Comparison of the Block and the Willett self-administered semiquantitative food frequency questionnaires with an interviewer-administered dietary history

The performances of two commonly used diet instruments, the Block and the Willett food frequency questionnaires, were compared with a longer, interviewer-administered diet history. Participants in a case-control study on diet and colon cancer were interviewed between 1990 and 1994 in northern California, Utah, and Minnesota by trained nutritionists using a validated diet history. Two separate subsamples of participants were asked to complete either the Block or the Willett questionnaire exactly 5 days after they completed the original diet history. Data were analyzed separately by subsample comparing either the Block or the Willett questionnaire with the original diet history by using means, correlations, quintile agreement, and odds ratios for the relation between several nutrients and colon cancer. The Block and the Willett questionnaires generally provided lower absolute intake estimates than did the original diet history; however, the Block questionnaire underestimated more than did that by Willett. Both correlations and quintile agreement were slightly better for the Willett questionnaire than for that by Block when compared with the original diet history. In general, point estimates obtained from either the Block or the Willett questionnaire fell within the confidence intervals of the estimates of the odds ratios obtained from the original diet history, and no real difference in significance levels appeared. Although the Block and Willett questionnaires differed slightly from each other and from our original diet history in estimating absolute nutrients and ranking or classifying individuals, they were very similar in their ability to predict disease outcome.     

The Malm? Food Study: the relative validity of a modified diet history method and an extensive food frequency questionnaire for measuring food intake

OBJECTIVE: To assess the relative validity of two diet assessment methods, an extensive quantitative food frequency questionnaire (method A) and a novel shorter quantitative food frequency questionnaire with a 14 day food record (method B). DESIGN: A randomized prospective cohort study. SETTING: General community. SUBJECTS: 206 residents of the town of Malm?, aged between 50-69 years, 101 men and 105 women who completed the methods during one year. METHODS: Both diet methods were designed to cover the whole diet and portion sizes were estimated using a booklet with 120 photographs; method A comprised 250 items and method B combined a two-week food record measuring lunch and dinner meals and a shorter 130 item quantitative food frequency questionnaire for average consumption of foods, snacks and beverages during the past year. An 18 day dietary record comprising six 3-day weighed records evenly distributed over one year served as a reference method. RESULTS: Pearson's correlation coefficients varied from 0.25 for fat intake to 0.84 for milk products for method A and from 0.32 for fish to 0.88 for meat for method B. Correlations for most food groups ranged between 0.50-0.80, and were higher for method B. Only small changes were noted after adjustment for energy intake. On average for most food groups categorization of subjects into quartiles, 55% of subjects belonging to the lowest quartile, and 57-59% of those belonging to the highest quartile for method A and B were correctly classified. CONCLUSION: A combined food record with a quantitative food frequency questionnaire is a better tool for food assessment than an extensive food frequency questionnaire.     

Development of data-based semi-quantitative food frequency questionnaire for dietary studies in middle-aged Japanese

BACKGROUND: We designed a data-based semi-quantitative food frequency questionnaire to clarify the relationship between food intake and lifestyle-related diseases among middle-aged Japanese. METHODS: A total of 351 middle-aged individuals were recruited to a one-day weighed diet record survey in 1994. In all, 586 foods were consumed. Intake of 31 nutrients including energy, protein, fat, carbohydrate, vitamins, minerals and dietary fiber by food was computed by multiplying the weight of food consumed by its nutrient content. First, 252 foods with up to 90 cumulative % contribution to nutrient intake were selected. Of these, foods having apparently the same/similar nutrient content were combined into 206 foods by research dietitians. Next, 183 foods with up to 0.90 cumulative multiple regression coefficient and 90 cumulative % contribution were chosen. At this stage an additional food grouping was made. RESULTS: Finally, 102 foods/recipes were included in the questionnaire: rice (2 items), bread and noodles (11), eggs, milk and dairy products (10), soybean, soybean products and other beans (7), meat including beef, pork and chicken (12), fish (5), other fish, shellfish and fish products (10), green-yellow vegetables (8), other vegetables and mushrooms (7), edible roots (2), seaweeds (3), seeds (2), fruits (8), beverages (7) and confectioneries (8). The frequencies were classified into eight categories. Portion size was calculated for the respective foods largely from the one-day weighed diet record. CONCLUSIONS: The developed semi-quantitative food frequency questionnaire substantially covered the intake of 31 nutrients and may be competent to rank middle-aged Japanese efficiently.     

