Effects of Mercury on Health and First-Year Survival of Free-Ranging Great Egrets (Ardea albus) from Southern Florida

The objectives of this study were to determine whether elevated mercury (Hg) concentrations have a negative impact on the health and survival of nestling and juvenile free-ranging great egrets (Ardea albus) from southern Florida. During 1994, when health and survival was monitored in a cohort of young birds with naturally variable concentrations of Hg, packed cell volume was positively correlated with blood Hg concentrations, and high Hg concentration in blood was not related to the probability of surviving during the first 10.5 months of life. During 1995, 70 first-hatched great egret chicks were included in a Hg field-dosing experiment to compare the effects of elevated Hg on health and survival. Birds were dosed while in the nest orally every 2.5 days for 15 days with 0.5 mg of methyl mercury chloride (MeHgCl) for an estimated intake of 1.54 mg MeHgCl/kg food intake. These birds were compared with controls, which received an estimated 0.41 mg MeHgCl/kg food. No differences were observed in health parameters or in the probability of surviving during the first 8 months of age between egrets that were dosed with Hg and those that were not. A likely explanation for the lack of any effects on health and survival between both groups could be that chicks at this age were eliminating most of the dietary Hg through the production of new feathers. Received: 10 November 1998/Accepted: 8 April 1999     

Effects of methylmercury exposure on the immune function of juvenile common loons (Gavia immer)

We conducted a dose-response laboratory study to quantify the level of exposure to dietary Hg, delivered as methylmercury chloride (CH3HgCl), that is associated with suppressed immune function in captive-reared common loon (Gavia immer) chicks. We used the phytohemagglutinin (PHA) skin test to assess T-lymphocyte function and the sheep red blood cell (SRBC) hemagglutination test to measure antibody-mediated immunity. The PHA stimulation index among chicks receiving dietary Hg treatment did not differ significantly from those of chicks on the control diet (p = 0.15). Total antibody (immunoglobulin [Ig] M [primary antibody] + IgG [secondary response]) production to the SRBC antigen in chicks treated with dietary methylmercury (MeHg), however, was suppressed (p = 0.04) relative to chicks on control diets. Analysis indicated suppression of total Ig production (p = 0.025 with comparisonwise alpha level = 0.017) between control and 0.4 microg Hg/g wet food intake treatment groups. Furthermore, the control group exhibited a higher degree of variability in antibody response compared to the Hg groups, suggesting that in addition to reducing the mean response, Hg treatment reduced the normal variation attributable to other biological factors. We observed bursal lymphoid depletion in chicks receiving the 1.2 microg Hg/g treatment (p = 0.017) and a marginally significant effect (p = 0.025) in chicks receiving the 0.4 microg Hg/g diet. These findings suggest that common loon chick immune systems may be compromised at an ecologically relevant dietary exposure concentration (0.4 microg Hg/g wet wt food intake). We also found that chicks hatched from eggs collected from low-pH lakes exhibited higher levels of lymphoid depletion in bursa tissue relative to chicks hatched from eggs collected from neutral-pH lakes.     

Reference levels of blood mercury and association with metabolic syndrome in Korean adults

Purpose

Mercury (Hg) is a nonessential and toxic metal that is widely distributed in the environment. This study was performed to estimate the representative blood Hg level, to determine the contributing factors to Hg exposure, and to analyze the association of blood Hg with metabolic syndrome in Korean adults.

Methods

Mercury exposure is assessed by total Hg concentration in blood. A total of 2,114 healthy adults who have not been exposed to Hg occupationally were sampled by the multistaged, sex-, and age-stratified probability method. Information was collected regarding the subjects’ demographic characteristics, lifestyles, and past medical history. The participants then underwent physical examination and blood sampling.

Results

The geometric mean concentration of Hg in whole blood was 3.90 μg/L, which was significantly influenced by sex, age, smoking, alcoholic consumption, residence area, and seafood intake after adjustment for confounders. Significant increases in body mass index, waist circumference, diastolic blood pressure, total cholesterol, and triglyceride were observed according to the blood Hg levels after adjustment for covariates. Also, Hg exposure was significantly associated with metabolic syndrome and their components such as obesity and increased fasting glucose.

