVES: To investigate the association between added sugar and macronutrient and micronutrient intakes, and to assess whether added sugar intake is related to biochemical indices of nutritional status, Mini-Nutritional Assessment (MNA) score, body mass index (BMI) and performance on physical function tests. DESIGN: A cross-sectional, analytical study. SETTING AND SUBJECTS: Convenient sample of 285 institutionalised and community-dwelling black South African men and women aged 60+ y. METHODS: An interviewer-administered 24-h dietary recall and MNA were performed. Serum albumin, vitamin B12, ferritin, cholesterol, haemoglobin, red blood cell (RBC) folate and plasma vitamin C were measured. Handgrip strength, BMI, 'sit-to-stand' and 'get-up-and-go' tests were measured. Outcome variables were analysed according to tertiles of added sugar, in grams and as a percentage of total energy (% E). RESULTS: In each tertile of sugar intake, mean MNA score fell in the 'at-risk' classification. In women, energy, protein, % E protein, fibre, thiamin, riboflavin, niacin, vitamin B6, folate, pantothenic acid, biotin, vitamin C, calcium, iron, magnesium, phosphorus, zinc, copper and selenium intake were significantly lowest in subjects in the highest % E sugar tertile. In men, no differences were found for micronutrient intake according to tertiles of total added sugar or % E added sugar. Physical function declined with increasing sugar intake, and suboptimal RBC folate and plasma ascorbic acid status was associated with increasing sugar intake (in women). No relationship was found between added sugar intake and the very high prevalence (65%) of obesity in women. CONCLUSION: A nutrient-diluting effect of added sugars intake was demonstrated in elderly black South African women. Further studies in this population are required in order to develop food-based dietary guidelines, which include messages on added sugar intake.     

Consumption of energy-dense, nutrient-poor foods by adult Americans: nutritional and health implications. The third National Health and Nutrition Examination Survey, 1988-1994

BACKGROUND: Current dietary guidance recommends limiting the intake of energy-dense, nutrient-poor (EDNP) foods, but little is known about recent consumption patterns of these foods. OBJECTIVE: The contribution of EDNP foods to the American diet and the associated nutritional and health implications were examined. DESIGN: Data from the third National Health and Nutrition Examination Survey (n = 15611; age >/=20 y) were used. EDNP categories included visible fats, nutritive sweeteners and sweetened beverages, desserts, and snacks. The potential independent associations of EDNP food intake with intakes of energy, macronutrients, micronutrients, and serum vitamin, lipid, and carotenoid profiles were examined with linear and logistic regression procedures. RESULTS: EDNP foods supplied approximately 27% of energy intake; alcohol provided an additional 4%. The relative odds of consuming foods from all 5 food groups and of meeting the recommended dietary allowance or daily reference intake for protein and several micronutrients decreased with increasing EDNP food intake (P: < 0.0001). Energy intake and percentage of energy from fat were positively related to EDNP intake. Serum concentrations of vitamins A, E, C, and B-12; folate; several carotenoids; and HDL cholesterol were inversely related (P: 相似文献   

Underreporting of energy intake in an elderly German population.

OBJECTIVES: Within the longitudinal study on nutrition and health status in an aging population in Giessen, Germany (GISELA), the underreporters of energy intake (EI) were identified and characterized. METHODS: EI was assessed in 238 female and 105 male participants of the GISELA study (age range = 60-89 y) by means of a 3-day estimated dietary record developed especially for this study. Resting metabolic rate (RMR) was measured by indirect calorimetry after an overnight fast. EI was expressed as a multiple of RMR and subjects with an EI:RMR ratio below 1.073 were classified as underreporters. RESULTS: Mean EI:RMR was 1.62 +/- 0.46 in females and 1.53 +/- 0.46 in males; 7.6% of the females and 16.2% of the males were identified as underreporters. They showed lower levels of education and significantly greater body weight, body mass index, and fat mass than the adequate reporters. Further, underreporters stated more often than adequate reporters that they want to lose weight. Except for beta-carotene in males, reported nutrient intakes were significantly lower in underreporters than in adequate reporters. Carbohydrate and fat intake in both sexes, protein intake in females calculated as a percentage of EI, and vitamin and mineral densities were not affected by underreporting. CONCLUSIONS: The results indicate that underreporting of EI is related to a low educational level and greater body weight, body mass index, and fat mass and affects all nutrients. These findings should be considered when the association between nutrition and health status is investigated in the elderly.     

