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Using an epidemiologic model of the interactions between environmental agents and human hosts to explain obesity, we explored food, medications, physical inactivity, toxins, and viruses as environmental agents that interact with a genetically programmed host to disturb energy balance and cause obesity. Large portion sizes, high fat intakes, easy access to calorically sweetened beverages, and lack of any need to be physically active all play a role in the toxic environment that leads to obesity. The genetic and physiologic responses of a host determine whether or not this toxic environment will produce obesity. Reversing the current trends of obesity requires a new look at the limits of the energy balance concept, and a better understanding of how environmental factors acutely and chronically change the responses of susceptible hosts. J Am Diet Assoc. 2005;105:S17-S23.

Objective To collect and evaluate food intake data from a culturally diverse population and compare with national survey data. Design The Foods Of Our Delta Study was a baseline, cross-sectional survey that utilized random-digit dialing methodology to identify the sample. Food intake was obtained from a 24-hour dietary recall administered by computer-assisted telephone interview using the multiple-pass method Subjects/Setting One thousand seven hundred fifty-one adults and 485 children in the Lower Mississippi Delta (Delta) of Louisiana, Arkansas, and Mississippi. Statistical Analyses Performed Comparisons of subsets within the Delta were made using weighted t tests. Comparisons of the Delta with the overall US population from the US Department of Agriculture Continuing Survey of Food Intakes by Individuals and with the Dietary Reference Intakes were made using independent sample z tests of weighted estimates. Results Energy intake did not differ between the Delta and the US populations. Intakes of protein were lower, fat higher, and certain micronutrients lower in Delta adults than in US adults. Delta adults had a 20% lower intake of fruits and vegetables than the US adults and generally poorer adherence to recommendations of the Food Guide Pyramid. African American Delta adults generally consumed less-optimal diets than white Delta adults. Delta children had diets similar to children of the Continuing Survey of Food Intakes by Individuals sample population, but lower intakes were noted for vitamins A, C, riboflavin, and B-6, and for calcium and iron. Applications/Conclusions Data such as these will help drive intervention development in this rural region and perhaps set the stage for research in similarly impoverished areas. J Am Diet Assoc. 2004;104:199-207.

The Metabolic Syndrome encompasses a set of laboratory and physical findings, including central adiposity, insulin resistance, hypertension, high triglycerides, and low HDL-cholesterol and several abnormalities in clotting and inflammatory markers. Using the definition provided by the Adult Treatment Panel III of the National Cholesterol Education Program, 24% of adult Americans have the Metabolic Syndrome. Central location of fat and release of fatty acids and cytokines from enlarged fat cells located in the intra-abdominal fat tissue provide the major agents that incite this syndrome. From a practical point of view, identifying dietary and lifestyle factors, including low levels of physical activity, are important in designing a diet and exercise program that can help individuals with the Metabolic Syndrome to reduce the associated detrimental health consequences. J Am Diet Assoc. 2004;104:86-89.

The aim of this paper is to identify major food group sources of several essential nutrients in the two dietary patterns used in the DASH-Sodium trial: a control diet and the DASH dietary pattern. The DASH-Sodium trial was a multicenter, randomized, controlled-feeding trial comparing the effects of three levels of sodium and two dietary patterns on blood pressure. Nutrient contents of all the menus for both the control and the DASH diets were analyzed and examined for their dietary sources from 13 food groups. Contributions of all foods within each food group to each nutrient were averaged then weighted to reflect the actual distribution of energy levels in the study. Nutrient contents across the three sodium levels are very similar within each diet. Refined grains and whole grains are the major energy sources for the control and the DASH diet, providing 35% and 23% to the total intake, respectively. Nutrient-dense whole grains contributed greatly, ranging from 11% to 46%, to the higher intakes of protein, fi ber, calcium, magnesium, potassium, zinc, and folate in the DASH diet. Vegetables, in addition to being a good source for fiber, vitamins A, C, E, and folate, also contributed an average of 15% to the intakes of magnesium, potassium, and calcium in the DASH diet. Differences in nutrient contents between the control and the DASH diets were accomplished by varying the selection of food items (eg, refined grains vs whole grains) and quantities of certain food groups (eg, less red meats and higher amounts of fruits and vegetables). The DASH dietary pattern recommends four to five servings of fruits; four to five servings of vegetables; two to three servings of low-fat dairy products; seven to eight servings of grain products (preferably whole grains); two or less servings of meats, poultry, and fish per day; and four to five servings of nuts, seeds, and legumes per week for a 2,000 kcal diet. Each of these food groups contributes critical nutrients across various sodium levels. It is important to emphasize all fo od groups when trying to follow this proven dietary pattern. J Am Diet Assoc. 2003;103:488-496., The DASH dietary pattern, which emphasizes fruits, vegetables, and low-fat dairy products and is reduced in saturated and total fats and in cholesterol, has been shown to lower blood pressure [...]

