食物频率问卷法评估人群能量和营养素摄入量的准确性验证

目的:食物频率问卷法(FFQ)问卷评估人群膳食能量和营养素摄入量的准确性进行验证。方法:使用3d称重法(WFR)和FFQ收集北京市130名35～49岁健康成人食物摄入资料,计算出其能量和营养素的摄入量并加以比较。结果:由食物WFR计算到的研究对象能量摄入为9.6MJ/d,蛋白质、脂肪和碳水化物摄入分别为82.1、87.5和269.7g/d。由FFQ得到的能量摄入量为9.7MJ/d,蛋白质、脂肪和碳水化物摄入量分别为88.3g/d、113.9g/d和248.8g/d,两种方法调查的膳食能量、蛋白质及其供能比无显著性差异,FFQ显著高估膳食脂肪摄入量(高估27.2%),碳水化物摄入量则被低估(低估10.8%)。FFQ得到的膳食维生素和矿物质的摄入量普遍高于WFR,但低估维生素E、铁和硒的摄入量。由FFQ得到的能量和营养素摄入,除维生素C、胡萝卜素和视黄醇当量外,均与WFR显著正相关,相关系数在0.22~0.51之间,但在调整年龄、性别和膳食能量摄入量的影响后,FFQ对膳食脂肪、维生素B1、钠和磷摄入量的估计与WFR相关的显著性消失。结论:FFQ可以用于评估膳食能量、蛋白质、碳水化物、维生素A、维生素B2、尼克酸、钾、钙、锌和硒的摄入量,但FFQ不适于评估膳食脂肪、视黄醇当量、胡萝卜素、维生素B1、维生素C、维生素E、钠、铁和磷的摄入量。     

Comparison of estimated nutrient intake by two methods: validation of a food frequency questionnaire

The validity of a quantitative self-administered food frequency questionnaire (FFQ) was tested by comparison with 7-d weighed food records (7DWR). Subjects for the study were 24 females between 20 and 43 years of age (mean = 24 years). The main aim of the FFQ was to classify subjects according to their total fat intake.
The mean nutrient intakes estimated by the FFQ were consistently and significantly higher than the estimates by the 7DWR. Rank correlations showed that the FFQ was able to rank subjects similarly for total energy intake, fat, alcohol and fibre intake as well as for the percentage contribution of macronutrients to energy intake. Intra-class correlations showed that the two methods did not agree at the individual level for energy and macronutrient intake except alcohol. These results suggest that the FFQ was suitable for ranking the subjects according to their total fat intake but was not suitable for estimating the individual nutrient intake or average nutrient intake of this relatively small group.     

Dietary assessment instruments for preschool children: reliability of parental responses to the 24-hour recall and a food frequency questionnaire

Nutrient intakes of preschool-age children were assessed with a 24-hour dietary recall and a 3-month food frequency questionnaire (FFQ). Parents of 55 preschoolers (mean age = 4.25 +/- 0.59 years) completed the recall and FFQ on two occasions 1 week apart. The recalls and FFQs were analyzed for energy, cholesterol, protein, total carbohydrate, calcium, sodium, potassium, and saturated, polyunsaturated, and monounsaturated fats; each nutrient was expressed as raw value, value per kg body weight, and value per 1,000 kcal. Test-retest reliability estimates for the 24-hour recall indicated significant variability in reported total energy intake, but stable reports of intake were observed for one or all units of expression for polyunsaturated fats, cholesterol, protein, total carbohydrate, calcium, and potassium. The FFQ showed significant positive test-retest reliability estimates for all nutrients for all units of expression. Comparison of the recall and FFQ data showed similar percentages of intakes of energy from fat, carbohydrate, and protein and significant correlations for reported intakes of cholesterol, protein, calcium, and potassium. Comparison of the recall and FFQ data with recall data from a comparable cohort showed lower reported intakes for our sample, with the exception of protein, carbohydrate, calcium, and potassium. If validation studies are successful, the FFQ may be useful in epidemiological studies of preschoolers' intakes over extended periods. The recall may prove to be a useful tool in the assessment of day-to-day variations in macronutrient intakes.     

What can people eat to meet the dietary goals: and how much does it cost?