Conclusion

The blood Hg level in Korean adults is higher than that in USA and other Western countries, while it is similar to or lower than that in other Asian countries. The blood Hg level is influenced by sociodemographic factors and individual lifestyles including dietary habits. Furthermore, blood Hg is associated with metabolic syndrome, in which Hg exposure may play a role as a possible risk factor for cardiovascular diseases.     

Inadequate Intake of Dietary Fibre in Adolescents,Adults, and Elderlies: Results of Slovenian Representative SI. Menu Study

Dietary fibre has proven to promote healthy body mass and reduce the risk of non-communicable diseases. To date, in Slovenia, there were only a few outdated studies of dietary fibre intake; therefore, we explored the dietary fibre intake using food consumption data collected in the SI.Menu project. Following the EU Menu methodology, data were collected on representative samples of adolescents, adults, and elderlies using a general questionnaire, a food propensity questionnaire, and two 24 h recalls. The results indicate that the intake of dietary fibre in Slovenia is lower than recommended. The proportion of the population with inadequate fibre intakes (<30 g/day) was 90.6% in adolescents, 89.6% in adults, and 83.9% in elderlies, while mean daily fibre intakes were 19.5, 20.9, and 22.4 g, respectively. Significant determinants for inadequate dietary fibre intake were sex in adolescents and adults, and body mass index in adults. The main food groups contributing to dietary fibre intake were bread and other grain products, vegetables and fruits, with significant differences between population groups. Contribution of fruits and vegetables to mean daily dietary fibre intake was highest in elderlies (11.6 g), followed by adults (10.6 g) and adolescents (8.5 g). Public health strategies, such as food reformulation, promoting whole-meal alternatives, consuming whole foods of plant origin, and careful planning of school meals could beneficially contribute to the overall dietary fibre intake in the population.     

Blood pressure and urinary sodium in men and women: the Norfolk Cohort of the European Prospective Investigation into Cancer (EPIC-Norfolk)

BACKGROUND: Abundant evidence indicates that a high sodium intake is causally related to high blood pressure, but debate over recommendations to reduce dietary sodium in the general population continues. A key issue is whether differences in usual sodium intake within the range feasible in free-living populations have clinical or public health relevance. OBJECTIVE: We examined the relation between blood pressure and urinary sodium as a marker of dietary intake. DESIGN: This was a study of 23104 community-living adults aged 45-79 y. RESULTS: Mean systolic and diastolic blood pressure increased as the ratio of urinary sodium to creatinine increased (as estimated from a casual urine sample), with differences of 7.2 mm Hg for systolic blood pressure and 3.0 mm Hg for diastolic blood pressure (P < 0.0001) between the top and bottom quintiles. This trend was independent of age, body mass index, urinary potassium:creatinine, and smoking and was consistent by sex and history of hypertension. The prevalence of those with systolic blood pressure >/= 160 mm Hg halved from 12% in the top quintile to 6% in the bottom quintile; the odds ratio for having systolic blood pressure >/= 160 mm Hg was 2.48 (95% CI: 1.90, 3.22) for men and 2.67 (95% CI: 2.08, 3.43) for women in the top compared with the bottom quintile of urinary sodium. Estimated mean sodium intakes in the lowest and highest quintiles were approximately 80 and 220 mmol/d, respectively. CONCLUSIONS: Within the usual range found in a free-living population, differences in urinary sodium, an indicator of dietary sodium intake, are associated with blood pressure differences of clinical and public health relevance. Our findings reinforce recommendations to lower average sodium intakes in the general population.     

中老年人膳食硒与高血压关系的横断面研究

目的 探讨膳食硒摄入量与高血压的关系。方法 从湖南湘雅医院健康体检中心随机选取被体检人员为研究对象,测量身高、体重、血压等身体指标,利用食物频率调查问卷间接测量膳食硒摄入情况。采用t检验、χ2检验进行单因素分析,Logistic回归模型分析膳食硒与高血压的关系。结果 分析显示,性别、年龄、体质指数、糖尿病患病情况及膳食纤维摄入情况在高血压患者与非高血压患者间的差异均有统计学意义（均有P<0.05）。校正年龄、性别、吸烟、饮酒状况等相关因素后,结果显示:以硒摄入水平的最低分类（<27.51 mg/d）作为参照,最高分类（>55.81 mg/d）的OR（95% CI）为0.715（0.528~0.968）,高血压的患病率随着膳食硒摄入水平的升高而降低。结论 增加膳食硒摄入可以降低高血压的患病风险。     