Dietary creatine (Cr) supplementation has been shown to enhance muscular strength and endurance. This study determined the effects of Cr supplementation on performance of military training tasks. Two groups (Cr and placebo [P1]) of 13 male soldiers each performed 3 consecutive military obstacle course runs (~3 minutes over 7 obstacles with a 2-minute rest between runs) followed by a rifle marksmanship task on 3 occasions ([T.sub.1], [T.sub.2], and [T.sub.3]), each separated by 5 days. They also completed a bench press protocol (5 sets to failure at 70% of 1 repetition maximum) and answered the Profile of Mood States questionnaire during each test session. Testing was done 3 times. No supplementation was given before [T.sub.1]. Supplementation was provided using sports bars, with both groups receiving P1 bars between [T.sub.1] and [T.sub.2], whereas from [T.sub.2] to [T.sub.3] the Cr group consumed 24 g per day of Cr monohydrate in sports bars and the P1 group consumed an equal amount (kilocalories) of P1 sports bars. Creatine usage resulted in a significant (14%) increase in total bench press repetitions (p [less than or equal to] 0.05), but no difference between groups in obstacle course run times for the 3 runs from [T.sub.2] to [T.sub.3]. Marksmanship or mood was not affected by Cr supplementation. An increase of 1.4 kg in body mass (p [less than or equal to] 0.005) and a 0.5% decrease in percent body fat (p [less than or equal to] 0.05) were observed after Cr ingestion. Creatine supplementation over 5 days improved performance during a controlled strength test but did not significantly improve military obstacle course performance. Key Words: sport nutrition, dietary supplementation, ergogenic aids, exercise training

Background Underreporting of food intake has been commonly observed. We hypothesized that experience with recording dietary information might increase the accuracy of the records. To test this hypothesis, we compared energy intake and energy expenditure in dietitians--who are experienced in recording food intake--with those of non-dietitians, whose only exposure to training to record food was in the context of this trial. Subjects/setting Subjects for this study were 10 female registered dietitians and 10 women of comparable age and weight who were not dietitians. Design This study compared the energy intake obtained from 7-day food records with energy expenditure measured over the corresponding 7-day period using doubly labeled water. Statistical analysis Data were compared by an analysis of variance Methods All subjects were trained to provide a 7-day weighed food intake record. Energy expenditure was measured with doubly labeled water over the 7 days when the weighed food intake record was obtained. A total of 10 dietitians and a control of group of 10 women of similar age and weight were recruited for this study. Participants were told that the goal was to record food intake as accurately as possible, because it would be compared with the simultaneous measurement of energy expenditure determined by doubly labeled water. Results: The energy expenditure of the dietitians and controls were not different (2,154±105 [mean±standard error of the mean] kcal/day for dietitians and 2,315±90 kcal/day for controls). The dietitians underreported their energy intake obtained from the food records by an average of 223±116 kcal/day, which was not different from their energy expenditure. Participants in the control group, as hypothesized, significantly underreported their energy intake (429±142 kcal/day, P Conclusion Dietitians estimated their energy intake more accurately than non-dietitians, suggesting that familiarity with and interest in keeping food records may lead to more reliable estimates of energy intake., The introduction of doubly labeled water as a technique for measuring energy expenditure in animals (1,2) and human beings (3,4) has profoundly changed the interpretation of energy intake estimated from [...]

