Relative validity of a food frequency questionnaire used to assess food intake during a dietary intervention study

To develop a cost-effective alternative for evaluating dietary intake in large-scale intervention trials of cancer and cardiovascular disease outcomes, we designed and validated a semiquantitative food frequency questionnaire (FFQ). We collected 6 to 8 of the 24-hr dietary recalls from 87 adults (ages 30-72 yr) who were randomly assigned to a walnut-supplemented diet or a control diet in a 6-mo dietary intervention trial. Relative validity of a 171-item FFQ in assessing intake of selected foods and the prescribed intervention (intake > or =25 g/day or intake < 2 g of walnuts) was determined using 24-h dietary recalls as the reference. De-attenuated correlations between FFQ and dietary recalls were .82 for walnuts, .80 for fruits, .79 for grains, .77 for vegetables, .63 for water, .44 for sweets, and .36 for dairy/eggs. High within-person variation did not allow de-attenuation for the remaining foods, but uncorrected correlations were high (> .7) for the beverage variables. The FFQ correctly classified 86 out of 87 subjects in the 2 prescribed intervention groups. The FFQ can provide an accurate measure of a food-based intervention (i.e., walnut supplementation) in a trial setting and can also accurately estimate a number of other food groups consumed during the trial.     

Validity and reliability of a quantitative food frequency questionnaire measuring n-3 fatty acid intakes in cardiac patients in the Midwest: a validation pilot study

The purpose of this pilot study was to test the validity and reliability of a quantitative n-3 fatty acid food frequency questionnaire (FFQ) for later use with larger groups of individuals. A convenience sample of heart patients provided dietary data via three 24-hour food recalls and FFQs. Participants were women (n=17) and men (n=11), 43 to 77 years of age. The association of mean daily intake of n-3 fatty acids obtained using food recalls and the FFQ was assessed by Pearson correlation. The reliability of the FFQ was assessed using coefficient alpha. Correlation of n-3 fatty acid intake using the food recalls and the FFQ was r=0.42 (P<0.05). The coefficient alpha for the test-retest of the FFQ was .83. The top two foods, walnuts and flaxseed, contributed 58% of the n-3 fatty acid intake, and the third food, salmon, contributed 5%. This quantitative n-3 FFQ is a valid instrument for use in place of food recalls for estimating n-3 fatty acid intakes in heart patients and is a reliable instrument to estimate n-3 fatty acid intakes from plant, animal, and seafood sources. The FFQ should be tested in a larger population. Registered dietitians can use this FFQ to screen for intakes, educate patients on food sources, and measure change in intakes after nutrition intervention.     

Relative Validity and Reproducibility of a Food Frequency Questionnaire to Assess Food Group Intake in Pregnant Jordanian Women

BackgroundResearch on the relationship between maternal diet and pregnancy outcomes requires valid dietary assessment tools in pregnancy.ObjectiveThis study aimed to develop and examine the relative validity and reproducibility of a quantitative food frequency questionnaire (FFQ) to estimate food group intake in a sample of pregnant Jordanian women.DesignIn this validation study, food group intake from a culturally sensitive quantitative FFQ was compared with food group intake from three 24-hour dietary recalls.Participants and settingThe validation study was conducted from 2015 to 2017 at the maternity clinics in Jordan University Hospital among 131 healthy singleton pregnant Jordanian women. Of these women, 30 also took part in the reproducibility phase, which involved repeated completion of the FFQ in a time frame of 1 month. Pregnant women who had gestational diabetes, preeclampsia, and chronic diseases were excluded.Main outcome measuresRelative validity and reproducibility of a 117-item quantitative FFQ used to estimate usual food intake over a period of 1 month.Statistical analyses performedIntraclass correlation coefficients and weighted κ statistics were calculated to test the reproducibility between the two administrations of the FFQ. Pearson correlations were estimated to validate the FFQ against 24-hour dietary recalls. Cross-classification and Bland-Altman plots were used to examine the agreement between the two dietary assessment methods.ResultsThe intraclass correlation coefficients between the two FFQs ranged from 0.24 for legumes to 0.93 for processed meats. A moderate level of agreement was observed between two FFQs. De-attenuated and energy-adjusted correlations ranged from 0.08 for sweets and sugar to 0.93 for sugary drinks. On average, 50.9% and 45.2% of participants were classified by the FFQ and the 24-hour dietary recalls into the same quartile based on their crude and energy-adjusted food group intake, respectively. Bland-Altman plots showed satisfactory agreement between two methods for most food groups.ConclusionsThe FFQ showed moderate reproducibility and good relative validity for most food groups.     