Use of food quotients in human doubly labeled water studies: comparable results obtained with 4 widely used food intake methods

Information on the macronutrient composition of the diet is needed in doubly labeled water studies to convert measured rates of carbon dioxide production into values for total energy expenditure. There is no general consensus, however, about the best method to determine food intake for this purpose. Four common methods of measuring food intake (7-day weighed food intake, 24-hour recall, and Fred Hutchinson Cancer Research Center/Block and Willett food frequency questionnaires) were tested for their ability to provide comparable food quotient and total energy expenditure data in doubly labeled water studies in 10 young and 10 older women. All methods gave mean values for total energy expenditure that were within 1% of each other. Individual values obtained using the 24-hour recall and food frequency questionnaires were within +/- 3% (standard deviation) of values determined using data from the 7-day weighed food record. These results suggest that it is not necessary to use time-consuming and expensive 7-day food records in doubly labeled water studies; instead, food intake data obtained more easily by 24-hour recall or food frequency questionnaire can provide comparable data.     

Estimation of the use of dietary supplements in the National Diet and Nutrition Survey: people aged 65 years and Over. An observed paradox and a recommendation

OBJECTIVE: To compare the evidence derived from blood biochemical status indices with the evidence from a questionnaire and from a 4-day weighed dietary record of micronutrient supplement use in the British National Diet and Nutrition Survey (NDNS) of People Aged 65 Years and Over; to resolve some apparent incompatibility between nutrient intake and status estimates, and to recommend an approach towards supplement recording that should improve accuracy. DESIGN: The survey procedures described in the National Diet and Nutrition Survey Report (1998) included a health-and-lifestyle questionnaire, a 4-day weighed diet record, and fasting blood and urine sample for biochemical indices, including a wide range of micronutrients. SETTING: Eighty randomly selected postcode sectors from mainland Britain during 1994-1995. SUBJECTS: Of 2060 people interviewed, 1467 provided a blood sample and 1217 provided both a blood sample, and a complete 4-day diet record. About 20% were living in institutions such as nursing homes, and the remainder were living in private households. RESULTS: After assigning the subjects to four categories by the use of dietary supplements (A, those not taking supplements (by questionnaire or by the 4-day record); B, those taking supplements (excluding prescribed ones) by questionnaire only; C, those taking supplements by 4-day record only; and D, those taking supplements by both questionnaire and 4-day record), these categories were then compared with respect to estimated total nutrient intakes and blood biochemical indices. Those in category B had estimated (4-day) nutrient intakes (from foods and supplements) that were indistinguishable from those in category A, but had biochemical indices that indicated significantly higher dietary intakes of several vitamins. CONCLUSIONS AND RECOMMENDATION: The 4-day weighed intake record may not have identified all of the subjects who were regularly taking micronutrient supplements in amounts sufficient to improve their biochemical status. Because survey respondents may use supplements irregularly or change their usual patterns of supplement use during a period of intensive diet-recording, it is important to design a dietary instrument that will minimise this potential source of inaccuracy. We therefore recommend that population surveys in which an accurate estimate of micronutrient intakes is required, from supplements as well as from food, should record supplement use for a period longer than 4-days. It is likely that a better estimate of long-term intakes can be achieved by combining a 4-day weighed diet record with a structured recall or several weeks of diary records, which focus specifically on the use of supplements.     

