Validity of a food frequency questionnaire and a food diary in a short-term recall situation

The purpose of this study was to compare intakes of eight nutrients computed from a food frequency questionnaire (FFQ) and from 3-day food diaries with known values. Total food intake of 19 healthy adult volunteers (10 men and 9 women) was monitored for 2 weeks. Each week, subjects completed a 3-day diary and a 1-week FFQ. Subjects had previously completed one diary and one FFQ with respect to their usual diets. FFQs and diaries were analyzed for calories, protein, fat, cholesterol, calcium, iron, vitamin A, and vitamin C. All nutrients were underestimated by the FFQ (all p less than .05). Subjects omitted foods from the FFQ and incorrectly reported consumption frequencies. Vitamin A (p less than .001) and calories (p less than .05) were underestimated by the food diary. It is concluded that factors such as frequency of eating, pairing of foods, and explicitness of FFQ items affect recall accuracy. Those factors could influence the choice of FFQ design and administration.     

Determinants of long-term (24-year) diet recall ability using a 21-item food frequency questionnaire

This study sought to determine how well individuals are able to recall accurately their food habits of 24 years ago and identify those factors that are predictive of recall ability. We investigated the self-reported dietary intakes of 216 people, one-half of whom were vegetarians, including cancer cases and controls. We compared 21 key food items reported in 1960 with the same data reported in 1984. Recall ability was the highest for persons with stable diets. Vegetarian status, education, and church attendance were the other significant determinants of exact recall; age and church attendances were the only significant determinants of recall error. After excluding nonusers of particular foods, we found a positive correlation between frequency of use and recall ability.     

Validity and reproducibility of an adolescent web-based food frequency questionnaire

OBJECTIVE: To assess the validity and reproducibility of a newly developed, cost-effective, and easy to administer, Web-based food frequency questionnaire (FFQ) for the dietary assessment of adolescents. DESIGN: Cross-sectional validation of a Web-based FFQ, which contained 15 food groups (water; soft drinks, including fruit juice and diet soft drinks; alcoholic beverages; soup; milk and milk products; fruit; sweet and savory snacks/fillings; sauces and fat spreads; breakfast cereals; bread; cheese, fish/eggs/meat; pasta/rice; vegetables; and potatoes). Reference data for validation were 3-day estimated food records. Analyses were done for all participants and for consumers only (consumer in both Web-based FFQ and food record). SUBJECTS/SETTING: A selected group of adolescents (12 to 18 years of age, n=104) from participating secondary schools in Ghent, Belgium. RESULTS: For all participants, the measured intakes of water, fruit, breakfast cereals, fish/eggs/meat, pasta/rice, and potatoes were not significantly different between the two methods. The Spearman correlation for all foods was on average 0.38 (ranging from 0.20 for pasta/rice to 0.64 for breakfast cereals). When analyzed for consumers only, the Web-based FFQ showed significantly lower estimates for soft drinks, sweet and savory snacks/fillings, sauces and fat spreads, cheese, pasta/rice, and vegetables. The average Spearman correlation for all foods collectively was 0.30. When reproducibility of the Web-based FFQ was assessed, the average Spearman correlation coefficient for all foods collectively was 0.62. CONCLUSIONS: Most questions on the 15 food groups had acceptable reproducibility, whereas validation only showed reliable intakes for water, fruit, bread, and fish/eggs/meat. This Web-based FFQ could be a start for development of dietary assessment methods in public health nutrition contexts.     

Comparison of a food frequency questionnaire with a diet record

The associations between levels of nutrients derived from a 24-hour diet record and a food frequency questionnaire were assessed in a sample of 433 men and women. The food frequency questionnaire was administered three years after the completion of the diet record. Spearman correlations were all statistically significant; they varied from 0.36 for energy to 0.15 for vitamin A. Comparison of distributions into fifths showed few people grossly misclassified. A model was developed to assess the correlations which would be expected under various conditions of within and between subject variance for each nutrient, errors in measurements and drift in intake over time. The best possible correlation that could be obtained using the within and between subject variations in intake previously published, and with no measurement error or drift over time, was 0.60 for energy and 0.34 for vitamin A. Using a realistic measure of measurement error (standard deviation on log scale of 0.12 for diet record method, 0.06 for drift over time and 0.18 for food frequency method) the correlations obtained in the modelling were very similar to that observed. This study shows that it may be appropriate to use a food frequency questionnaire instead of a diet record to estimate intakes in population based epidemiological studies.     