The Dietary Approaches to Stop Hypertension (DASH) clinical trial demonstrated that a diet that emphasizes fruits, vegetables, and low-fat dairy products, includes whole grains, nuts, fish, and poultry, and is reduced in fats, red meats, sweets, and sugar-containing beverages can be highly effective in lowering blood pressure. The National High Blood Pressure Education Program now suggests the DASH diet for preventing and managing hypertension. For persons modifying their diets, the DASH diet offers varied choices. However, simultaneously modifying several dimensions of a diet can be challenging, even for knowledgeable and motivated persons. Persons who are uncertain about modifying their diet may become overwhelmed by the needed dietary changes. Dietitians and other health care practitioners can help patients adopt the DASH diet by exploring possible ambivalence, increasing motivation, and strengthening commitment to change; encouraging patients to select dietary modifications that will fit their lifestyle; and, finally, offering information about how to change their eating behavior. In this article, we offer dietary advice and counseling suggestions for tailoring interventions to match patients' readiness for adopting the DASH diet., Hypertension affects about 25% of US adults and is a leading contributor to morbidity and mortality from coronary heart disease, stroke, peripheral vascular disease, and renal insufficiency (1). Lifestyle modifications […]

A large body of evidence suggests that several nutrients are related to blood pressure. Less is known about the eating patterns of special populations, such as those at risk for hypertension, or how demographic factors affect the diets of these populations. This article characterizes the usual diets of participants before they enrolled in the Dietary Approaches to Stop Hypertension (DASH) trial. During screening for DASH, 380 participants completed the National Cancer Institute food frequency questionnaire. Nutrient and food group intake, the Keys score (a measure of a diet's atherogenicity), and the Diet Quality Index were estimated from the food frequency questionnaire. The effects of age, sex, race, baseline weight, and education on these dietary factors were assessed among DASH participants and compared with similar data from the Third National Health and Nutrition Examination Survey and other published reports. Among DASH participants, African-Americans reported lower intakes of dairy products (P[less than].001), calcium (P[less than].001), and magnesium (P[less than].05) than did whites. Older women reported greater intakes of calcium, magnesium, and potassium (all P[less than].05) and less fat (P[less than].05) than did younger women. Older men consumed fewer servings of fruits (P[less than].03), less vitamin C (P[less than].05), and had a higher Keys score (P[less than].05) than did younger men. Heavier (body mass index [greater than or equal to]25) participants reported lower intakes of protein and potassium, but higher fat and energy intakes (all P[less than].05). Taken together, these data show that younger, overweight African-American women have the least healthful diets, because they consume more atherogenic foods and fewer of the nutrients related to decreased blood pressure. Overall Diet Quality Index scores did not differ between African-American and white participants. Despite differences in dietary assessment methods between the population samples of DASH and the Third National Health and Nutrition Examination Survey, within each population sample patterns of micronutrient intake were similar between African-American and white participants., Diet modification is a critical aspect of any effective strategy for hypertension prevention and control (1). Most recently, an eating pattern tested in the Dietary Approaches to Stop Hypertension (DASH) […]