The food propensity questionnaire: concept, development, and validation for use as a covariate in a model to estimate usual food intake

OBJECTIVE: Twenty-four-hour recalls capture rich information on food consumption, but suffer from inadequately measuring usual intakes of episodically consumed foods. We explore using food frequency questionnaire (FFQ) data as covariates in a statistical model to estimate individual usual intakes of episodically consumed foods and their distributions and describe the development of the Food Propensity Questionnaire, an FFQ introduced in the 2003-2004 National Health and Nutrition Examination Survey. DESIGN: We analyzed data from 965 adult participants in the Eating at America's Table Study who completed four 24-hour recalls and an FFQ. We assessed whether or not increasing FFQ-reported frequency was associated with both number of 24-hour recall consumption days and amounts reported. RESULTS: For 52 of 56 food groups (93%), and 218 of 230 individual foods (95%), there were significant monotonically increasing relationships between FFQ frequency and 24-hour recall probability of consumption. For 47 of 56 food groups (84%) and 55 of 230 (24%) individual foods, there were significant positive correlations between FFQ frequencies and consumption-day mean intake. CONCLUSIONS: We found strong and consistent relationships between reported FFQ frequency of food and food-group consumption and probability of consumption on 24-hour recalls. This supports the premise that frequency data may offer important covariate information in supplementing multiple recalls for estimating usual intake of food groups.     

Validity and Calibration of Food Frequency Questionnaires Used with African-American Adults in the Jackson Heart Study

Objective

To examine the relative validity of two food frequency questionnaires (FFQs) developed for use in investigating diet and disease relationships within the adult African-American population in the southern United States.

Design

Cross-sectional analyses of dietary nutrient intake data, comparing four 24-hour dietary recalls with an FFQ developed by the Lower Mississippi Delta Nutrition Intervention Research Initiative, and its shorter version adapted for use in the Jackson Heart Study.

Subjects

A representative subset of participants (n=499, aged 35 to 81 years) from the baseline Jackson Heart Study cohort (N=5,302) was selected for this study. Data collection took place between winter 2000 and spring 2004.

Statistical analyses

Pearson's correlation coefficients (energy adjusted and de-attenuated) for 26 nutrients estimates from each of the FFQs, comparing them with the mean of four 24-hour dietary recalls. The ability of the FFQs to rank individuals based on nutrient intakes was compared to that of the mean of four 24-hour dietary recalls and attenuation coefficients were also calculated.

Results

Median nutrient intake estimates tended to be higher on the long and lower on the short FFQ compared to the median for the mean of four 24-hour dietary recalls. Energy adjusted and deattenuated correlations of FFQ intake estimates with recalls ranged from 0.20 for sodium to 0.70 for carbohydrate for the short FFQ and from 0.23 for polyunsaturated fat to 0.75 for dietary fiber and magnesium for the long. Attenuation coefficients for men on average were 0.42 for the short and 0.49 for the long FFQ. For women, these were 0.31 for the short and 0.42 for the long FFQ.

Conclusions

Both FFQs appear to be reasonably valid for assessment of dietary intake of adult African Americans in the South. The Lower Mississippi Delta Nutrition Intervention Research Initiative FFQ exhibited higher intake estimates and stronger correlations with recalls than the Jackson Heart Study FFQ for most nutrients analyzed, more so for women than men.     

