Food insufficiency, family income, and health in US preschool and school-aged children.

OBJECTIVES: This study investigated associations between family income, food insufficiency, and health among US preschool and school-aged children. METHODS: Data from the third National Health and Nutrition Examination Survey were analyzed. Children were classified as food insufficient if the family respondent reported that the family sometimes or often did not get enough food to eat. Regression analyses were conducted with health measures as the outcome variables. Prevalence rates of health variables were compared by family income category, with control for age and gender. Odds ratios for food insufficiency were calculated with control for family income and other potential confounding factors. RESULTS: Low-income children had a higher prevalence of poor/fair health status and iron deficiency than high-income children. After confounding factors, including poverty status, had been controlled, food-insufficient children were significantly more likely to have poorer health status and to experience more frequent stomachaches and headaches than food-sufficient children; preschool food-insufficient children had more frequent colds. CONCLUSIONS: Food insufficiency and low family income are health concerns for US preschool and school-aged children.

Energy and fat intakes of children and adolescents in the united states: data from the national health and nutrition examination surveys.

BACKGROUND: Dietary factors related to body weight and chronic disease risk are of interest because of recent increases in the prevalence of overweight. OBJECTIVE: Secular trends in energy and fat intakes of youths aged 2-19 y were assessed. Current intakes were compared with recommendations. DESIGN: Dietary 24-h recall data from the third National Health and Nutrition Examination Survey (1988-1994) and earlier national surveys were examined. RESULTS: Mean energy intake changed little from the 1970s to 1988-1994 except for an increase among adolescent females. Over the same time period, the mean percentage of energy from total and saturated fat decreased, but remained above recommendations, with overall means of 33.5% of energy from fat and 12.2% of energy from saturated fat. In 1988-1994, approximately 1 in 4 youths met the recommendations for intakes of fat and saturated fat and 3 in 4 met the recommendation for cholesterol intake. Beverages contributed 20-24% of energy across all ages and soft drinks provided 8% of energy in adolescents. Except for adolescent girls, beverage energy contributions were generally higher among overweight than nonoverweight youths; soft drink energy contribution was higher among overweight youths than among nonoverweight youths for all groups. CONCLUSIONS: The lack of evidence of a general increase in energy intake among youths despite an increase in the prevalence of overweight suggests that physical inactivity is a major public health challenge in this age group. Efforts to increase physical activity and decrease nonnutritive sources of energy may be important approaches to counter the rise in overweight prevalence.

Zinc intake of the U.S. population: findings from the third National Health and Nutrition Examination Survey, 1988-1994.

National survey data for 29,103 examinees in the third National Health and Nutrition Examination Survey were used to estimate mean and percentile distributions of dietary and total zinc intakes based on 24-h dietary recalls and vitamin/supplement use. Mean daily total intakes ranged from 5.5 mg in non-breast-feeding infants to 13 mg in adults and were higher in adolescent and adult males than in females (P <0.01). Mean total zinc intakes (22 mg) were approximately 10 mg higher in pregnant and lactating females than in nonpregnant, nonlactating females of the same age. Mean total zinc intakes were 0. 7 mg higher in adolescents (11.1 mg) and 2.5-3.5 mg higher in adults (13 mg) compared with mean dietary intakes, indicating the average contribution of supplements to total zinc intake. Mean total zinc intakes were significantly higher in non-Hispanic whites than in non-Hispanic blacks (P<0.01) and Mexican Americans (P<0.01) for men and women aged 51-70 y and > or =71 y due to higher zinc supplement use. The prevalence of zinc-containing supplements use ranged from 0. 1% in infants to 20.5% in adults. "Adequate" zinc intake in this survey population was 55.6% based on total intakes of >77% of the 1989 recommended dietary allowance. Young children aged 1-3 y, adolescent females aged 12-19 y and persons aged > or =71 y were at the greatest risk of inadequate zinc intakes.

The effectiveness of a short form of the Household Food Security Scale.

OBJECTIVES: On the basis of an 18-item Household Food Security Scale, a short form was developed to assess financially based food insecurity and hunger in surveys of households with and without children. METHODS: To maximize the probability that households would be correctly classified with respect to food insecurity and hunger, 6 items from the full scale were selected on the basis of April 1995 Current Population Survey data. RESULTS: The short form classified 97.7% of households correctly and underestimated the prevalence of overall food insecurity and of hunger by 0.3 percentage points. CONCLUSIONS: The short form of the Household Food Security Scale is a brief but potentially useful tool for national surveys and some state/local applications.

Food insufficiency exists in the United States: results from the third National Health and Nutrition Examination Survey (NHANES III).