In order to meet the UK dietary goals, changes in the usual diet will need to be made. We analysed the diets of 2340 middle-aged men and women in three English towns who had completed a 1-day food record. A majority consumed more fat, more sugar and less carbohydrate and fibre than recommended. Nutrient intakes for those meeting the goals were compared with those who did not meet them. Fewer subjects met a combination of goals, for example, only 7% m et al l three COMA fat goals. The 28 subjects who met a combination of the goals for total fat/saturated fat/PS ratio/carbohydrate or sugar/fibre (the combined goals group) were compared with a similar number (the average group) from subjects whose nutrient intakes were within the twenty-fifth and seventy-fifth percentiles. Nutrient and food intakes were compared. The combined goals group ate, for example, more cereals, wholemeal and brown bread and less white bread than the others. The average daily cost of the food intake for the combined goals group was (excluding alcohol) £2.03 and for the average group £1.86.     

Can a food frequency questionnaire be used to capture dietary intake data in a 4 week clinical intervention trial?

Collecting dietary data in the clinical research setting is labour intensive and can be burdensome for study participants. The aim of this study was to assess the agreement between data obtained from 2 different dietary assessment methods, a 74-item semi-quantitative food frequency questionnaire (FFQ) and 3-day weighed food records (WFR) used to estimate dietary intake over the preceding month. One hundred and fifty nine subjects, aged between 31 and 74 years (53 males, 65 females), enrolled in a clinical trial at the Commonwealth Scientific and Industrial Research Organisation, Division of Health Sciences and Nutrition, (CSIRO HSN) Adelaide, Australia. Group mean intakes and individual mean intakes estimated by the two measures were compared. One hundred and eighteen (91%) three-day WFR and their corresponding FFQ were analysed. Pearson correlation coefficients ranged from 0.22 for cholesterol to 0.78 for alcohol (median 0.41). Mean energy and nutrient intakes were within +/- 20% difference. The FFQ gave lower carbohydrate intake estimates, percentage energy from carbohydrate (P <0.001) and dietary fibre (P <0.05) and gave higher percentage energy from saturated fat estimates, poly-unsaturated fatty acids (P <0.001) and mono-unsaturated fatty acids (P <0.05). Subjects were also ranked into quintiles and the quintiles cross-tabulated. The FFQ classified more than two thirds of the subjects within +/-1 quintile difference for all nutrients. We conclude that this FFQ can capture similar information as WFR and may be used for estimation of dietary intakes over a relatively short time in clinical intervention trials.     

The nutrient and food intakes of 16–17 year old female dieters in the UK

A group of female teenage dieters was isolated from a larger national dietary survey of teenagers at 16–17 years of age. The dieting group included girls who both claimed to be dieting and who had energy intakes which were considered appropriate for weight loss, based on calculated reported energy intake to estimated basal metabolic rate cut-off points. The nutrient intakes and food choices of dieters (n= 204) were compared with a similar sample of non-dieters (n= 226) from the same cohort group. The mean reported energy intake of the dieters was 1604 kcals/day compared to 2460 kcals/day amongst non-dieters. The intakes of all the macronutrients in g/day were considerably lower amongst dieters, allowing for differences in region and social class, but when expressed as a percentage of energy intake, dieters had significantly lower intakes of fat and higher intakes of protein and intrinsic sugars, milk sugars and starch. No differences were seen in the percentage of energy provided by non-milk extrinsic sugars between the two groups. The intake of all micronutrients was substantially lower amongst dieters, allowing for regional and social class differences, and more than twice as many dieters as non-dieters failed to achieve the reference nutrient intake (RNI) for retinol equivalents, thiamin, riboflavin, folates, vitamin B12, vitamin B₆, zinc, copper and selenium. Reported food intake data for the two groups suggest that dieters consumed smaller quantities of most foods, although intakes of items associated with dieting such as low calorie soft drinks, low fat spread, skimmed milk, cottage cheese, yoghurt, salad vegetables, fruit and fruit juice were consumed in equal or greater amounts by dieters. Teenage dieters should be encouraged to include more nutrient-dense foods in their diets such as fortified breakfast cereals and low fat dairy products in order to obtain sufficient micronutrients from a lower calorie intake.     