Validity and reproducibility of a self-administered food frequency questionnaire in older people

This study assesses the validity and reproducibility of a 145-item self-administered food frequency questionnaire (FFQ) in a representative older population aged 63 to 80. Semi-quantitative FFQs were completed by 89% of 3,654 residents attending a community-based eye study in Sydney, Australia. The FFQ's validity was assessed against three, four-day weighed food records (WFRs) completed four months apart by 79 people. A further 152 subjects completed a repeat FFQ about a year after the baseline FFQ, of whom 131 completed a second repeat FFQ about six weeks later. Both short and long-term reproducibility of the FFQ were assessed using data from these subjects. Comparison of the FFQ with the average of the three, four-day weighed food records resulted in energy-adjusted Spearman correlations above 0.5 for most of the nutrients. The proportion of subjects correctly classified to within one quintile category for each nutrient intake ranged from 57% for zinc to 82% for vitamin C, with most nutrients correctly classified within one quintile for about 70% of subjects. Quadratic weighted kappas were reasonable, between 0.3 and 0.5 for most nutrients. The FFQ was highly reproducible in the short term, with correlations for most nutrients about 0.70 to 0.80 and acceptably reproducible in the longer term, with correlations mostly 0.60 to 0.70. The results verity that it is possible to use relatively simple, but comprehensive, self-administered FFQs to study nutrient exposures in large-scale epidemiological studies of the elderly and to expect reasonably high FFQ response rates.     

Validation of a self-administered diet history questionnaire using multiple diet records

The validity of a self-administered diet history questionnaire has been estimated using as the reference data the mean of three 4-day diet records collected over the year prior to the administration of the questionnaire, in 1985–1986. Subjects were women ages 45–70 years, participants in the Women's Health Trial Feasibility Study, a multi-center clinical trial in which some women were randomized to be taught to adopt and maintain a low-fat diet, while others maintained their usual diet. The questionnaire produced group mean nutrient estimates closely approximating the values obtained by three 4-day records, e.g. in the usual-diet group, 37.7% of calories from fat by both food records and by questionnaire, and in the low-fat, group, 21.3% of calories from fat by food records and 23.7% of calories from fat by questionnaire. Correlations between questionnaire and diet records for per cent of calories from fat were 0.67 and 0.65 respectively in the two groups; most correlations were in the 0.5–0.6 range, and were similar to those achievable by a single 4-day food record.     

The National Cancer Institute diet history questionnaire: validation of pyramid food servings

The performance of the National Cancer Institute's food frequency questionnaire, the Diet History Questionnaire (DHQ), in estimating servings of 30 US Department of Agriculture Food Guide Pyramid food groups was evaluated in the Eating at America's Table Study (1997-1998), a nationally representative sample of men and women aged 20-79 years. Participants who completed four nonconsecutive, telephone-administered 24-hour dietary recalls (n = 1,301) were mailed a DHQ; 965 respondents completed both the 24-hour dietary recalls and the DHQ. The US Department of Agriculture's Pyramid Servings Database was used to estimate intakes of pyramid servings for both diet assessment tools. The correlation (rho) between DHQ-reported intake and true intake and the attenuation factor (lambda) were estimated using a measurement error model with repeat 24-hour dietary recalls as the reference instrument. Correlations for energy-adjusted pyramid servings of foods ranged from 0.43 (other starchy vegetables) to 0.84 (milk) among women and from 0.42 (eggs) to 0.80 (total dairy food) among men. The mean rho and lambda after energy adjustment were 0.62 and 0.60 for women and 0.63 and 0.66 for men, respectively. This food frequency questionnaire validation study of foods measured in pyramid servings allowed for a measure of food intake consistent with national dietary guidance.     