Energy and nitrogen intake, expenditure and retention at 20 degrees in growing fowl given diets with a wide range of energy and protein contents

Heat production (HP) and the intake and retention of energy and nitrogen were measured at 20 degrees in growing female broiler fowl given diets with metabolizable energy (ME) contents ranging from 8 to 15 MJ/kg at each of two crude protein (nitrogen x 6.25; CP) contents (130 and 210 g/kg). ME intake was partially controlled by the birds, but increased by 30% over the range of dietary ME concentration. CP intake varied directly with dietary CP: ME ratio, indicating that control of energy intake took priority and that food intake did not increase in order to enhance amino acid intake on low-CP diets. Maintenance energy requirement and fasting HP were not affected by diet. Although the HP of fed birds was significantly affected by dietary energy source, there was no evidence for regulatory diet-induced thermogenesis as energy intake increased. Total energy retention doubled on the higher-energy diets as a result of increased intake and retention efficiency in the absence of any compensation by diet-induced thermogenesis. The proportion of energy retained as fat was negatively correlated with dietary CP: ME ratio. It was concluded that the growing female broiler fowl responded to large differences in energy intake and dietary CP concentration not by changes in rate of energy dissipation as heat but by changes in the quantity of energy retained and in the partition of retained energy between body protein and body fat.     

Nutritional Status and Food Habits of Middle-aged Adults in Selected Areas of Selangor

A food habits and health status study was carried out among 100 Malay adults aged 40 years and above. The study protocol incorporated anthropometric measurements, evaluation of food habits and determination of blood glucose, cholesterol and blood pressure. Mean body mass index (BMI) for men and women were 27.2 ± 4.2 kg/m2 and 27.0 ± 5.2 kg/m2 respectively, which on average showed that the subjects were overweight. Food habits evaluation indicated that rice, fish and vegetables were the foods consumed almost everyday by the majority of the subjects. Meat, dairy products and fruits were eaten once to three times per week. Food intake score for sugar and salt demonstrated that a majority of men and women consumed moderate amounts of these foods. Most subjects exercised twice to three times a week for 15 min per session. Blood glucose tests revealed a mean of 5.04 ± 1.60 mmol/l in men and 4.86 ± 2.10 mmol/l for women. Mean cholesterol for men was 5.06 ± 1.22 mmol/l while it was 4.90 ± 1.34 mmol/l in women. Mean systolic and diastolic blood pressure in men was normal of 127.69 ± 13.60 mm Hg dan 85.87 ± 7.97 mm Hg, while in women it was 127.42 ± 17.54 mm Hg, 83.53 ± 9.50 mm Hg. The mean value for glucose, cholesterol and blood pressure increased with age. The food habits of these adults were satisfactory; however blood test for the nutrients of interest exhibited an increasing trend towards blood pressure, blood cholesterol and glucose with age. Middle-aged adults should adapt to a more active lifestyle and be more cautious of their food habits. This is to ensure a healthy well being throughout their life span.     

A priori and a posteriori dietary patterns at the age of 1 year and body composition at the age of 6 years: the Generation R Study

Dietary patterns have been linked to obesity in adults, however, not much is known about this association in early childhood. We examined associations of different types of dietary patterns in 1-year-old children with body composition at school age in 2026 children participating in a population-based cohort study. Dietary intake at the age of 1 year was assessed with a food-frequency questionnaire. At the children’s age of 6 years we measured their body composition with dual-energy X-ray absorptiometry and we calculated body mass index, fat mass index (FMI), and fat-free mass index (FFMI). Three dietary pattern approaches were used: (1) An a priori-defined diet quality score; (2) dietary patterns based on variation in food intake, derived from principal-component-analysis (PCA); and (3) dietary patterns based on variations in FMI and FFMI, derived with reduced-rank-regression (RRR). Both the a priori-defined diet score and a ‘Health-conscious’ PCA-pattern were characterized by a high intake of fruit, vegetables, grains, and vegetable oils, and, after adjustment for confounders, children with higher adherence to these patterns had a higher FFMI at 6 years [0.19 SD (95 % CI 0.08;0.30) per SD increase in diet score], but had no different FMI. One of the two RRR-patterns was also positively associated with FFMI and was characterized by intake of whole grains, pasta and rice, and vegetable oils. Our results suggest that different a priori- and a posteriori-derived health-conscious dietary patterns in early childhood are associated with a higher fat-free mass, but not with fat mass, in later childhood.     