Reproducibility and validity of a semi-quantitative food frequency questionnaire

The reproducibility and relative validity of a semi-quantitative food frequency questionnaire (FFQ) were evaluated. Subjects were 72 (36 men and 36 women) residents of N island, Shimane Prefecture in Japan, aged 50-76 years. The questionnaire was administered twice at an interval of one week (FFQ1, FFQ2), and 7-day weighing diet records were collected during that period. This protocol was conducted in summer and winter. The mean intakes for 11 nutrients calculated from the FFQ1 and FFQ2 were similar and, those from the FFQ1 were smaller than those from the diet records for all but fat and vitamin C. Pearson correlation coefficients assessing reproducibility between nutrient intakes from FFQ1 and FFQ2 ranged from 0.59 for vitamin C to 0.90 for carbohydrate. Validity was measured by comparing nutrient intakes from FFQ1 with those from the 7-day diet record, and Pearson correlation coefficients ranged from 0.15 for iron to more than 0.35 for total energy and macronutrients. These correlation coefficients showed slight difference by gender or age group, but did not vary materially between seasons. These data indicate that this questionnaire is reproducible but has some problems in validity.     

Plasma triacylglycerol and HDL cholesterol concentrations confirm self-reported changes in carbohydrate and fat intakes in women in a diet intervention trial

Diet intervention trials are currently testing whether reduced fat intake can reduce the risk and progression of breast cancer. Energy from dietary fat is generally replaced by energy from carbohydrate in these studies, and altering the proportion of energy from dietary carbohydrate and fat has been shown to affect plasma lipid concentrations in controlled feeding studies. The purpose of this study was to examine the effect of increased carbohydrate and reduced fat intakes on plasma lipids in a randomized, controlled trial that is testing the effect of diet modification on risk for recurrence and survival in women previously treated for breast cancer. Plasma concentrations of lipids and related factors were measured at enrollment and 1-y follow-up in 393 women enrolled in the trial. Dietary goals for the intervention group focused on an increase in vegetable, fruit and fiber intakes, and reduced fat intake. Women assigned to the intervention group significantly reduced fat intake (from 28.1 to 21.0% of energy), and significantly increased intakes of carbohydrate (from 56.9 to 65.3% of energy) and fiber (from 21.0 to 29.6 g/d) (P < 0.05). Body weight did not change significantly in either study group. A small but significant increase in fasting plasma triacylglycerol concentration, and decreases in HDL cholesterol and apoprotein-A1 concentrations, were observed in the intervention group (P < 0.05) but not in the comparison group. Changes in total cholesterol, LDL cholesterol, apoprotein-B, lipoprotein (a), and insulin concentrations, and in the LDL cholesterol/HDL cholesterol ratio, were not observed in either group. The lipid responses that were observed in this study provide biological evidence that validates the self-reported change in dietary intakes of fat and carbohydrate in response to the intervention efforts. The degree of change in these lipid concentrations was small and does not suggest increased cardiovascular disease risk.     

Did fat intake in the United States really decline between 1989-1991 and 1994-1996?

The objectives of this study were to determine changes in fat and energy intakes in the United States between 1989-1991 and 1994-1996, and to examine the implications of expressing fat intake in grams vs as a percent of total energy intake. The source of data was the Continuing Survey of Food Intake by Individuals. The results suggest that intake of energy rose between the 2 time periods, primarily due to higher carbohydrate intake. There was also a modest increase in fat intake. However fat intake, as a percent of total energy, declined. The higher energy intakes were primarily from beverages, especially soft drinks, food mixtures, grain snacks, and pastries. The primary sources of higher fat intakes were meat mixtures, vegetables, and some categories of the grain group. Similar trends in the Food Supply Series suggested that the changes observed were not entirely due to changes in survey methodology. Because the increase in fat intake was masked by the increase in energy intake, we conclude that assessing trends in fat intake as a percent of energy consumption can be misleading, unless information on total energy and fat intake, in grams, is also provided. These preliminary findings should be interpreted cautiously until they are confirmed by formal secular trend analyses.     