乳腺癌患者豆类食品食用频率表的信度和效度研究

摘要:目的　对豆类食品食用频率表用于评估乳腺癌患者大豆异黄酮摄入量进行信度和效度研究。方法　以21 d为间隔,采用豆类食品食物频率表对253名正在接受化疗的乳腺癌患者进行两次膳食调查,比较两次结果之间的相关性,评价问卷的信度;以3日膳食记录法作为“标准”,记录乳腺癌患者进行下一化疗疗程前3 d的膳食情况,调查结果进行相关性分析,检测其效度。结果　信度研究中,各种豆类食品的大豆异黄酮以及大豆异黄酮的日均摄入总量均为正相关,相关系数为0.52～0.86,平均值0.69。效度研究中,豆类食品食用频率表与3 d膳食记录相比较,原始数据计算的相关系数为0.14～0.76,均值为0.48,将原始数据经对数转换后,相关系数均值为0.53。结论　豆类食品食用频率表具有较好的效度和信度,在研究乳腺癌患者大豆异黄酮摄入量与乳腺癌之间关系时,豆类食品食用频率表是一个较为理想的测量工具。     

Validity and reproducibility of food frequency questionnaire in Japanese children aged 6 years

The aim of the present study was to evaluate the validity and reproducibility of a food frequency questionnaire (FFQ) for use among young Japanese children. Forty-seven mothers of children aged 6 y completed two 3-d diet records and two FFQs over a 6-mo period. The FFQ asked the mothers how often, on average, their children consumed each of the 162 food items listed and what the usual serving size of each item was during the 6 mo prior to the study. Intakes of macro- and micronutrients were estimated by multiplying the frequency by the serving size for each food item. The validity of the FFQ was assessed by comparison of the two 3-d diet records. The reproducibility of the FFQ was based on the first and second FFQ administrations. The validity correlation ranged from 0.05 for α-tocopherol to 0.59 for retinol. The median correlation was 0.40. The reproducibility correlation was higher than 0.50 for all nutrients. For most nutrients, FFQ had acceptable reproducibility, whereas validity showed low to moderate correlations. Our FFQ could reasonably rank individuals according to dietary intake for epidemiologic studies, although the validity of the questionnaire is limited to specific nutrients.     

Validity and reproducibility of a food frequency questionnaire for pregnant Finnish women

The authors developed a self-administered 181-item food frequency questionnaire (FFQ) to assess dietary intake during pregnancy for Finnish women from August 1995 to July 1996. In the validation study (n = 113), the data that were collected by using two 5-day food records completed during the eighth month of pregnancy were compared with FFQ data. The intake of foods and nutrients was higher as determined by FFQ than that assessed using food records. Pearson correlation coefficients for nutrients, after adjustment for energy, ranged from 0.19 (vitamin E) to 0.70 (thiamin) and, for foods, from 0.03 (high-fat milk) to 0.84 (low-fat milk). Energy adjustment improved the correlations for nutrients. Correction for attenuation improved correlations for both foods and nutrients. On average, 70% of the foods and 69% of the nutrients fell into the same or adjacent quintiles, according to the FFQ and the food record. In the reproducibility study, 111 women completed the FFQs twice at a 1-month interval. The intraclass correlation coefficients for nutrients ranged from 0.42 (ethanol) to 0.72 (sucrose, riboflavin, and calcium), and for foods, they ranged from 0.44 (ice cream) to 0.91 (coffee). The authors conclude that the FFQ has an acceptable reproducibility and represents a useful tool for categorizing pregnant women according to their dietary intake.     

Long-term (24-year) recall reliability in cancer cases and controls using a 21-item food frequency questionnaire

The following two questions concerning diet recall were addressed when studying 117 incident cancer cases and 99 controls from the Adventist Mortality Study. Are recalls of past dietary habits reliable? Does recall ability differ between cancer cases and controls? Two sets of dietary data were compared using the American Cancer Society's food frequency questionnaire--as reported in 1960 and recalled in 1984. Ability to recall 21 key food items was evaluated both for individual foods and a combination of all foods by comparing recall scores. The comparison revealed that among food groups, 24-year recall ability varied greatly. There was no significant difference in recall ability between cancer incident cases and controls after controlling for factors that may be related to recall ability (e.g., age, education, and sex). Also, there was no significant difference in recall ability among subjects with or without other chronic diseases likely to affect diet pattern. The results revealed no significant differences in recall ability by sex and body mass index; however, significant differences by vegetarian status and diet stability were found. Significant differences by educational level were found only in univariate analysis.     