Dietary assessment in the elderly: validation of a semiquantitative food frequency questionnaire

OBJECTIVE: The study was conducted to assess the relative validity of a 170-item semiquantitative food frequency questionnaire (SFFQ) adapted for use in the elderly. DESIGN AND SUBJECTS: The study was carried out in a sample of 80 men and women aged 55-75 y participating in a community based prospective cohort study in Rotterdam, The Netherlands. The two-step dietary assessment comprised a simple self-administered questionnaire (20 min) followed by a structured interview with trained dietitians (20 min) based on the completed questionnaire. Multiple food records (FR) collected over a one year period served as reference method. 24 h urine urea was used as indirect marker for protein intake. RESULTS: Compared with FR, the SFFQ generally overestimated nutrient intake as reflected by difference in means and the ratio of SFFQ to FR. Energy adjustment reduced the observed overestimation. Pearson's correlation coefficients varied from close to 0.5 to about 0.9 for crude data, and after adjustment for age, sex, total energy intake, and for within-person variability in daily intake for 0.4-0.8. Cross-classification into quintiles resulted in correct classification into the same or adjacent quintile of 75.8% for crude and 76.8% for energy-adjusted data. Validation of protein intake estimated by SFFQ with protein excretion from 24h urine urea indicated overestimation of protein intake by SFFQ. Spearman correlation coefficient between protein intake estimated from urea excretion and SFFQ was 0.67. CONCLUSIONS: Adaptation of a SFFQ for use in the elderly resulted in a valid and time-efficient dietary assessment instrument. Its ability to adequately rank study subjects according to their dietary intake support its application in epidemiological studies in the elderly.     

Garlic, onion and cereal fibre as protective factors for breast cancer: a French case-control study

The role of diet on breast cancer risk was investigated in a case-control study of 345 patients diagnosed with primary breast carcinoma between 1986 and 1989 in the north-east of France (Lorraine). For each case, one control was matched for age (+/-3 years) and socio-economic status. The dietary history questionnaire consisted of a self-administered food frequency questionnaire, a 6-day food diary and an energy expenditure record. It also elicited personal characteristics and medical history. While taking into account total caloric intake and established risk factors, breast cancer risk was shown to decrease as consumption of fibre (p value for trend = 0.03), and garlic and onions (p value for trend <10(-6)) increased. This study also supports the epidemiologic evidence that saturated fat intake and breast cancer risk are associated in post-menopausal women (p value for trend = 0.03). Conversely, it suggests that unsaturated fat intake could lower the risk in the same subgroup (p value for trend = 0.03). Our findings on protective factors of breast cancer could induce effective preventive measures and warrant further experimental investigations to isolate specific subfractions.     

Cumulative trauma disorders in the upper extremities: reliability of the postural and repetitive risk-factors index

OBJECTIVE: To determine the extent to which incorporating fat-modified foods into a food frequency questionnaire influences the agreement of energy and nutrient estimates with estimates obtained from food records. DESIGN: Subjects completed four 2-day food records at 3-month intervals. At the end of the recording period, a food frequency questionnaire was administered to assess usual daily intake during the preceding year. SUBJECTS/SETTING: One hundred and three subjects selected from a population-based sample of adults participating in the Beaver Dam Eye Study. STATISTICAL ANALYSES PERFORMED: Subjects were categorized into three groups on the basis of their frequency of consumption of fat-modified foods. For each group, correlations were calculated between food record estimates and estimates obtained from the original food frequency questionnaire, the original with a low-fat option, and the fat-modified questionnaire. RESULTS: For persons categorized as high consumers of fat-modified foods, incorporating questions regarding the consumption of these products resulted in higher correlations with food record estimates (original vs fat-modified version) for percentage of energy from total fat (.32 vs .47), saturated fat (.20 vs .41), oleic acid (.32 vs .50), and linoleic acid (.40 vs .46). High consumers differed in several characteristics that could be associated with disease risk (eg, higher ratios of serum total cholesterol to high-density lipoprotein cholesterol). CONCLUSIONS: Failure to account for the consumption of fat-modified foods in epidemiologic studies may result in misclassification of fat exposures. Because patterns of misclassification could be different for those at risk for disease, results of epidemiologic studies could be biased if these foods are excluded. Thus, incorporating fat-modified foods into food frequency questionnaires will improve the ability of researchers to correctly classify fat exposures and to evaluate potentially important relationships between fat intake and disease risk.     