The Dietary Approaches to Stop Hypertension trial involved 4 clinical sites at which 459 participants (in 5 cohorts) were fed 3 dietary patterns over 11 weeks per cohort. The 3 patterns were a control diet, a fruits and vegetables diet, and a combination diet. Before the intervention, key nutrient levels in each diet were validated at 2 energy levels (2,100 and 3,100 kcal) by chemical analysis of the prepared menus. During intervention, diets were sampled across all cohorts, sites, and energy levels, and 7-day menu cycle composites were assayed. In general, sodium, potassium, calcium, and magnesium in the validated menus for each diet/energy level met the nutrient targets, though moderate variability was evident among individual menus, particularly for potassium, calcium, and magnesium. However, as intended, there was clear separation and no overlap in mineral levels in individual menus of diets that were designed to differ. During intervention, macronutrient contents met nutrient goals. Sodium, potassium, calcium, and magnesium in the diets generally met target levels, though potassium in the fruits and vegetables diet was 11% to 23% below target. There were no consistent differences in nutrient levels between sites. The mean nutrient levels in the validated menus and diets sampled during intervention were in excellent agreement with each other, though sodium was somewhat higher (~6%) in the diets from intervention vs validation. These results indicate the success of the quality control measures implemented and suggested consistent overall diet composition throughout the 28 months during which the study was conducted., As an intervention technique, controlled feeding is valuable for testing the efficacy of diets in modifying disease processes or outcomes. Computerized food composition databases are often used to design diets […]

The Dietary Approaches to Stop Hypertension trial was a randomized, multicenter, controlled feeding study to compare the effect on blood pressure of 3 dietary patterns: control, fruits and vegetables, and combination diets. The patterns differed in selected nutrients hypothesized to alter blood pressure. This article examines the food-group structure and nutrient composition of the study diets and reports participant nutrient consumption during intervention. Participants consumed the control dietary pattern during a 3-week run-in period. They were then randomized either to continue on the control diet or to change to the fruits and vegetables or the combination diet for 8 weeks. Sodium intake and body weight were constant during the entire feeding period. Analysis of variance models compared the nutrient content of the 3 diets. Targeting a few nutrients thought to influence blood pressure resulted in diets that were profoundly different in their food-group and nutrient composition. The control and fruits and vegetables diets contained more oils, table fats, salad dressings, and red meats and were higher in saturated fat, total fat, and cholesterol than was the combination diet. The fruits and vegetables and combination diets contained relatively more servings of fruits, juices, vegetables, and nuts/seeds, and were higher in magnesium, potassium, and fiber than was the control diet. Both the fruits and vegetables and combination diets were low in sweets and sugar-containing drinks. The combination diet contained a greater variety of fruits, and its high calcium content was obtained by increasing low-fat dairy products. In addition, the distinct food grouping pattern across the 3 diets resulted in substantial differences in the levels of vitamins A, C, E, folate, B-6, and zinc., Epidemiologic studies demonstrate that certain eating patterns are associated with a lower risk of a variety of diseases (1-4). A common practice in translating these patterns into testable, clinical hypotheses […]

Accuracy of computerized nutrient databases is an important consideration in selecting a nutrient analysis system. We project compared the nutrient content of daily menus calculated from 4 microcomputer programs to chemical analysis of menus analyzed for the Dietary Approaches to Stop Hypertension (DASH) trial. Thirty-six menus were entered at 2 independent DASH sites using the ESHA Food Processor, Minnesota Nutrition Data System, Moore's Extended Nutrient Database, and Nutritionist IV databases. Food prepared according to these menus was chemically analyzed at the Food Analysis Laboratory Control Center at Virginia Polytechnic Institute and State University, Department of Biochemistry, Blacksburg. Estimates for 13 nutrients were compared: energy, total fat, saturated fat, monounsaturated fat, polyunsaturated fat, carbohydrate, protein, cholesterol, calcium, potassium, magnesium, iron, and sodium. The overall intraclass correlation between the 2 sites' data entry was 0.998; thus, values were averaged for analyses. Databases varied significantly in their mean deviations from chemical analyses values for saturated, monounsaturated, and polyunsaturated fatty acids, potassium, magnesium, and iron (P [less than] .05); however, these differences were small ([less than]10%). Absolute deviations, which estimate the combined effect of bias and precision, were significantly different among databases for energy, saturated fatty acids, and polyunsaturated acids. Absolute differences from the laboratory values varied by [less than]15%, except for iron. All 4 databases were comparable in accuracy and precision and performed well. Criteria for database selection depends not only on overall database accuracy, especially for nutrients of interest, but also on the ease of use of the program, relevant features of the associated software, and cost., Computerized nutrient analysis systems are integral to the practice of dietetics (1). Nutrition researchers, in particular, rely heavily on nutrient analysis systems for a variety of purposes, including the assessment […]