Non-starch polysaccharide intake in vegans and the relationship with energy distribution and mineral intakes

Background There is little information available about non-starch polysaccharide (NSP) intake in vegans. This study aimed to estimate the intake of NSP in the habitual vegan diet and to assess the relationship between NSP intake and energy distribution, and intakes of selected minerals.
Method NSP intake, energy distribution and intakes of calcium, magnesium, iron and zinc were estimated, using a 4-day weighed record, in 26 adult vegans (male n  = 11, female n  = 15) consuming their habitual diet.
Results Mean BMI values in males (22.0) and females (21.1) were significantly lower than the average for the UK population. Mean daily NSP intakes in males (27 g) and females (23 g) were higher than the dietary reference value (DRV) population average of 18 g day^–1, although six subjects had intakes below this and two male subjects had intakes below the DRV individual minimum of 12 g day^–1. Cereals were the major contributor to total NSP intakes. Mean contributions to total energy intake in males and females were in-line with the DRV. Mean calcium intakes were below the reference nutrient intake (RNI) while mean intakes of magnesium, iron and zinc were above the RNIs. There were significant positive correlations between NSP intake and calcium, magnesium, iron and zinc.
Conclusion Occasional low NSP intakes and, conversely, high intakes of NSP combined with marginal calcium intakes in some vegans are of concern. Further work is needed to assess food sources and NSP intakes in the current vegan diet.     

The CAFE computer program for nutritional analysis of the EPIC-Norfolk food frequency questionnaire and identification of extreme nutrient values

BACKGROUND: Food frequency questionnaires (FFQs) are widely used in nutritional epidemiology but no papers detail the development of the supporting programs and nutritional databases. The principles involved in data collection, processing and treatment of the European Prospective Investigation into Cancer Study (EPIC)-Norfolk Study FFQ and development of the structure and content of the Compositional Analyses from Frequency Estimates (CAFE) program for calculating nutrient intakes are described. Extreme nutrient values and derivation of cut-points for data exclusion are also discussed. METHODS: The FFQ was sent to 25,637 participants. To exclude extreme (nonphysiological) outliers of nutrient intakes, the extreme top and bottom 0.5% of the ratio of energy intake to estimated basal metabolic rate was used. RESULTS: The CAFE computer program modifies nutrient intake according to specific fats used in food preparation and the amount of visible fat on meat. It incorporates different breakfast cereals and distinguishes between text for brands and types. After exclusion of outliers of nutrient intake some extreme values remained for energy, carbohydrate, protein, fat and alcohol, because of high reported frequencies of certain foods. CONCLUSIONS: The features of CAFE include flexible, updateable, databases and a novel method for matching text. The effect of extreme nutrient values on the accuracy of the FFQ in estimating diet in nutritional epidemiology should be investigated further.     

Dietary sources of energy, protein, unavailable carbohydrate and fat in 11–12-year-old English children in 1990 compared with results in 1980

There is little information on the food intake of adolescents or on how the intake of adolescents has changed. Yet this information is essential to assess the effect of dietary health education and is valuable in formulating future advice. This paper reports the dietary sources of energy, protein, unavailable carbohydrate and fat in the diet of 379 11– and 12-year-old schoolchildren in 1990, and compares these data with similar information collected in 1980. Each child completed two 3-day dietary records between January and July, and was interviewed by one dietitian to verify and enlarge upon the information recorded to obtain a quantitative measure of food intake. The children attended the same seven middle schools in south Northumberland as 375 children of the same age who recorded their diet using the same method 10 years previously (Hackett et al., 1983). Food tables were used to calculate nutrient intake.
Although the total intakes of energy, protein, unavailable carbohydrate and fat changed little over the 10-year period, there were changes in the importance of food groups as contributors to total intakes. Notably, an increase in the role played by confectionery which became the second largest contributor to total energy intake and an increase in the importance of meat and its products as a source of energy, protein and fat. The proportion of energy, protein and fat being derived from milk decreased. Chips remained the largest single source of unavailable carbohydrate, and an important energy and fat source, while the role played by 'wholemeal' breads in unavailable carbohydrate intake had increased.     