Interviewer versus self-administered questionnaires in developing a disease-specific, health-related quality of life instrument for asthma

We wished to determine the extent to which respondents provided the same answers to a health-related quality of life (HRQL) questionnaire in self- and interviewer-administered forms. One hundred and fifty patients with asthma who were symptomatic or required treatment at least once a week, and had airway hyperresponsiveness to methacholine aerosol (PC20 < 8.0 mg/ml) participated. Patients completed a 152-item HRQL questionnaire in both interviewer and self-administered forms, separated by a 2-week interval, the order determined by random allocation. The percentage of items endorsed by the self-administered approach was significantly higher than that of the interviewer-administered approach overall (46.9 vs 35.8%) (p < 0.0001). The difference was consistent across all six domains; the absolute difference in the proportion of items endorsed varied from 8.9 to 12.3%. The intraclass correlations for the proportion of subjects endorsing an item was 0.84. Self- and interviewer-administered questionnaires yield very similar results in discriminating between subjects, but the self-administered version shows systematically greater HRQL impairment.     

Ultrastructural criteria that prove the similarities between amphibian and human tumors

The relationship between selected foods and nutrients and breast cancer risk was investigated in strata of age and menopausal status using data from a case-control study on breast cancer conducted between June 1991 and April 1994 in six Italian areas. Cases were 2,569 women with histologically confirmed incident breast cancer admitted to the major teaching and general hospitals of the study areas; controls were 2,588 women with no history of cancer admitted to hospitals in the same catchment area as cases for acute, nonneoplastic, nongynecological conditions unrelated to hormonal or digestive tract diseases or to long-term modifications of diet. Dietary habits were investigated using a validated food frequency questionnaire, including 78 foods or food groups. Among food groups, bread was directly and significantly related to breast cancer risk in older women and, consequently, in postmenopause, whereas the protection conferred by fish consumption was stronger in postmenopause and that exerted by raw vegetables was stronger in premenopause. Among nutrients, unsaturated fatty acids were inversely related to breast cancer risk, the association being stronger in postmenopausal and elderly women. The pattern was similar for total fats. For starch, available carbohydrates, and total proteins, no heterogeneity emerged across strata of age and menopausal status. Among micronutrients, protection diminished with increasing age for beta-carotene and calcium, whereas no heterogeneity emerged for vitamin E. Thus this age-specific analysis of the largest investigation to date on diet and breast cancer did not show any consistent pattern of breast cancer risk in relation to selected dietary factors across strata of age and menopausal status.     

Bias in diet assessment methods--consequences of collinearity and measurement errors on power and observed relative risks

BACKGROUND: If several risk factors for disease are considered in a regression model and these factors are affected by measurement errors, the observed relative risk will be attenuated. In nutritional epidemiology, several nutrient variables show strong correlation, described as collinearity. The observed relative risk will then depend not only on the validity of the chosen diet assessment method but also on collinearity between variables in the model. METHODS: The validity of different diet assessment methods are compared. The correlation coefficients between common nutrients and foods are given using data from the Malm? Food Study. Intake of nutrients and foods were assessed with a modified diet history method, combining a 2-week food record for beverages and lunch/dinner meals and a food frequency questionnaire for other foods. The study population comprised 165 men and women aged 50-65 years. A multivariate logistic regression model is used to illustrate the effect of collinearity on observed relative risk (RRo). RESULTS: A moderate to high correlation between risk factors will substantially influence RRo even when using diet assessment methods with high validity. Methods with low validity might even give inverse RRo. CONCLUSION: It is stressed that caution must be exercised and only a selected number of variables should be included in the model, especially when they are highly intercorrelated, since RRo might be severely biased.     