OBJECTIVES: The purpose of this study was to estimate the prevalence of food insufficiency in the United States and to examine sociodemographic characteristics related to food insufficiency. METHODS: Data were analyzed from the third National Health and Nutrition Examination Survey, a cross-sectional representative sample of the civilian noninstitutionalized population living in households. Individuals were classified as "food insufficient" if a family respondent reported that the family sometimes or often did not get enough food to eat. RESULTS: From 1988 through 1994, the overall prevalence of food insufficiency was 4.1% and was primarily related to poverty status. In the low-income population, food insufficiency was positively associated with being Mexican American, being under the age of 60, having a family head who had not completed high school, participating in the Food Stamp Program, and not having health insurance. It was not related to family type or employment status of the family head. Over half of food-insufficient individuals lived in employed families. CONCLUSIONS: Food insufficiency is not limited to very low-income persons, specific racial/ethnic groups, family types, or the unemployed. Understanding food insufficiency is critical to formulating nutrition programs and policies.

Distributions and trends of serum lipid levels among United States children and adolescents ages 4-19 years: data from the Third National Health and Nutrition Examination Survey.

BACKGROUND: Atherosclerosis begins in childhood and progresses into adulthood. The reduction of cardiovascular risk factors, such as elevated serum total cholesterol and low-density lipoprotein cholesterol (LDL-C) levels, in childhood may reduce cardiovascular morbidity and mortality in adulthood. Lipid distributions among children and adolescents were examined using the most recent nationally representative data. METHODS: Data from 7,499 examinees in NHANES III (1988-1994) were used to estimate mean and percentile distributions of serum total cholesterol, LDL-C, high-density lipoprotein cholesterol (HDL-C), and triglycerides in children and adolescents aged 4 to 19 years. The estimates were analyzed by age, sex, and race/ethnic groups. Trends in mean total cholesterol were examined for 12- to 17-year-olds using data from NHES III (1966-1970), NHANES I (1971-1974), and NHANES III (1988-1994). RESULTS: For children and adolescents 4 to 19 years of age, the 95th percentile for serum total cholesterol was 216 mg/dL and the 75th percentile was 181 mg/dL. Mean age-specific total cholesterol levels peaked at 171 mg/dL at 9-11 years of age and fell thereafter. Females had significantly higher mean total cholesterol and LDL-C levels than did males (P < 0.005). Non-Hispanic black children and adolescents had significantly higher mean total cholesterol, LDL-C, and HDL-C levels compared to non-Hispanic white and Mexican American children and adolescents. The mean total cholesterol level among 12- to 17-year-olds decreased by 7 mg/dL from 1966-1970 to 1988-1994 and is consistent with, but less than, observed trends in adults. Black females have experienced the smallest decline between surveys. CONCLUSIONS: The findings provide a picture of the lipid distribution among U.S. children and adolescents and indicate that, like adults, adolescents have experienced a fall in total cholesterol levels. Total cholesterol levels in U.S. adolescents declined from the late 1960s to the early 1990s by an average of 7 mg/dL. This information is useful for planning programs targeting the prevention of cardiovascular disease beginning with the development of healthy lifestyles in childhood.

Consistency between US dietary fat intake and serum total cholesterol concentrations: the National Health and Nutrition Examination Surveys.

The National Health and Nutrition Examination Surveys (NHANESs) are conducted periodically to assess the health and nutritional status of the US population by means of standardized interviews and physical examinations. Since the early 1970s there have been three national cross-sectional surveys: NHANES I, 1971-1974; NHANES II, 1976-1980; and NHANES III, phase 1, 1988-1991. During the 18 y between the midpoint of NHANES I (1972) and the midpoint of phase 1 of NHANES III (1990), the age-adjusted mean percentage of energy from fat declined from 36.4% to 34.1% for adults aged 20-74 y. Trend data are shown for dietary fat and cholesterol as well as for serum cholesterol from NHANES I (1971-1975) to NHANES III (1988-1991) by age, sex, and race-ethnicity. The results document a decline in dietary fat, saturated fat, dietary cholesterol, and serum cholesterol. The observed changes reflect those that are predicted by the classic Keys and Hegsted formulas. Changes in reported intake are matched by similar shifts in the food supply for sources of these nutrients. These changes suggest that the Healthy People 2000 goal of reducing the mean serum cholesterol concentration of US adults to < or = 200 mg/dL (5.17 mmol/L) is attainable. The changes in diet are promising, yet we are challenged to achieve greater reductions in the intake of total fat and saturated fatty acids.

Cardiovascular health risks related to overweight.