Carbohydrate intake is associated with diet quality and risk factors for cardiovascular disease in U.S. adults: NHANES III

OBJECTIVES: To determine if carbohydrate intake, as a % of energy, was related to diet quality and risk factors for cardiovascular disease (CVD) in adults in a cross-sectional and population-based study in the U.S. METHODS: Data from the third National Health and Nutrition Examination Survey (NHANES III, 1988-1994) were utilized. The nationally representative sample of the U.S. population (3,754 men, 4,074 women, ages 25 to 64 years) was divided into quintiles of carbohydrate intake (% of energy), which was examined in relation to risk factors for CVD: systolic blood pressure, body mass index (BMI), and concentrations of serum triglyceride, serum total and HDL cholesterol and plasma glucose. RESULTS: When covariates (age, ethnicity, smoking, alcohol intake and total energy intake) were adjusted in multivariate analyses, carbohydrate intakes (% of energy) were inversely associated with BMI and serum total cholesterol concentration in men and BMI in women and positively associated with serum triglyceride concentration in women. When total sugar intake (% of energy) was further controlled as a step to understand the quality of carbohydrate, carbohydrate intakes (% of energy) was a stronger predictor of BMI and plasma glucose in men and BMI in women. A high carbohydrate diet (>57.4% of energy in men and >59.1% of energy in women) was associated with a low serum HDL-cholesterol concentration in men and high serum triglyceride in women. CONCLUSION: Moderately high carbohydrate (50% to 55% of energy) diets were associated with low CVD risks with favorable lipid profiles.     

Serum levels assessment of vitamin A, E, C, B2 and carotenoids in malnourished and non-malnourished hospitalized elderly patients

AIMS & METHODS: Serum levels of vitamins A, E, C, B2 and carotenoids were determined in protein-energy malnourished (PEM, with body mass index, BMI<18.5 kg/m2) and non-PEM (BMI+/-18.5 kg/m2) hospitalized elderly (age > or = 65 years) patients, in the University Hospital of Faculty of Medicine of Ribeir?o Preto, S?o Paulo University. RESULTS: PEM (n=21) and non-PEM (n=106) patients were paired for age (73.6+/-7.3 vs. 71.6+/-5.6 years) and male percentage (65.1 vs. 52.4%). As expected, PEM elderly showed lower (P<0.05) body weight (median 43.1; range: 29.9-51.4 vs. 58.1; range: 45.7-143.5 kg), triceps skinfold (5.2+/-3.1 vs. 10.1+/-4.9 mm), and mid-arm muscle circumference (20.3+/-2.5 vs. 23.1+/-3.4 cm). Serum albumin (4.0+/-0.9 vs. 4.1+/-0.7 g/dl) and total lymphocytes count (1918.3+/-919 vs. 1842.7+/-862 mm(3)) were similar, respectively, among PEM and non-PEM patients. The percentage of biochemical riboflavin deficiency (58.8 vs. 56.2), low serum levels of vitamin A (28.6 vs. 29.6) and vitamin E (18.7 vs. 25) were similar, respectively, between PEM and non-PEM groups. The prevalence of low serum levels of water soluble vitamins was higher (P<0.01) in malnourished elderly than in the non-PEM group (ascorbic acid, 80.9 vs. 56.7%, and carotenoids, 14.3 vs. 3%, respectively).CONCLUSIONS: These results suggest that hospitalized malnourished elderly show high percentage of low water soluble vitamin serum levels, a phenomenon possibly linked to decreased food intake, especially fruits and vegetables.     

Associations between added sugars and micronutrient intakes and status: further analysis of data from the National Diet and Nutrition Survey of Young People aged 4 to 18 years

Added sugars are often viewed as 'empty calories', negatively impacting micronutrient intakes, yet reviews consider the evidence inconclusive. This study aimed to quantify associations between dietary added sugars (as a percentage of energy) and micronutrient intake and biochemical status in the National Diet and Nutrition Survey. Using data from 1688 British children aged 4-18 years who completed 7 d weighed dietary records in 1997, micronutrient intakes were examined across quintiles of added sugars. After excluding low energy reporters, mean dietary intakes of most nutrients exceeded the reference nutrient intake, except for zinc. Compared with quintile 1 (9% added sugars), high consumers in quintile 5 (23% added sugars) had micronutrient intakes ranging from 24% lower to 6% higher (mean 14% lower). Zinc intakes in quintile 1 v. quintile 5 averaged 93% v. 78% of reference nutrient intake; magnesium 114% v. 94%; iron 115% v. 100%; and vitamin A 111% v. 92%, respectively. Plasma levels of magnesium, zinc and carotenoids did not vary across quintiles, but weak negative correlations were observed with serum ferritin and transferrin saturation. Plasma selenium was inversely correlated with added sugars (r -0.17; P < 0.0001) but there was no association with glutathione peroxidase. The impact of added sugars on micronutrient intakes appears modest overall but may have relevance for children consuming inadequate amounts of nutrient-rich foods coupled with a diet high in added sugars (approximately 23%). Further work is needed to explore the impact of different sources of added sugars and to refine assessments of inadequate intakes and status.     

Perceived health risk of excess body weight among overweight and obese men and women: differences by sex

OBJECTIVES: To describe perceptions of health risk from excess body weight among adults, and assess if lack of perceived risk was associated with trying to lose weight. METHODS: Sex-specific logistic regression models were used to determine odds of disagreement that one's weight is a health risk and odds of trying to lose weight among overweight (BMI=25.0-29.9 kg/m(2), n=1296) and obese (BMI> or =30 kg/m(2), n=1335) adult participants in the 2004 Styles' surveys. RESULTS: Men were more likely than women to disagree their body weight was a health risk (among the overweight, 62% vs. 43%; the obese 20% vs. 14% obese). Disagreement with risk was associated with good health status and race/ethnicity among both sexes and lower education and income among women. Odds of currently trying to lose weight were significantly lower among obese men who disagreed, and overweight men and women who were neutral or disagreed that their body weight was a health risk. CONCLUSIONS: Many overweight and obese adults do not perceive their weight to be a health risk; this perception was associated with lower prevalence of trying to lose weight, particularly among men. Discussion by clinicians about the health risks of excess weight may alter perceived risk and help promote weight loss efforts.     