Comparison of food frequency questionnaires: the reduced Block and Willett questionnaires differ in ranking on nutrient intakes

Food frequency questionnaires, major tools in epidemiologic studies, are often criticized for biased and imprecise intake estimates. The aim of this study was to compare the performance of two widely used food frequency questionnaires, a reduced 60-item Block questionnaire and a 153-item Willett food frequency questionnaire, relative to three 24-hour recalls administered by telephone. The dietary data were collected in 1991 from a group of healthy women age 25-49 years (n=101) during the baseline period of a weight-loss intervention study in Minneapolis, Minnesota. Total energy and macro- and micronutrient intakes were compared across methods by using four analytic approaches: comparison of means and correlation coefficients, regression analysis, and estimation of percent agreement between each questionnaire and recalls. The Block instrument showed an overall underestimation bias, but was more successful in categorizing individuals on percent energy from fat and carbohydrate intakes than was the Willett instrument. The Willett instrument showed no overall underestimation bias and was more successful in classifying individuals on vitamin A and calcium intakes. Diverging performance characteristics of diet assessment methods have an implication for the design of studies, interpretation of results, and comparison of findings across studies.     

Quality improvement in gastrointestinal endoscopy: microbiologic surveillance of disinfection

OBJECTIVE--To study the association between diet and newly diagnosed NIDDM in the Wanigela people of Papua New Guinea, a population with an extraordinary susceptibility for NIDDM. RESEARCH DESIGN AND METHODS--We performed a case-control study of Wanigela people from an urban settlement (Koki). Case patients (n = 145) were asymptomatic subjects in whom NIDDM was newly diagnosed using a 2-h 75-g oral glucose tolerance test. Control subjects with glucose tolerance (n = 140) were group-matched on the basis of age and sex. A detailed food frequency questionnaire was used to determine energy and nutrient intakes. Nutrient intakes were compared directly and after calculation of residuals to correct for energy intake. Odds ratios for NIDDM were computed in relation to total energy and specific nutrient intakes, adjusting for age, sex, BMI, waist-to-hip ratio, and physical activity. RESULTS--There were no differences between case patients and control subjects in mean values of total energy-adjusted nutrient intakes. In logistic regression models, neither total energy nor any specific nutrients were associated with increased risk of NIDDM. When models were repeated with nutrients categorized by textiles, there were marginally significant associations with intakes of fiber (positive) and cholesterol, protein, and sugar (negative). CONCLUSIONS--This study does not support the hypothesis that saturated fat is an independent risk factor for NIDDM. The weak associations of intakes of fiber and cholesterol with newly diagnosed NIDDM were in the opposite directions to those expected and are probably due to chance. Relative homogeneity of diet within a community, such as that found in Koki, makes it difficult to demonstrate risk factor-disease associations. However, changes in diet and reduced levels of physical activity accompanying urbanization undoubtedly contribute to the high prevalence of obesity observed in this community, and hence diet is likely to contribute to NIDDM risk at least by indirect means.     

Nutrient intake and dental health in school children

Diet refers to the customary allowance of food and drink taken by a person from day to day. The diet may affect dental caries by reacting with the enamel surface and by serving as a substrate for cariogenic microorganisms. This study examined the role of specific nutrients in the caries experience of elementary school children. 120 children aged between 6-11, who attended the Pedodontics Department of Marmara University, Faculty of Dentistry for routine dental treatment received a dental examination, parent interview, and a 3-day diet diary. The diary was completed adequately for 100 children (83%). The average daily intake of nutrients were computed and total sugar consumption and Ca/P ratio were calculated. Each child's gender, age, fluoride history, socio-economic state of the family, previous dental experience, brushing habit, and nutrient intake were examined as independent variables. No association was apparent between dental caries and the intake of specific nutrients or Ca/P ratio, except with total sugar consumption.     

Evidence for leptin regulation of food intake in humans

The adipocyte hormone leptin regulates body weight in mice by decreasing food intake and increasing energy expenditure. Whether leptin is of physiological importance for these processes in humans is, however, not clear. We therefore studied the relation between leptin and habitual food intake in 64 healthy postmenopausal women. Dietary habits were assessed with a modified diet history method. Body fat content was measured using bioelectrical impedance. In the 64 women, aged 58.6+/-0.4 yr (mean+/-SD), serum leptin was 19.3+/-12.7 ng/mL, body mass index was 25.0+/-3.5 kg/m2, body fat content was 31.6+/-4.3%, fasting glucose was 4.6+/-0.5 mmol/L, and fasting insulin was 56+/-21 pmol/L. Leptin levels were negatively correlated to total energy intake (r=-0.34; P=0.006), carbohydrate intake (r=-0.36; P=0.004), and total (r=-0.27; P=0.034) as well as saturated fat intake (r=-0.31; P=0.014). Leptin was correlated to the absolute, but not to the percent, intake of these nutrients. When normalized for body fat content, the correlations remained significant. Our results suggest that plasma leptin is involved in the physiological regulation of food intake in humans, and that leptin is related to the quantity rather than the quality of habitual food intake.     