Cross-sectional surveys of the civilian noninstitutionalized population of the United States, including in-home interviews and clinical examinations, were employed to examine trends in consumption of energy and fat, prevalence of overweight in the population, the association of overweight with levels of blood pressure and blood cholesterol, and the prevalence of high blood pressure and high blood cholesterol among the overweight compared with the nonoverweight. Data from participants 20 years of age and older are reported. Study results suggest that total mean energy intake, although generally accepted to be underreported in dietary surveys, may have increased. Total fat and saturated fat intake as a percent of energy decreased, but remained above recommended levels. Overweight has increased in the population, despite decreases in the prevalence of high blood pressure and high blood cholesterol levels. Increased levels of overweight, reported as body mass index, are associated with increased cardiovascular risk factors of high blood pressure and high blood cholesterol. These data suggest the need for health care practitioners to emphasize the requirement for energy balance (or weight loss if overweight, ie, not at a "healthy weight"). A focus on fat intake alone without emphasis on energy balance is inadequate for achieving and maintaining recommended weight.

Prevalence of overweight among preschool children in the United States, 1971 through 1994.

OBJECTIVE: To examine the prevalence of overweight among US preschool children 2 months through 5 years of age between the years 1971 through 1974 and 1988 through 1994. DESIGN: Nationally representative cross-sectional surveys with a physical examination, including measurement of stature, length, and weight. Between 1200 and 7500 children younger than 6 years were examined in each of four different surveys during 1971 through 1974 (first National Health and Nutrition Examination Survey [NHANES I]), 1976 through 1980 (NHANES II), 1982 through 1984 (Hispanic Health and Nutrition Examination Survey), and 1988 through 1994 (NHANES III). RESULTS: The prevalence of overweight increased among some sex and age groups of preschool children between 1971 through 1974 and 1988 through 1994. More than 10% of 4- and 5-year-old girls were overweight in 1988 through 1994 compared with 5.8% in 1971 through 1974. However, there was no change during this period in the prevalence of overweight among 1- and 2- to 3-year-old children. During 1988 through 1994, the prevalence of overweight among children 2 months through 5 years of age was consistently higher in girls than boys. Mexican-American children had a higher prevalence of overweight than non-Hispanic black and non-Hispanic white children. These results parallel what has been reported for older children and adults in the United States. CONCLUSION: These results show that in the last 20 years the prevalence of overweight has increased among 4- and 5-year-old children but not among younger children. These findings suggest that efforts to prevent overweight, including encouragement of physical activity and improved diets, should begin in early childhood.

Dietary methods research in the third National Health and Nutrition Examination Survey: underreporting of energy intake.

Assessment of diet is a critical component of the third National Health and Nutrition Examination Survey (NHANES III), which was designed to describe the health and nutritional status of the US population. We analyzed data collected with the primary dietary assessment instrument used in NHANES III, the 24-h recall, for 7769 nonpregnant adults aged > or = 20 y to investigate underreporting of total energy intake. Underreporting was addressed by computing a ratio of energy intake (EI) to estimated basal metabolic rate (BMRest). EI:BMRest was 1.47 for men and 1.26 for nonpregnant women; a population level of 1.55 is expected for a sedentary population. About 18% of the men and 28% of the women were classified as underreporters. Underreporting of energy intake was highest in women and persons who were older, overweight, or trying to lose weight. Underreporting varied according to smoking status, level of education, physical activity, and the day of the week the 24-h recall covered. Additionally, underreporting was associated with diets lower in fat (P < 0.01) and alcohol (P < 0.01 in women) when expressed as a percentage of total energy intake.

Relation of changes in dietary lipids and weight, trial years 1-6, to changes in blood lipids in the special intervention and usual care groups in the Multiple Risk Factor Intervention Trial.

For men in the special intervention (SI) group of the Multiple Risk Factor Intervention Trial, the average decrease in serum total cholesterol was 16.9 mg/dL (6.7%); for men in the usual care (UC) group, the average decrease was 9.7 mg/dL (3.8%). The difference between the two groups for plasma total cholesterol was 6.2 mg/dL. Plasma low-density-lipoprotein (LDL) cholesterol decreased 10.6 mg/dL (6.6%) in SI men and 5.4 mg/dL (3.4%) in UC men. Mean weight losses were 3.0 lb (1.36 kg) and 0.1 lb (0.05 kg) for SI and UC men, respectively. Change in blood total cholesterol was directly related to baseline concentration; for men with serum total cholesterol > or = 220 mg/dL, those in the SI group decreased their total cholesterol by 7.8% (design goal: 10%) and those in the UC group by 4.8% (expected: 0%). Change in dietary lipid intake (summarized by the Keys score) for SI men was significantly related to changes in blood total cholesterol, LDL cholesterol, and triglyceride, but not to change in high-density-lipoprotein (HDL) cholesterol. Controlled for weight change, coefficients for Keys score change were smaller but remained significantly related to each blood lipid except HDL cholesterol. Weight loss was associated with favorable effects on all blood lipids. Influences of change in diet and weight on blood lipids were quantitatively less for hypertensive men for serum total cholesterol, HDL cholesterol, and triglyceride than for nonhypertensive men. Nonsmokers had greater decreases than smokers in blood total cholesterol, LDL cholesterol, and triglyceride.