Food intake patterns and body mass index in older adults: a review of the epidemiological evidence

The relationship between food intake patterns and obesity remains unclear. The objective of the present review was to evaluate the current body of literature on food intake patterns of older adults and their associations with weight status, including obesity and waist circumference. Eleven observational studies were identified and reviewed. Diets characterized by more favorable dietary scores or indices were generally inversely related to body mass index. Results from data-driven approaches were inconsistent. Findings from this literature review suggest that there is no clear relationship between food intake patterns and body mass index or waist circumference in older adults. Limitations, including heterogeneity of food intake patterns and study populations, hinder the ability to make clear comparisons. Continued efforts to elucidate the relationship between food intake patterns and weight status indicators in older adults, including longitudinal analyses and use of novel statistical approaches for food intake pattern identification, are warranted.     

Food Intake Patterns and Body Mass Index in Older Adults: A Review of the Epidemiological Evidence

The relationship between food intake patterns and obesity remains unclear. The objective of the present review was to evaluate the current body of literature on food intake patterns of older adults and their associations with weight status, including obesity and waist circumference. Eleven observational studies were identified and reviewed. Diets characterized by more favorable dietary scores or indices were generally inversely related to body mass index. Results from data-driven approaches were inconsistent. Findings from this literature review suggest that there is no clear relationship between food intake patterns and body mass index or waist circumference in older adults. Limitations, including heterogeneity of food intake patterns and study populations, hinder the ability to make clear comparisons. Continued efforts to elucidate the relationship between food intake patterns and weight status indicators in older adults, including longitudinal analyses and use of novel statistical approaches for food intake pattern identification, are warranted.     

Response surface analyses of the effects of dietary protein on feeding and growth patterns in mice from weaning to maturity

Responses of food intake, protein intake, gross energy intake and body weight of mice from weaning to maturity to dietary protein level were studied. Thirteen groups of ddY male mice were fed purified diets covering the entire range (0-100%) of protein concentration on a gross energy basis for 68 d. The food intake and body weight data in each group were analyzed by nonlinear regression to obtain values of the six parameters in Parks' feeding and growth equations. These parameters, found as a function of the protein content of diet, were then used to construct the response surfaces of food intake and body weight over the dietary protein versus age space. At every protein level the daily energy intake rose rapidly with age to a plateau at about 7-14 d after weaning and was maintained throughout the experiment. Daily energy intake was independent of the dietary protein content except at very low dietary protein contents. Consequently, from 21 to 89 d of age daily protein intake was directly proportional to dietary protein level. These results imply that mice ate for energy rather than protein when fed diets varying in protein content in the range of 10-80%. Body weight as a function of time after weaning increased to a plateau at every dietary protein level, but the details of the pattern of growth were affected by the dietary protein level. Further, the response surface of body weight versus dietary protein level and age was analyzed to find the protein requirement of mice for maximal growth during a given interval from weaning.     

Tofu consumption and blood lead levels in young Chinese adults.

Tofu is a commonly consumed food in China. Tofu may interfere with lead absorption and retention because of its high calcium content. In this observational study, the authors examined whether dietary tofu intake was associated with blood lead levels among young adults in Shenyang, China. The analyses included 605 men and 550 women who completed baseline questionnaires and had blood lead measurements taken in 1996-1998 as part of a prospective cohort study on reproductive health. Mean blood lead levels were 13.2 microg/dl in men and 10.1 microg/dl in women. Blood lead levels were negatively associated with tofu intake in both genders. A linear trend test showed a 3.7% (0.5-microg/dl) decrease in blood lead level with each higher category of tofu intake (p = 0.003). The highest tofu intake group (> or =750 g/week) had blood lead levels 11.3% lower (95% confidence interval: 4.1, 18.0) than those of the lowest tofu intake group (<250 g/week). In all regression models, data were adjusted for gender, age, height, body mass index, district, cigarette smoking, alcohol drinking, education, occupation, use of vitamin supplements, season, and dietary intake of meat, fish, vegetables, eggs, and milk. In conclusion, the authors found a significant inverse dose-response relation between tofu consumption and blood lead levels in this Chinese population.     