Usefulness of a short food frequency questionnaire for screening of low intake of fruit and vegetable and for intake of fat

BACKGROUND: Simple screening tools to identify intake of fruit, vegetables and fat are necessary to design effective public health intervention strategies in order to increase intake of fruit and vegetable and to reduce fat intake. METHODS: 108 men recorded their food intake for 14 days and filled in a 27-item food frequency questionnaire (FFQ) 1.5-2 months later. Estimates of fruit, vegetables and fat intake from the FFQ were compared with those from the weighed records. RESULTS: Mean intake of vegetables and fruit estimated from the diet records increased with increasing categories for frequency of intake assessed by the FFQ. Spearman correlation coefficient between frequency of intake of vegetables and fruit from the FFQ and amount of these food items estimated from the weighed records was 0.46 and 0.66, respectively. The ability of the FFQ to predict those having inadequate intake of fruits and vegetables based on weighed record data, was more than 90%. Almost 95% who reported use of fat spreads by the FFQ also reported this by the records. The correlation coefficient between the amount of fat used on bread from the two methods was 0.79. The correlation between fat intake estimated from both methods was 0.36 and for saturated fat intake the correlation was 0.38. CONCLUSION: The FFQ could be used to screen for low consumers of fruit, vegetable and fat spread in intervention programmes. However, the ability of the FFQ to identify persons with high (or low) intake of fat and saturated fat was not good.     

Dietary assessment in Whitehall II: comparison of 7 d diet diary and food-frequency questionnaire and validity against biomarkers

The aim of the present cross-sectional study was to examine the agreement and disagreement between a 7 d diet diary (7DD) and a self-administered machine-readable food-frequency questionnaire (FFQ) asking about diet in the previous year, and to validate both methods with biomarkers of nutrient intake. The subjects were an age- and employment-grade-stratified random subsample of London-based civil servants (457 men and 403 women), aged 39-61 years, who completed both a 7DD and a FFQ at phase 3 follow-up (1991-1993) of the Whitehall II study. Mean daily intakes of dietary energy, total fat, saturated, monounsaturated and polyunsaturated fatty acids, linoleic acid, total carbohydrate excluding fibre, sugars, starch, dietary fibre, protein, vitamin C, vitamin E (as alpha-tocopherol equivalents), folate, carotenes (as total beta-carotene activity), Fe, Ca, Mg, K and alcohol were measured. Serum cholesteryl ester fatty acids (CEFA), plasma alpha-tocopherol and beta-carotene were also measured as biomarkers. Estimates of mean energy intake from the two methods were similar in men, and some 10 % higher according to the FFQ in women. Compared with the 7DD, the FFQ tended to overestimate plant-derived micronutrient intakes (carotenes from FFQ v. 7DD men 2713 (SD 1455) v. 2180 (SD 1188) microg/d, women 3100 (SD 1656) v. 2221 (SD 1180) microg/d, both differences P<0.0001) and to underestimate fat intake. Against plasma beta-carotene/cholesterol, carotene intake was as well estimated by the FFQ as the 7DD (Spearman rank correlations, men 0.32 v. 0.30, women 0.27 v. 0.22, all P< or =0.0001, energy-adjusted data). Ranking of participants by other nutrient intakes tended to be of the same order according to the two dietary methods, e.g. rank correlations for CEFA linoleic acid against FFQ and 7DD estimates respectively, men 0.38 v. 0.41, women 0.53 v. 0.62, all P< or =0.0001, energy-adjusted % fat). For alpha-tocopherol there were no correlations between plasma level and estimated intakes by either dietary method. Quartile agreement for energy-adjusted nutrient intakes between the two self-report methods was in the range 37-50 % for men and 32-44 % for women, and for alcohol, 57 % in both sexes. Disagreement (misclassification into extreme quartiles of intake) was in the range 0-6 % for both sexes. The dietary methods yielded similar prevalences (about 34 %) of low energy reporters. The two methods show satisfactory agreement, together with an expected level of systematic differences, in their estimates of nutrient intake. Against the available biomarkers, the machine-readable FFQ performed well in comparison with the manually coded 7DD in this study population. For both methods, regression-based adjustment of nutrient intake to mean dietary energy intake by gender appears on balance to be the optimal approach to data presentation and analysis, in view of the complex problem of low energy reporting.     