Sucrose intake in Germany

The present investigation reevaluated the German National Food Consumption Survey in order to obtain data on sucrose intake and food sources of sucrose intake in Germany. Moreover, it focused on the effect of sucrose intake on nutrient intake. By means of the food composition data base Bundeslebensmittelschlüssel, version II.2, 7-days dietary records of a representative sample of 15,838 persons aged 4 years and older were analyzed. The relation between sucrose and nutrients intake was investigated by variance and regression analyses. Low, moderate, and high sucrose intake categories were defined by means of sucrose density quartiles and comparisons were made for the percentages of persons meeting the German nutrient intake recommendations. Mean daily sucrose intake ranges between 43.2 g/d (f, 51-64 years) and 82.3 g/d (m, 13-14 years). The mean contribution of sucrose to total energy intake is highest with 14% in young age (4-6 years) and decreases to 9% and 7% in 51-64 year old women and men, respectively. The food groups "table sugar", "confectionery and ice cream", "biscuits, cake and pastries", "preserves", "dairy products", and "non-alcoholic beverages" are the main sucrose sources with varying importance in different age groups. The average amount of naturally occurring sucrose in the Germans' diet is estimated to 15-25% of total sucrose intake. Sucrose contributes 80-90% to total disaccharides intake in Germany. With each gram of sucrose the intake of energy rises on the average by 12.5 kcal (52.4 kJ), of protein by 0.3 g (9% of the energy increase), of fat by 0.5 g (34%), and of carbohydrates by 1.8 g (57%). Consequently, the higher the sucrose content of a diet, the lower is the contribution of fat to total energy intake. In contrast, the energy-adjusted effect of sucrose was found to be negative for energy-providing nutrients (except mono- and disaccharides) as well as for all the selected micronutrients, except calcium, vitamin E, vitamin C, and dietary fiber. Accordingly, the comparison between moderate and high sucrose consumers revealed a lower percentage of persons meeting nutrient intake recommendations in the high sucrose category under the condition of a comparable energy intake. This unfavorable effect of high sucrose intake is most prominent in 4-6 year old boys and girls as the groups with the highest sucrose intake. Since from the present data no exact figure for a sucrose or sugars intake recommendation can be deduced, it is suggested to keep on the WHO recommendation for a moderate sugar intake of 10% of energy intake.     

Monitoring dietary change in a low-fat diet intervention study: advantages of using 24-hour dietary recalls vs food records

OBJECTIVE: The purpose of the study was to evaluate two methods of dietary assessment for monitoring change in fat intake in a low-fat diet intervention study. DESIGN: The two dietary assessment methods were a 4-day food record (4DFR) and an unannounced 24-hour dietary recall conducted by telephone interview (referred to as a telephone recall [TR]). Subjects were assigned randomly to either a low-fat diet intervention group or a control group that received no counseling about fat intake. Dietary data were collected at baseline, 6 months, and 12 months. SUBJECTS: Two hundred ninety postmenopausal women with localized breast cancer were recruited at seven clinical centers in the United States. STATISTICAL ANALYSIS: Analysis of variance was used to test for significant differences in mean fat and energy intakes. RESULTS: Three sources of error were identified: (a) an instrument effect, suggesting underreporting at baseline of approximately 8% in mean energy intake and 11% in mean fat intake in the TR group compared with the 4DFR group (P = .0001); (b) a repeated measures effect observed for the 4DFR, suggesting underreporting of approximately 7% for energy intake and 14% for fat intake in the control group at 6 and 12 months compared with baseline values (P < .001); and (c) an adherence effect (or compliance bias), suggesting greater compliance to the low-fat intervention diet when subjects were keeping food records than when estimates were based on the unannounced TR. Compared with the TR, the 4DFR overestimated the extent of fat reduction in the low-fat diet intervention group by 41% (P = .08) and 25% (P = .62) at 6 and 12 months, respectively. APPLICATION: Multiple days of unannounced 24-hour recalls may be preferable to multiple-day food records for monitoring dietary change in diet intervention studies.     