Lead sources in human diet in Greenland

Although blood lead levels have declined in Greenland, they are still elevated despite the fact that lead levels in the Greenland environment are very low. Fragments of lead shot in game birds have been suggested as an important source of dietary exposure, and meals of sea birds, particularly eider, contain high concentrations of lead. In a cross-sectional population survey in Greenland in 1993-1994, blood lead adjusted for age and sex was found to be associated with the reported consumption of sea birds. Participants reporting less than weekly intake of sea birds had blood lead concentrations of approximately 75 microg/L, whereas those who reported eating sea birds several times a week had concentrations of approximately 110 microg/L, and those who reported daily intake had concentrations of 170 microg/L (p = 0.01). Blood lead was not associated with dietary exposure to other local or imported food items.     

Distribution and accumulation of mercury in tissues of captive-reared common loon (Gavia immer) chicks

We determined the distribution and accumulation of Hg in tissues of common loon (Gavia immer) chicks maintained for up to 15 weeks on either a control diet with no added methylmercury chloride (MeHgCl) or one containing either 0.4 or 1.2 microg Hg (as MeHgCl)/g wet-weight food. Total Hg and MeHg tissue concentrations were strongly positively correlated (r2 > 0.95) with the amount of Hg delivered to individual chicks throughout the course of the experiment. The pattern of differential Hg concentration in internal tissues was consistent within each treatment: Liver > kidney > muscle > carcass > brain. Feather Hg concentrations were consistently higher than those of internal tissues and represented an important route of Hg elimination. Feather mass accounted for 4.3% +/- 0.1% (average +/- standard error) of body mass, yet 27.3% +/- 2.6% of total Hg intake was excreted into feathers. Our calculations indicate that 26.7% +/- 4.9% of ingested Hg was not accounted for and, thus, either was never absorbed or was absorbed and subsequently eliminated in feces. With the additional excretion into feathers, 54% of ingested Hg was excreted. Demethylation was evident in the liver at all treatment levels and in the kidneys of chicks dosed at 1.2 microg Hg/g. Mercury concentrations were strongly positively correlated (r2 > or = 0.95) among internal tissues and with blood Hg concentration. Mercury concentrations of secondary feathers were moderately correlated (r2 = 0.82-0.93) with internal tissues. We supply regression models that may be used to provide perspective and a useful means of interpreting the variety of measures of Hg exposure reported in the literature.     

Calcium intake and blood pressure in seven Japanese populations

The relation between dietary calcium and blood pressure was examined in 1,928 men, ages 40-69 years, from five geographic and two occupational populations in Japan. Dietary calcium intake was estimated using 24-hour dietary recall in systematic samples of participants of population-based cardiovascular surveys from 1983 to 1987. The means of daily calcium intake of the study populations ranged from 449 to 695 mg, approximately 300 mg lower than the recommended US dietary calcium intake. Linear regression analyses were used to examine the relation between dietary calcium and blood pressure within each population, controlling for age, body mass index, alcohol consumption, and sodium intake. Total calcium intake was inversely associated with the systolic blood pressure level in each population, and the pooled estimate of the regression coefficients for millimeters of mercury of blood pressure per 100-mg increase in calcium intake was -0.54 (95% confidence interval -0.89 to -0.19). The inverse association between calcium intake and diastolic blood pressure was less consistent, and the pooled estimate did not reach statistical significance (-0.10, 95% confidence interval -0.34-0.14). Inverse associations existed for both dairy and nondairy food sources of calcium when analyzed separately, and the association was significant only for dairy calcium. Although a causal relation between dietary calcium and blood pressure cannot be established, these results suggest a possible public health implication in Japan of increasing calcium intake for the prevention and control of hypertension, where average dietary calcium intake is low.     

Overeating in America: association between restaurant food consumption and body fatness in healthy adult men and women ages 19 to 80

