Choose a diet that is low in saturated fat and cholesterol and moderate in total fat: subtle changes to a familiar message.

"Choose a diet that is low in saturated fat and cholesterol and moderate in total fat," issued in Nutrition and Your Health: Dietary Guidelines for Americans in the year 2000, has an interesting and lengthy history. The first guideline, for which there was extensive scientific data to show that dietary excess increased chronic disease risk, prompted much scientific discussion and debate when implemented as dietary guidance. Three major changes in the guideline are noted since it was issued in 1980, i.e., numerical goals for dietary fats; the applicability of recommended fat intakes for all individuals > or =2 y old; and rewording to emphasize reducing saturated fat and cholesterol intakes. The shift in emphasis includes the terminology moderate fat, which replaces the phrasing low fat. National data about the food supply, the population's dietary intake, knowledge, attitudes and behaviors, and nutritional status indicators (e.g., serum cholesterol levels) related to dietary fats help to monitor nutrition and health in the population. Experts consider that national data, although not without limitations, are sufficient to conclude that U.S. intakes of fats, as a proportion of energy, have decreased. The lower intakes of saturated fat and cholesterol are consistent with decreases in blood cholesterol levels and lower rates of coronary mortality over the past 30 years. Strategies are needed and some are suggested, to further encourage the population to achieve a dietary pattern that is low in saturated fat and cholesterol and moderate in total fat. Other suggestions are offered to improve national nutrition monitoring and surveillance related to the guideline.

Choose and prepare foods with less salt: dietary advice for all Americans.

The Nutrition and Your Health: Dietary Guidelines for Americans have included dietary guidance on salt and sodium since they were first released in 1980. This paper briefly reviews the impetus for including sodium guidelines, changes in them over time and factors influencing these changes. Although guidance appears to have changed little over the five editions, differences in wording reflect changes in knowledge of the link between sodium and blood pressure, a shift in public health policy toward prevention and increased consumption of processed and prepared foods. We examine methods to monitor sodium intake and assess whether Americans are following these guidelines. Available data indicate that American adolescents and adults are consuming more sodium than recommended and are unable to judge whether the amount of sodium in their diet is appropriate. Although Americans avoid adding salt to food at the table, their efforts may have little effect given that the majority of salt consumed is added during commercial processing and preparation. Thus, changes to the Dietary Guidelines that emphasize the major sources of sodium in U.S. diets and advice to "choose and prepare foods with less salt" may help all Americans meet recommended sodium intake levels in the future.

Body mass index and the prevalence of hypertension and dyslipidemia.

OBJECTIVE: To describe and evaluate relationships between body mass index (BMI) and blood pressure, cholesterol, high-density lipoprotein-cholesterol (HDL-C), and hypertension and dyslipidemia. RESEARCH METHODS AND PROCEDURES: A national survey of adults in the United States that included measurement of height, weight, blood pressure, and lipids (National Health and Nutrition Examination Survey III 1988-1994). Crude age-adjusted, age-specific means and proportions, and multivariate odds ratios that quantify the association between hypertension or dyslipidemia and BMI, controlling for race/ethnicity, education, and smoking habits are presented. RESULTS: More than one-half of the adult population is overweight (BMI of 25 to 29.9) or obese (BMI of > or =30). The prevalence of high blood pressure and mean levels of systolic and diastolic blood pressure increased as BMI increased at ages younger than 60 years. The prevalence of high blood cholesterol and mean levels of cholesterol were higher at BMI levels over 25 rather than below 25 but did not increase consistently with increasing BMI above 25. Rates of low HDL-C increased and mean levels of HDL-C decreased as levels of BMI increased. The associations of BMI with high blood pressure and abnormal lipids were statistically significant after controlling for age, race or ethnicity, education, and smoking; odds ratios were highest at ages 20 to 39 but most trends were apparent at older ages. Within BMI categories, hypertension was more prevalent and HDL-C levels were higher in black than white or Mexican American men and women. DISCUSSION: These data quantify the strong associations of BMI with hypertension and abnormal lipids. They are consistent with the national emphasis on prevention and control of overweight and obesity and indicate that blood pressure and cholesterol measurement and control are especially important for overweight and obese people.

Food and nutrient exposures: what to consider when evaluating epidemiologic evidence.

Nutritional epidemiology is the science concerned with conducting research into the relation between diet and disease risk. The public has a great deal of interest in this issue. Much of that interest, however, is fueled by the publication of sensationalized, startling, and often contradictory health messages. Unfortunately, there is a great deal of confusion in both the scientific press and the public or lay press about the nature of nutritional epidemiology, its strengths, and its limitations. The purpose of this article is to discuss these strengths and limitations. It is hoped that clarification of these issues can help lead to a resolution of the research community's and lay public's misunderstandings about nutritional epidemiology research.

Dietary fat consumption and health.