Assessment of trans-fatty acid intake with a food frequency questionnaire and validation with adipose tissue levels of trans-fatty acids

Past studies of the association of trans-fatty acid intake with coronary heart disease have been hindered by the lack of a database on the trans-fatty acid content of various foods. The authors used new data from the US Department of Agriculture to estimate trans-fatty acid intake using a self-administered food frequency questionnaire (FFQ), and they assessed the validity of the FFQ by comparing the dietary estimates with trans-fatty acid concentrations in adipose tissue. The 1996 study included 27 women and 24 men aged 51-78 years. The mean consumption of total trans-fatty acids estimated from the FFQ was 2.24 g per day and 5% of total dietary fat. The mean concentration of total trans-fatty acids in buttock adipose tissue was 4.7% of total fatty acids. Pearson correlations between total dietary intake of trans-fatty acids and total trans-fatty acid levels in adipose tissue were 0.67 (95% confidence interval (CI) 0.36-0.84) among men and 0.58 (95% CI 0.26-0.79) among women. After adjustment for energy intake, age, and body mass index, the correlation coefficients were 0.76 (95% CI 0.51-0.89) among men and 0.52 (95% CI 0.17-0.75) among women. The FFQ validated in this study is an important new tool for assessing usual intake of trans-fatty acids.     

Life-threatening hemorrhage and exsanguination from Crohn''s disease. Report of four cases

This study evaluates the reproducibility of food intake reports in a 45-item self-administered food frequency questionnaire (FFQ) used for a diet study in a large cohort in New York State. The first FFQ was mailed in 1980, and a followup version containing 75 food items was mailed in 1988 to the eligible original participants. Reproducibility was evaluated by comparing the subjects' 1988 responses with their original 1980 responses. Spearman's correlations ranged from 0.27 (nuts other than peanuts) to 0.56 (summer squash) in men and from 0.25 (tomatoes) to 0.51 (summer squash) in women. Analyses stratified by age, education, marital status, body mass index, cigarette smoking, alcohol drinking, and special diet revealed few substantial differences in correlations. The moderate reproducibility of foods in this questionnaire indicates that brief FFQs may be a useful tool to study food intake and chronic disease relationships in this population.     

Consumption of meat, animal products, protein, and fat and risk of breast cancer: a prospective cohort study in New York

Epidemiologic studies have focused on the association between diet and breast cancer with conflicting results. Whereas a majority of case-control studies indicate a role for the intake of total fat and saturated fat, most prospective cohort studies either are negative or indicate very modest associations. Only a few authors have examined the role of meat intake in relation to breast cancer risk. The aim of this study was to examine the relation between risk of breast cancer and dietary intake of meat, animal products, fat, and protein. Between 1985 and 1991, we recruited 14,291 New York City women in a prospective cohort study of endogenous hormones, diet, and cancer in which they reported on their recent diet using a food frequency questionnaire self-administered at enrollment. From the cohort, 180 invasive breast cancer cases diagnosed before December 1990 and five times as many controls, individually matched by age, calendar time at enrollment, menopausal status, and, if premenopausal, phase of menstrual cycle, were included in a nested case-control study. There was an evident increase in the relative risk (RR) of breast cancer for increasing consumption of meat. Women in the upper quintile of meat consumption, as compared with the lowest quintile, had an energy-adjusted RR of 1.87 (95% confidence interval = 1.09-3.21). There was a modest RR increase in the upper quintile of total and saturated fat and no apparent association for other types of fat, protein, dairy products, poultry, or fish.(ABSTRACT TRUNCATED AT 250 WORDS)