Validity of a food frequency questionnaire varied by age and body mass index

BACKGROUND AND OBJECTIVE: The validity of food frequency questionnaires (FFQs) in measuring food consumption and nutrient intake has to be assessed. The objective of this study was to assess the validity of a 128-item FFQ in specific subgroups of Finnish adults. METHODS: The study included 294 subjects (137 men and 157 women). A 3-day food record was used as the reference method. RESULTS: The mean intake of all nutrients except alcohol was higher measured with the FFQ than with the food records. In general, the Pearson correlations for energy adjusted nutrients between the FFQ and the food records were higher in women than in men. The correlations ranged from 0.14 (retinol) to 0.66 (fiber and alcohol) in men, and from 0.20 (long-chain n-3 fatty acids) to 0.70 (alcohol) in women. The results in subgroups showed that measuring nutrient intakes is more difficult among younger (30-50 years) women and overweight men and women than among others. CONCLUSIONS: The study showed that the FFQ is a useful tool in epidemiologic studies in measuring the diet of Finnish adults given that the problems among specific subgroups are taken into account in interpretation.     

Validation of a semi-quantitative food frequency questionnaire: comparison with a 1-year diet record

The validity of a self-administered semi-quantitative food frequency questionnaire was evaluated for a group of 27 men and women aged 20 to 54. Intakes of 18 nutrients computed from the questionnaire were compared with those derived from 1-year diet records completed approximately 18 months earlier. The questionnaire estimates of mean nutrient intake were within 10% of the mean diet record measurements for 11 of the 18 nutrients evaluated, and the difference was less than 25% for all but one nutrient (total vitamin A). Correlation coefficients comparing unadjusted nutrient intakes measured by the two methods ranged from 0.38 (vitamin C) to more than 0.65 (total calories, total fat, saturated fat, polyunsaturated fat, oleic acid, and cholesterol). The overall mean of correlation coefficients comparing intakes of the 18 nutrients measured by questionnaire and by diet record was 0.60. Coefficients for macronutrients decreased somewhat after adjustment for age and gender or caloric intake. The data provide further evidence that a simple and relatively inexpensive questionnaire can provide useful information on dietary intake over an extended period.     

Comparability of a short food frequency questionnaire to assess diet quality: the DISCOVER study

This study aims to assess comparability of a short food frequency questionnaire (SFFQ) used in the Determinants of Suicide: Conventional and Emergent Risk Study (DISCOVER Study) with a validated comprehensive FFQ (CFFQ). A total of 127 individuals completed SFFQ and CFFQ. Healthy eating was measured using Healthy Eating Score (HES). Estimated food intake and healthy eating assessed by SFFQ was compared with the CFFQ. For most food groups and HES, the highest Spearman’s rank correlation coefficients between the two FFQs were r?>?.60. For macro-nutrients, the correlations exceeded 0.4. Cross-classification of quantile analysis showed that participants were classified between 46% and 81% into the exact same quantiles, while 10% or less were misclassified into opposite quantiles. The Bland–Altman plots showed an acceptable level of agreement between the two dietary measurement methods. The SFFQ can be used for Canadian with psychiatric disorders to rank them based on their dietary intake.     

Validity of a self-administered food frequency questionnaire against 7-day dietary records in four seasons

The validity of a food frequency questionnaire (FFQ) was evaluated against four 7-d diet records among 23 men aged 27-70 y. Volunteer women recorded the amounts of all foods and beverages consumed by their husbands or fathers over a period of 7 d in four consecutive seasons in 1997 and 1998, and a self-administered FFQ was answered by each man after completion of the fourth diet record. The diet record was kept in accordance with the method used for Japan's National Nutrition Survey. The FFQ ascertained frequencies and amounts of consumption of rice, bread, noodles, green tea, and coffee: consumption frequency of 35 food items; and consumption frequency and amount of five alcoholic beverages. As for most nutrients and foods, mean intakes estimated by the FFQ were lower than those estimated from the diet record. Crude intake of nutrients showed fairly good agreement between the two methods in terms of Pearson's correlation coefficient (r > 0.5), except for total energy (r = 0.23), fat (r = 0.36), and vitamin A (r = 0.29). The adjustment for energy intake generally reduced the correlation; the reduction being fairly large for fat intake and vitamin A (r = 0.19 for both). There was generally good agreement for the intake of foods and beverages with exceptions for fats/oils (Spearman correlation coefficient, rs = 0.30) and other vegetables (rs = 0.35). The highest correlation was observed for alcoholic beverages (rs = 0.91), bread (rs = 0.80), and fruits (rs = 0.77). An FFQ covering a limited number of common foods may be useful in assessing the relative position of an individual's habitual consumption of foods and nutrients; however, the instrument generally underestimates absolute intake.