Dietary Guidelines have emerged over the past 30 years recommending that Americans limit their consumption of total fat and saturated fat as one way to reduce the risk of a range of chronic diseases. However, a low-fat diet is not a no-fat diet. Dietary fat clearly serves a number of essential functions. For example, maternal energy deficiency, possible exacerbated by very low-fat intakes (< 15% of energy), is one key determinant in the etiology of low birth weight. The debate continues over recommendations for limiting total fat and saturated fatty acid intake in children. Recent evidence indicates that diets with adequate energy providing less than 30% of energy from fat are sufficient to promote normal growth and normal sexual maturation. More attention needs to be devoted to the effect of dietary fat reduction on the nutrient density of children's diets. The association between dietary fat and CHD has been extensively studied. Diets high in saturated fatty acids and trans fatty acids increase LDL cholesterol levels, and in turn, the risk of heart disease. The relationship between high-carbohydrate/low-fat diets and CHD is more ambiguous because high-carbohydrate diets induce dyslipidemia in certain individuals. Obesity among adults and children is now of epidemic proportions in the United States. High-fat diets leading to excessive energy intakes are strongly linked to the increasing obesity in the United States. However, the prevalence of obesity has increased during the same time period that dietary fat intake (both in absolute terms and as a percentage of total dietary energy) has decreased. These trends suggest that a concomitant decrease in total dietary energy and modifications of other lifestyle factors, such as physical activity, also need to be emphasized. Obesity is also an independent risk factor for the development of diabetes. The current availability of fat-modified foods offers the potential for dietary fat reduction and treatment of the comorbidities associated with diabetes. However, to date, few studies have documented the effectiveness of fat-modified foods as part of a weight loss regimen or in reduction in CHD risks among individuals with diabetes mellitus. The association between total dietary fat and cancer is still under debate. While there is some evidence demonstrating associations between dietary fat intake and cancers of the breast, prostate, and colon, there are serious methodologic issues, including the difficulty in differentiating the effects of dietary fat independent of total energy intake. Reported total fat and saturated fatty acid intakes as a percentage of total energy have been declining over the past 30 years in the United States. Despite this encouraging trend, the majority of individuals--regardless of age--do not report consuming a diet that meets the levels of fat and saturated fatty acids recommended by the Dietary Guidelines for Americans. On a relative basis, saturated fat intake has gone down less than has total fat intake. Individuals of all ages who report consuming a diet with < or = 30% of energy from fat consistently have lower energy intakes. Given the increasing rates of obesity in the United States at an earlier and earlier age, dietary fat reduction may be an effective part of an overall strategy to balance energy consumption with energy needs. In each of the age/gender groups reporting consumption of < or = 30% of energy from fat and less than 10% of energy from saturated fatty acids, fat-modified foods play a more important role in their diets than for people who are consuming higher levels of fat and saturated fat. The data are clear than fat-modified foods make a more significant contribution to diets of consumers with low-fat intakes. While one cannot argue cause and effect from the results presented, the patterns of fat-modified foods/low-fat intakes are consistent. The focus on overall diet quality is often lost in the national obsession with lowering fat inta

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.

Child health and nutrition: obesity and high blood cholesterol.

BACKGROUND. The epidemiology of obesity and high blood cholesterol in children is discussed, along with strategies for the prevention of these two disorders and mention of some nutrition and child health research and education programs supported by the National Heart, Lung, and Blood Institute (NHLBI). CONCLUSIONS. Available data confirm that both obesity and high blood cholesterol levels in U.S. children are higher than optimal and that the benefit of reducing the prevalence of these conditions in childhood will be realized in adulthood. Current NHLBI-supported research and education activities focus on unanswered questions about the childhood predictors of transition to the obese state, the feasibility, efficacy, and safety of long-term dietary intervention in children, and the effects of school-based intervention that include classroom curriculum and school environmental changes related to food intake, physical activity, and tobacco use and dissemination of materials that promote nutrition and cardiovascular health in children and adolescents.

Health promotion roles of the federal government and food industry in nutrition and blood pressure.

Some principal activities of government that pertain to nutrition and blood pressure are education, information, dietary guidance, food regulatory practices, health and nutrition monitoring, biomedical research and training, and legislation. The food industry, in turn, influences the marketplace and food consumption by its response to government activities and policies. Dietary guidance recommendations call for moderation of dietary intake, improved nutrition, and greater availability in food choices in the marketplace that are consistent with dietary recommendations to reduce chronic disease risk. Health and nutrition monitoring allows measurement of the effectiveness of moderating dietary intake and controlling hypertension. Adequate support of education, nutrition and health monitoring, and biomedical research and training is necessary to control and prevent hypertension. Cooperation between government and industry can contribute to the decline in cardiovascular disease, which in 1987 cost this nation in excess of $135 billion.

The National Cholesterol Education Program: implications for dietetic practitioners from the Adult Treatment Panel recommendations.