Trends in nutrient and dietary intake among adults and the elderly: from NAHSIT 1993-1996 to 2005-2008

The aim of this study was to investigate trends in nutrients and sources of dietary intake for Taiwanese people from the Nutrition and Health Survey in Taiwan (NAHSIT) 1993-1996 to 2005-2008. Twenty-four hour dietary recall data were obtained from the 2005-2008 NAHSIT. The results showed that intake of cereals and grains, and dietary fiber has decreased, whereas intake of carbohydrate rich convenience foods has increased. As a result, 10-20 g of dietary fat is now obtained from carbohydrate rich foods. A greater proportion of Taiwanese are choosing low-fat meat products, however, excessive intake of meat by men and women aged 19 to 64 years is resulting in excessive intakes of protein, cholesterol and saturated fat. Men and women aged 19 to 30 years had insufficient intakes of fruit and vegetables. Consumption of fruit, dairy/products, and nuts was low in all age groups. We recommend strengthening public nutrition education and changing diet related environment to improve dietary quality and food group distributions. Issues of concern include excessive intakes of energy and the soybean/fish/meat/eggs food group in all subjects, high amount of processed foods and refined-carbohydrate rich foods in men aged 19 to 64 years and women aged 19-30 years, as well as intakes below the DRI for a variety of nutrients in elderly persons.     

Sources of fiber and fat in diets of US women aged 19 to 50: implications for nutrition education and policy.

INTRODUCTION. Many women are not meeting dietary recommendations for fiber and fat intakes. Health educators need to know which foods are major sources of these nutrients. METHODS. This study analyzed the contributions of 27 food groups to fiber, fat, saturated fat, and cholesterol intakes of 2134 women aged 19 to 50 years in USDA's Continuing Survey of Food Intakes by Individuals, the 1985 and 1986 surveys (CSFII 85-86). RESULTS. Major determinants of fiber intake include frequency of use of certain food groups (vegetables, including potatoes, bread, fruit, soups, ready-to-eat cereal) and choice of particular foods within the larger food groups (e.g., whole grain bread, high fiber cereal). Major determinants of total fat, saturated fat, and cholesterol intakes included frequency of use of certain foods (sweet grains, beef, eggs, cheeses/cream, whole milks) and additions to foods (regular salad dressing and butter/margarine). Demographic characteristics were related to various food group consumption parameters. CONCLUSIONS. Information about the relationships between food group and nutrient intake and the effects of household income, race/ethnicity, and region of residence on food group intake indicate opportunities to refine nutritional education programs.     

葡萄糖调节受损患者膳食营养状况调查分析

目的 评价葡萄糖调节受损患者的膳食质量,为膳食干预提供理论依据.方法 从常规健康体检中选取符合空腹血糖受损(IFG)和/或糖耐量减低(IGT)的患者63例(统称为葡萄糖调节受损IGR),其中男性29例,女性34例,根据体质指数(BMI)分为正常体型组38例(BMI 21.0±1.11),超重体型组25例(BMI 26.6±0.95).采用食物频率问卷法和膳食史法相结合,分析患者的膳食能量、三大产热营养素摄入量及来源比例.结果 正常体型组能量、碳水化合物摄入量与标准供给量相比差异无统计学意义(P＜0.05),但其摄入量均超过标准供给量10％以上;蛋白质摄入量低于标准供给量10％,差异有统计学意义(P＜0.05);脂肪摄入量超过标准供给量10％,差异有统计学意义(P＜0.05).在营养素来源分配比例中,谷类食物、动物性蛋白质、动物性脂肪和植物性脂肪摄入量均超过标准供给量,差异有统计学意义(P＜0.05);非谷类食物和植物性蛋白质摄入量低于标准供给量,差异有统计学意义(P＜0.05).超重体型组能量、碳水化合物和脂肪摄入量均超过标准供给量,差异有统计学意义(P＜0.05).在营养素来源分配比例中,谷类食物、动物性脂肪和植物性脂肪摄入量均超过标准供给量,差异有统计学意义(P＜0.05);非谷类食物和植物性蛋白摄入量均低于标准供给量10％;动物性蛋白摄入量超过标准供给量10％.两组的胆固醇摄入量均高于300 mg/d,膳食纤维摄入量明显低于推荐剂量20～35 g/d.结论 糖调节受损患者膳食结构不合理,需要科学合理的营养干预.     