PURPOSE: To examine the association between the frequency of consuming restaurant food and body fatness in adults. RESEARCH METHODS AND PROCEDURES: Usual free-living dietary intake and the frequency of consuming food from seven different restaurant types (fried chicken, burger, pizza, Chinese, Mexican, fried fish, and "other") were assessed by food frequency questionnaire in 73 healthy men and women [ages 19 to 80, body mass index (BMI) 18 to 33]. In addition, body fatness (percent weight) was determined by hydrostatic weighing, and physical activity and other lifestyle parameters were assessed by questionnaire. The relationship between the frequency of consuming restaurant food and body fatness was determined after controlling for age, sex, and other confounders by using multiple regression techniques. RESULTS: Restaurant food consumption averaged 7.5+/-8.5 (Standard Deviation) times/month. After controlling for age and sex, the frequency of consuming restaurant food was positively associated with body fatness (partial r = 0.36, p = 0.003). The strength of this association did not change after controlling for education level, smoking status, and alcohol intake, but after additionally controlling for physical activity, the partial r increased to 0.42 (p = 0.004). Total daily intakes of energy, fat, and fiber were significantly associated with restaurant food consumption frequency (r = 0.59, 0.28, and -0.45, respectively, p = 0.02 to 0.0001). DISCUSSION: The frequency of consuming restaurant food was positively associated with increased body fatness in adults. The increasing proportion of household food income spent on food prepared away from home in the United States may therefore help explain the rising national prevalence of obesity.     

Relative influence of diet and physical activity on body composition in urban Chinese adults

BACKGROUND: The relative influence of diet and physical activity on body fatness remains uncertain. OBJECTIVE: The objective of the study was to investigate associations of dietary variables and physical activity with body fatness in urban Chinese adults. DESIGN: We conducted a cross-sectional study in 130 weight-stable men and women aged 35-49 y. Subjects were selected from upper and lower tertiles of dietary fat and physical activity on the basis of screening questionnaires. Dietary intake was assessed by weighed food intake, physical activity level (PAL) was calculated as the ratio of predicted total energy expenditure (TEE) to predicted resting energy expenditure, and body composition was measured with the use of (2)H(2)O. Reported energy intake and predicted TEE were validated against TEE determined with the use of (2)H(2)(18)O (n = 73). RESULTS: Body fatness was positively associated with dietary variety (ie, variety of ingredients) (partial r = 0.186, P = 0.039) and frequency of consuming restaurant foods (partial r = 0.237, P = 0.001) and negatively associated with PAL (partial r = -0.307, P = 0.001) in a multiple regression analysis that controlled for sex and confounders. The combined variance accounted for by dietary variety and restaurant food consumption (9.1%) was equivalent to that for PAL (9.4%). Neither dietary fat nor energy density predicted body fatness, but dietary energy density predicted within-subject day-to-day variation in reported energy intake (P < 0.001). CONCLUSIONS: Dietary variety, frequency of restaurant food consumption, and PAL significantly predicted body fatness in urban Chinese adults, but dietary fat did not. These findings support previous studies in US adults and suggest that dietary variables other than fat have an important influence on adult body composition.     

Nutrient intake and blood pressure: families of adult identical twins.

To investigate the relationship of dietary intake to blood pressure, 198 adults and 53 children who were members of 92 nuclear families completed a 3-day diet diary prior to an outpatient clinic examination for cardiovascular disease risk factors. Nutrient intake was significantly related to age and anthropometric variables in adults. Sodium and potassium intake were related to blood pressure in adults, but this relationship was no longer significant after adjustment for caloric intake. The diet and blood pressure relationships in children were less clear. Multiple linear regression techniques using age, anthropometric variables, and nutrient intake demonstrated that in adults age and skinfold were the principal determinants of blood pressure, but in children age and saturated fat intake were most likely to enter the equations. In comparisons of normotensive and hypertensive adults, there were no differences in the dietary intakes of these electrolytes. The results of this investigation underscore the complex interaction of nutrient intake with body size and age. Investigators who focus only on a few nutrients and fail to account for other sources of variation can be misled.     

Nutrient intake and blood pressure: families of adult identical twins

To investigate the relationship of dietary intake to blood pressure, 198 adults and 53 children who were members of 92 nuclear families completed a 3-day diet diary prior to an outpatient clinic examination for cardiovascular disease risk factors. Nutrient intake was significantly related to age and anthropometric variables in adults. Sodium and potassium intake were related to blood pressure in adults, but this relationship was no longer significant after adjustment for caloric intake. The diet and blood pressure relationships in children were less clear. Multiple linear regression techniques using age, anthropometric variables, and nutrient intake demonstrated that in adults age and skinfold were the principal determinants of blood pressure, but in children age and saturated fat intake were most likely to enter the equations. In comparisons of normotensive and hypertensive adults, there were no differences in the dietary intakes of these electrolytes. The results of this investigation underscore the complex interaction of nutrient intake with body size and age. Investigators who focus only on a few nutrients and fail to account for other sources of variation can be misled.