The National Cholesterol Education Program (NCEP) was initiated to contribute to the prevention of illness and death from coronary heart disease by reducing the prevalence of high blood cholesterol. The report of an expert panel of this program provides guidelines for the treatment of high blood cholesterol in adults 20 years of age and over. Dietary therapy is the primary treatment. The goal of the recommended dietary therapy is to lower the LDL-cholesterol concentration, although measurement of total blood cholesterol can be used to monitor the response to diet. Dietary modification involves a progressive decrease in intake of saturated fatty acids and cholesterol. The Step-One Diet calls for an intake of total fat less than 30% of calories, saturated fatty acids less than 10% of calories, and cholesterol less than 300 mg/day. If the desired decrease in LDL-cholesterol is not achieved with that dietary change, then the Step-Two Diet is begun. It requires a reduction in saturated fatty acids to less than 7% of calories and cholesterol to less than 200 mg/day. This article provides background information on the organization and objectives of the NCEP and focuses on the recommendations of the Adult Treatment Panel (ATP), e.g., classification of risk for developing coronary heart disease based on total and low-density-lipoprotein cholesterol levels and recommendations for treatment of patients with high blood cholesterol. The emphasis of the discussion is on dietary treatment. The implications of the recommendations for the dietetic practitioner are discussed. These include an expanded leadership role to meet the education needs of health professionals and patients.

Nutrition education at the point of purchase: the foods for health project evaluated.

Foods for Health, a nutrition education and research program sponsored by the National Heart, Lung, and Blood Institute and Giant Food, Inc., was designed to demonstrate the feasibility of cardiovascular nutrition education at the point of purchase, specifically, in the supermarket. To evaluate the program's effectiveness, measures of consumer awareness, knowledge, and food purchases were determined before, during, and after the campaign. The program was conducted in the Washington, D.C., area, with Baltimore, Maryland, area stores serving as controls. At the conclusion of the campaign, Washington shoppers showed a significant increase in knowledge scores, while these scores decreased in the Baltimore area. The gain in correct knowledge scores for Washington shoppers compared with Baltimore shoppers was 9% for food fat and cholesterol content and 11% for the relationship between dietary fat and blood cholesterols levels. The food sales data indicate no apparent differences attributable to the intervention. Issues that might account for the lack of a significant change in food purchases, such as cost and the markets' individual sales promotion campaigns, are discussed, and recommendations for the design of future projects are made.

NIH Consensus Development Conference on lowering blood cholesterol to prevent heart disease: implications for dietitians.

Coronary heart disease is responsible for more than 550,000 deaths in the United States each year. It is estimated that coronary heart disease costs the United States more than $60 billion a year in direct and indirect costs. Issues related to the exact relationship between blood cholesterol and heart attacks and the steps that should be taken to diagnose and treat elevated blood cholesterol levels were considered by a consensus development conference. The conclusions of the consensus panel, their recommendations, and implications for the dietetic profession are considered.

The effects of low cholesterol, high polyunsaturated fat, and low fat diets on plasma lipid and lipoprotein cholesterol levels in normal and hypercholesterolemic subjects.

The effects of various cholesterol-lowering diets on plasma lipid and lipoprotein cholesterol levels were assessed in normal and hypercholesterolemic subjects. The base-line diet was an ad libitum hospital diet of normal composition. Diet A was a 20% protein, 40% carbohydrate, 40% fat, polyunsaturated:saturated fat ratio 0.1 to 0.3, 250 to 300 mg cholesterol diet, diet B was identical to diet A except that the polyunsaturated/saturated fat ratio was 1.8 to 2.2, and diet C was a 20% protein, 80% carbohydrate, very low fat (5 to 10 g), polyunsaturated/saturated fat ratio 0.1 to 0.3, 150 to 200 mg cholesterol diet. Diet A (low cholesterol) caused mean reductions in plasma, low-density lipoprotein (LDL), and high-density lipoprotein (HDL) cholesterol of 5.9, 5.6, and 6.3%, respectively, in 11 normal subjects. Diet B (low cholesterol, high polyunsaturated fat) caused significant decreases in plasma cholesterol, LDL cholesterol and HDL cholesterol of 17.0, 16.2, and 17.4%, respectively, in 12 normal subjects; and reductions of 11.0, 10.8, and 17.1%, respectively, in 19 hypercholesterolemic subjects. Diet C (low cholesterol, very low fat) produced significant mean decreases in plasma, LDL, and HDL cholesterol of 26.7, 29.9, and 27.9%, respectively, in 11 normal subjects, and in nine hypercholesterolemic patients of 22.6, 27.2, and 28.6%, respectively. The reductions in plasma cholesterol caused by these diets were therefore due to decreases in both LDL and HDL cholesterol with no significant changes in the LDL cholesterol:HDL cholesterol ratio.