Development and evaluation of a semi-quantitative food frequency questionnaire for use in urban and rural India

The objective of this study was to develop and evaluate a semi-quantitative food frequency questionnaire (FFQ) for use in urban and rural India. A single FFQ was developed for use in cities and rural areas of four regions of India. To assess validity, the FFQ was administered to 530 factory workers and rural dwellers, and subsequently three 24 hour recalls were administered on different days. Nutrient and food group intake calculated from these two methods were compared using medians, kappa statistics, Spearman's correlation coefficients and Bland- Altman plots. Dietary intake was overestimated by the FFQ compared to the 24 hour recalls (mean difference in energy intake = 1743 kJ), with kappa statistics ranging from 0.07 (egg) to 0.51 (carbohydrate). The results showed acceptable validity for measuring intakes of groups, and demonstrated that it is feasible to measure dietary intake in diverse regions of India with a single FFQ.     

Impact of season of food frequency questionnaire administration on dietary reporting

PURPOSE: Foods consumed near the time of food frequency questionnaire (FFQ) administration may prime the memory, such that FFQ responses emphasize recently consumed foods. This study investigates the effect of season of FFQ administration, a proxy for the recent diet, on FFQ responses. METHODS: FFQ data from 74,958 Shanghai Women's Health Study (SWHS) subjects were compared with FFQ data from these subjects by season of FFQ administration (i.e., winter, spring, summer, and fall). All analyses were adjusted for age, BMI, and energy intake. Furthermore, quintile categories derived from all study subjects were compared with categories derived from the distribution of subjects recruited in the same season. RESULTS: Compared with the study group as a whole, subjects completing the FFQ in winter reported higher intakes of meat (2.1%), vegetable (3.9%), fish (3.1%), and soy foods (4.1%), but lower fruit (- 3.9%) intake. Subjects completing the FFQ in summer reported lower than average meat (- 2.0%), vegetable (- 3.2%), fish (- 2.3%), and soy food (- 4.6%) intakes, but greater fruit intake (0.9%). Completion of the FFQ in spring and fall usually led to intermediate differences from the group average, although fruit intake was 5.9% higher among subjects completing the FFQ in the fall. Variations across macronutrients and micronutrients by season of FFQ administration were smaller. If seasonal FFQ reporting is ignored, up to 13% of subjects would be classified to a different diet intake exposure category. However, reclassification was always to an adjacent category. CONCLUSIONS: FFQ responses varied with season of FFQ administration, consistent with theory that current diet intake influences reporting of habitual past diet intake. However, season of FFQ administration did not alter dietary exposure category assignments sufficiently to effect interpretation of most epidemiologic studies.     

The maximal amount of dietary alpha-tocopherol intake in U.S. adults (NHANES 2001-2002)

The current study was designed to determine the maximal amount of alpha-tocopherol intake obtained from food in the U.S. diet, and to examine the effect of different food group intakes on this amount. Data from 2138 men and 2213 women aged >18 y were obtained from the National Health and Nutrition Examination Survey (NHANES) 2001-2002. Linear programming was used to generate diets with maximal alpha-tocopherol intake, with the conditions of meeting the recommended daily allowances or adequate intakes for a set of nutrients, sodium and fat recommendations, and energy limits, and that were compatible with the observed dietary patterns in the population. With food use and energy constraints in models, diets formulated by linear programming provided 19.3-24.9 mg alpha-tocopherol for men and women aged 19-50 or >50 y. These amounts decreased to 15.4-19.9 mg with the addition of the sodium, dietary reference intake, and fat constraints. The relations between maximal alpha-tocopherol intake and food group intakes were influenced by total fat restrictions. Although meeting current recommendations (15 mg/d) appears feasible for individuals, dramatic dietary changes that include greater intakes of nuts and seeds, and fruit and vegetables, are needed. Careful selection of the highest vitamin E source foods within these groups could further increase the likelihood of meeting the current recommended daily allowance.