Total energy intake of the US population: the third National Health and Nutrition Examination Survey, 1988-1991.

The third National Health and Nutrition Examination Survey (NHANES III) was conducted to assess the health and nutritional status of the US population. As part of the nutritional status assessment, reliable 24-h dietary recalls were collected for 14,801 examined persons. Mean (+/- SEM) energy intakes are reported for persons aged > or = 2 mo by age, sex, and race-ethnicity. Males had higher mean energy intakes than did females. Energy intakes peaked during late adolescence and young adulthood and declined thereafter. Energy intake patterns were similar among non-Hispanic whites, non-Hispanic blacks, and Mexican Americans. Underreporting was addressed by computing a ratio of energy intake (EI) to estimated basal metabolic rate (BMRest). This ratio (EI:BMRest) was 1.47 for adult males and 1.26 for nonpregnant adult females. Overweight adults had a lower mean EI:BMRest (1.09 in females and 1.28 in males). Underreporting in food consumption surveys remains problematic among females and overweight persons.

Dietary intake of vitamins, minerals, and fiber of persons ages 2 months and over in the United States: Third National Health and Nutrition Examination Survey, Phase 1, 1988-91.

Intervention strategies aimed at reducing the prevalence of nutrition-related diseases, including designing nutrition policies and nutrition education and assistance programs, require effective monitoring of what Americans are eating. Nutrient reference data from the third National Health and Nutrition Examination Survey provide essential information to achieve these goals. Mean and median iron intakes were adequate in males of all race-ethnic groups but were generally low in females and young children. Mean and median calcium intakes were also higher in males than in females and were lower than recommendations in adolescents and in women of all ages. Mean sodium intakes for all age, sex, and race-ethnic groups exceeded the minimum requirements of healthy persons and were higher in non-Hispanic black children and adolescents than in non-Hispanic white and Mexican American children and adolescents. Mean fiber intakes also did not meet recommendations in most subgroups and were higher in Mexican American adults followed by non-Hispanic white adults and non-Hispanic black adults. Further research is planned to compare the food sources of energy and nutrients consumed by different population groups in NHANES III to similar results from earlier nation surveys. NHANES III, Phase 2 (1991-94) recalls were collected using the same dietary method as those collected in Phase 1 (1988-91), and other analyses will compare findings from both phases of NHANES III.

Assessment of the US diet in national nutrition surveys: national collaborative efforts and NHANES.

The National Nutrition Monitoring and Related Research Program includes conducting national surveys to estimate the dietary intake and nutritional status of the US population. As part of this program, a 10-y comprehensive plan has been developed to strengthen nutrition-monitoring efforts in the United States. Emphasis is placed on improving coordination and comparability among data collection methods across federal agencies and on conducting relevant research. Current collaborative efforts between the US Departments of Health and Human Services (DHHS) and Agriculture (USDA) include coordinating the national food-consumption surveys in the areas of planning population coverage, by using comparable dietary intake methods, and targeting research toward improving dietary methods. The National Health and Nutrition Examination Survey (NHANES) contributes population data on diet, nutritional status, and health outcomes to the Nutrition Monitoring Program. The third NHANES (1988-1994) includes 40,000 noninstitutionalized people aged > or = 2 mo and oversamples blacks, Mexican Americans, children, and elderly people and uses an automated 24-h recall as the primary dietary instrument. Assessing dietary intake in heterogeneous populations in national surveys poses many methodologic, statistical, and interpretive issues and highlights the need for specific research to improve dietary assessment methods.

Declining serum total cholesterol levels among US adults. The National Health and Nutrition Examination Surveys.