Objective To describe the process and results of diet standardization, diet validation, and monitoring of diet composition, which were key components of protocol i of Dietary Effects on Lipoproteins and Thrombogehic Activity (DELTA-1), the initial protocol in a program of multicenter human feeding studies designed to evaluate the effects of amount and type of fat on lipoproteins and hemostasis parameters in various demographic groups. Design DELTA-1 was based on a randomized, blinded, crossover experimental design. Three diets were fed for 8 weeks to 103 healthy men and women aged 22 to 67 years at 4 field centers. Diet A, an average American diet, was designed to provide 37% of energy from fat, 16% of energy from saturated fatty acids (SFAs); diet B (step 1 diet) was designed to provide 30% of energy from fat, 9% of energy from SFA; and diet C (low SFA diet) was designed to provide 26% of energy from fat, 5% of energy from SFA. Key features of diet standardization included central procurement of fat-containing foods, inclusion of standard ingredients, precision weighing of foods - especially sources of fat and cholesterol-and use of standardized written procedures. Setting For menu validation, a set of 12 menus for each diet was prepared in duplicate and chemically assayed. For monitoring of diet composition during the study, an 8-day diet cycle (6 weekday and 2 weekend menus) was sampled by every field center twice during each of 3 feeding periods. Statistical analyses Means (±standard error) were calculated and compared with target nutrient specifications. Results DELTA-1 was able to provide a standardized diet that met nutrient specifications across 4 field centers over 24 weeks of participant feeding spanning a total of 8 months. Applications Prestudy chemical validation of menus and continuous sampling and assay of diets throughout the study are essential to standardize experimental diets and to ensure that nutrient target goals are met and maintained throughout a controlled multicenter feeding study., Epidemiologic, clinical, and laboratory evidence underlies current dietary recommendations for population-based prevention of coronary heart disease (1). Clearly, average blood cholesterol levels in the US population will decrease with a [...]

Objective To compare reported energy intake with energy expenditure using doubly labeled water (DLW). Additionally, we compared reported nutrient intakes of our subject population with national survey population data from the third National Health and Nutrition Examination Survey (NHANES III). Design This was a cross-sectional study of children, balanced by race and gender, primarily characterized by 4 body types: lean, obese, centrally fat, or peripherally fat. Subjects/setting Children (n = 118; mean age = 10 years) kept 8-day food records, with nutritionists recording weekday school lunch intakes. These subjects, assisted by their parents, recorded all breakfasts, dinners, snacks, and weekend lunches. Statistical analyses performed Data were analyzed using least squares analysis of variance with the general linear models procedure. Tukey's test was used for multiple comparisons of predicted treatment means. Results Mean daily energy intake was underreported by 17% to 33% of energy expenditure. The tendency to underreport increased with age. Underreporting occurred in all groups and subgroups studied. Reported mean intakes of vitamin A, vitamin E, vitamin B-6, calcium, zinc, and copper were less than 70% of the Recommended Dietary Allowance (RDA) for African-American girls, whereas African-American boys reported similarly low intakes of copper. On average, white girls reported intakes less than 70% of the RDA for zinc and copper, whereas white boys reported low intakes of copper (60% of the RDA). Reported intakes in general were somewhat lower than those reported in NHANES III. Applications/conclusions Dietetics professionals may modify the nutritional advice they give to patients/subjects based on food intake records and other data. For children, particularly, it is imperative that ethnic and gender differences be taken into consideration and that all foods eaten be accounted for as much as possible., Overweight among American children is considerably more prevalent than underweight (1). A 1995 study reported that American children consumed 11% more energy than recommended (2). Livingstone et al (3) noted [...]