Intakes of calcium and vitamin d predict body mass index in the population of Northern Norway

This study was designed to investigate whether there is any association between body mass index (BMI) and life-style factors, with a special emphasis on calcium and vitamin D intakes. In 1994/1995, men (n = 9252) and women (n = 9662) participated in the fourth Troms? study and completed the food-frequency and life-style factor questionnaires. We measured BMI, coffee and alcohol consumption, physical activity, smoking, and calcium and vitamin D intakes. A negative association between physical activity, smoking and BMI, and a positive association between BMI and coffee intake were found in both sexes (P < 0.001). BMI and calcium intake were positively related in men (P < 0.001), but not in women. BMI and vitamin D intake were negatively associated in both sexes (P < 0.001), which to our knowledge has not been reported before. The lowest quartile of vitamin D intake was an independent predictor of obesity (defined as BMI >30 kg/m(2)) in men and women (P < 0.001 in both genders), resulting in odds ratios of 2.24 [95% confidence interval (CI) 1.80, 2.80] in men and 1.51 (95% CI 1.23, 1.85) in women compared with the highest quartile. In conclusion, calcium and vitamin D intakes may have opposing effects on body weight, which is difficult to explain given current knowledge of calcium metabolism.     

Correlates of serum alpha- and gamma-tocopherol in the Women's Health Initiative

PURPOSE: There is increasing evidence that vitamin E (primarily alpha- and gamma-tocopherol) may reduce the risk of cardiovascular disease and some cancers, therefore it is important to understand factors that influence blood levels.METHODS: The correlates of serum alpha- and gamma-tocopherol were investigated among participants in the Women's Health Initiative (WHI), a 40-site disease prevention trial. Subjects were 1047 postmenopausal women aged 50-79 years, who provided fasting blood specimens and detailed information on diet, supplement use, and other factors at entry to the study (1994-96).RESULTS: Total serum cholesterol and triglycerides were highly correlated with serum alpha- and gamma-tocopherol concentrations and were controlled for in all analyses along with age, ethnicity and body mass index (BMI). Alpha and gamma-tocopherol were strongly negatively correlated (partial r = -0.69). The strongest predictor of serum tocopherols was average daily intake of vitamin E from supplements (partial r = 0.60 for alpha, r = -0.54 for gamma). Other factors associated with increased alpha- and/or decreased gamma-tocopherol concentrations were serum retinol and carotenoids, supplemental vitamin C, alpha-tocopherol intake from food, dietary fiber, and Hispanic ethnicity. Factors associated with lower alpha- and/or higher gamma-tocopherol concentrations included gamma-tocopherol intake from food, total fat intake, and BMI. Age, income, hormone use, and geographic location were "spuriously" associated with serum tocopherol levels through their association with supplement use, i.e., there was no such association among the subset of women not taking supplements.CONCLUSIONS: Vitamin E intake from supplements and BMI are the major independent predictors of serum tocopherol levels in women, whereas dietary factors only play a small role.     

Associations between obesity and serum lipid-soluble micronutrients among premenopausal women

Elucidating potential pathways that micronutrients may reduce/promote chronic disease may contribute to our understanding of the underlying etiology of disease and their utility as markers of risk. In the current study, we examined associations of serum lipid-soluble micronutrients with body mass index (BMI). We hypothesized that obesity may differentially influence serum micronutrient levels, thereby affecting risk for chronic disease incidence and mortality. Baseline serum samples from 180 premenopausal women from a nutritional trial were analyzed for leptin, C-reactive protein, 25-hydroxyvitamin D, carotenoids, and tocopherols. Participants were stratified into normal-weight (18.5-24.9), overweight (25-29.9), and obese (≥30) subgroups by BMI (in kilograms per square meter). Differences in serum biomarkers among BMI subgroups were adjusted for Asian ethnicity and smoking status. As expected, obese individuals had significantly higher serum levels of leptin and C-reactive protein (Ps < .05) compared with normal-weight women. γ-Tocopherol levels were significantly higher in obese individuals (P < .05), whereas α-tocopherol levels did not differ among BMI subgroups. Serum levels of 25-hydroxyvitamin D and carotenoids (except lycopene) were significantly lower in obese than in normal-weight women (Ps < .05). The associations between BMI and carotenoids were independent of dietary intake. The obesity-associated reduction for total provitamin A carotenoids (45%) was approximately 3-fold greater than that observed for non–provitamin A carotenoids (16%). Our results indicate potential influences of obesity on serum levels of lipid-soluble micronutrients and suggest that metabolism of provitamin A carotenoids may contribute to the differences observed.