OBJECTIVE: To examine the secular trend in serum total cholesterol levels of the US adult population. DESIGN: Nationally representative cross-sectional surveys with both an in person interview and a medical examination that included the measurement of blood lipid levels. SETTING/PARTICIPANTS: Between 6000 and 13,000 adults aged 20 through 74 years examined in each of four separate national surveys during 1960 through 1962, 1971 through 1974, 1976 through 1980, and 1988 through 1991. RESULTS: Mean serum total cholesterol levels in US adults aged 20 through 74 years have consistently declined over the time period 1960 through 1991. More than half of the decline occurred during the time period 1976 through 1991. This decline occurred across the entire distribution of serum cholesterol levels and in all age-sex groups. High-density lipoprotein cholesterol and very low-density lipoprotein cholesterol levels have not changed, suggesting that the decline in total cholesterol levels is due to a decline in low-density lipoprotein cholesterol levels. CONCLUSIONS: These results document a continuing and substantial decline in serum cholesterol levels among US adults. They suggest that public health programs, designed to reduce cholesterol levels, are proving successful. The observed downward trend in serum cholesterol levels has coincided with a continuing decline in coronary heart disease mortality. These observations suggest that the Healthy People 2000 goal of reducing the mean serum cholesterol level of US adults to no more than 200 mg/dL (5.17 mmol/L) is attainable.

Prevalence of high blood cholesterol among US adults. An update based on guidelines from the second report of the National Cholesterol Education Program Adult Treatment Panel.

OBJECTIVE: To estimate the current levels and trends in the proportion of US adults with high blood cholesterol based on guidelines from the second report of the National Cholesterol Education Program (NCEP) Adult Treatment Panel (ATP II). DESIGN: Nationally representative cross-sectional surveys. SETTING/PARTICIPANTS: Data for 7775 participants 20 years of age and older from phase 1 of the third National Health and Nutrition Examination Survey (NHANES III) (data collected from 1988 through 1991) and for 9797 participants 20 through 74 years of age from NHANES II (data collected from 1976 through 1980) were used. RESULTS: From the data collection period in NHANES II (1976 through 1980) to the period in NHANES III (1988 through 1991), the proportion of adults with high blood cholesterol levels (> or = 240 mg/dL [6.21 mmol bd) fell from 26% to 20%, while the proportion with desirable levels (< 200 mg/dL [5.17 mmol/L]) rose from 44% to 49%. Currently, using the ATP II guidelines and NHANES III data, 40% of all adults 20 years of age and older would require fasting lipoprotein analysis; and 29% of all adults would be candidates for dietary therapy (as compared with 36%, using NHANES II data). Based on 1990 population data, it is estimated that approximately 52 million Americans 20 years of age and older would be candidates for dietary therapy. Assuming that dietary intervention would reduce low-density lipoprotein (LDL) cholesterol levels by 10%, as many as 7% of all adult Americans (approximately 12.7 million) might be candidates for cholesterol-lowering drugs. This estimate reflects approximately 4 million adults with established coronary heart disease, of whom half are aged 65 years and older, and up to 8.7 million adults without established coronary heart disease, of whom up to 3.1 million are aged 65 years and older. CONCLUSIONS: Substantial progress has been made in reducing the prevalence of high blood cholesterol; yet a large proportion of all adults, approximately 29%, require dietary intervention for high blood cholesterol.

The National Health and Nutrition Examination Survey III: describing the health and nutritional status of older Americans.

The National Health and Nutrition Examination III will provide important data for examination of the health and nutritional status of persons in the U.S. Innovations in the study, particularly the inclusion of persons over age 74 and the focus of the survey on the major chronic diseases of old age, will enhance the value for older persons. Response rates for phase 1 (1988-1991) show that about 80% of all older subjects agreed to the interview; examination rates declined with age, but the use of a home examination increased the response rate for those aged 75 or older by about 9% to 67% for men and about 62% for women. Analytic plans include examination of the effect of nutrition on health, as well as the effect of health status on the distribution of nutritional risk factors in old age.

Issues in the long-term evaluation of diet in longitudinal studies.

Longitudinal studies are very useful for studying diet/disease relationships. The fundamental components of a longitudinal study are that: 1) data are collected for two or more distinct time periods; 2) the subjects are the same or comparable from one time period to the next; and 3) data are compared between or among time periods in the analysis. A longitudinal study is often assumed to be synonymous with a cohort study, but there are at least four possible definitions for a longitudinal study. While focusing on cohort studies, the paper describes the nature of longitudinal studies, including a discussion of how the different definitions differ from a cohort study and a set of important assumptions necessary to cohort studies. It also highlights some of the major issues associated with such studies, including the selection of a dietary survey methodology; data collection issues in multicultural, multilingual societies; the importance of nutrient databases; measurement error and misclassification in nutrient intake and energy adjustment.