Reliability and validity of a brief questionnaire to assess calcium intake of middle-school-aged children

OBJECTIVE: Evaluate the validity and reliability of a short (10-item) calcium food frequency questionnaire (FFQ) for use with middle-school-aged (11 to 14 years of age) children. DESIGN: The calcium FFQ was completed twice, with 1 week between administrations. Three 24-hour dietary recalls were collected from each participant after the second administration of the calcium FFQ. SUBJECTS/SETTING: Students in an ethnically diverse middle school in Minneapolis, MN (n=248). MAIN OUTCOME MEASURES: Calcium intake estimates from the calcium FFQ and dietary recalls. STATISTICAL ANALYSES: Correlations between calcium intake estimates from the first and second questionnaire administrations of the calcium FFQ were calculated and paired t tests were conducted to compare mean calcium intake estimates from each questionnaire administration. Mean intake estimates from the calcium FFQ and the dietary recalls were compared. Also, correlations between intake estimates from the calcium FFQ and the recalls were calculated. RESULTS: Correlation between calcium intake estimates derived from the first and second administration of the calcium FFQ was 0.74. Mean calcium intake estimates from the calcium FFQ and the average of the three dietary recalls were 856 mg/day and 993 mg/day, respectively (P<0.001). The correlation between calcium intake estimates derived from the calcium FFQ and the average of the recalls was 0.43. CONCLUSIONS: Reliability of the FFQ was found to be good while validity was weaker, with calcium intake from the calcium FFQ moderately associated with estimates from dietary recalls. Where a brief instrument for assessing calcium intake of middle-school-aged children is needed, the calcium FFQ evaluated in this study may be useful.     

Comparison of intakes of US Chinese women based on food frequency and 24-hour recall data

The objective of this cross-sectional study was to compare dietary reports from a food frequency questionnaire (FFQ) for US Chinese women with 24-hour recall estimates. The subjects were 56 women recruited through organizations in Philadelphia's Chinese community. Spearman correlations were used to describe FFQ estimates of food servings per month and nutrient intake per day vs estimates from three 24-hour recalls over 1 month. On average, women reported at least weekly consumption of 28 of 96 FFQ food items. The three most frequently consumed were rice (38 times/month), tea (29 times/month), and dark green, leafy vegetables (18 times/month). Comparing reported frequencies of the 28 foods to 24-hour recall estimates, the median Spearman correlation was 0.36. For nutrient estimates, correlations were high (r >0.5) for dietary fiber and calcium; moderate ( r =0.25 to 0.5) for energy, saturated fat, cholesterol, carbohydrates, protein, folic acid, and iron; but poor (r <0.25) for total fat, vitamin C, vitamin A, and carotene. These findings provide some assurance of the FFQ's adequacy for describing US Chinese women's intake of commonly consumed foods and selected nutrients. They also provide a basis for further improvements to, and evaluations of, the FFQ.     

Comparison of dietary assessment methods in a low-fat dietary intervention program

The food frequency questionnaire (FFQ) is commonly utilized for assessment of dietary fat intake, but its validity among individuals following a low-fat diet is unclear. We evaluated the agreement of nutrient estimates derived from FFQ, 24-h recall, and 3-day food records obtained from 104 participants in a randomized trial of a low-fat dietary intervention for women at elevated breast cancer risk. Comparisons were made for total calories, percent calories from fat, and total fat after 1 yr. Correlation was assessed using standard methods based on a null hypothesis of no agreement between instruments as well as by a methodology based on a null hypothesis that the instruments should be in agreement. With the use of standard methods, FFQ estimates for women on the low-fat diet were significantly correlated to records only for percent calories from fat (r = 0.39), whereas recall and record estimates were significantly correlated for all three dietary variables. Using the new method, we found no significant correlation between FFQ and either recalls or records for women following a low-fat diet but significant correlation between recall and record estimates for total calories (r = 0.67). Traditional correlation testing may overestimate the extent of agreement in dietary instruments among women on a low-fat diet. We found empirical support for the nontraditional method.     

Evaluation of the Validity of a Food Frequency Questionnaire and 24-Hour Dietary Recall to Assess Dietary Iron Intake in Children and Adolescents from the South American Youth/Child Cardiovascular and Environmental Study

BackgroundA food frequency questionnaire (FFQ) for South American children and adolescents was developed, but its validity for assessing dietary iron intake has not been evaluated.ObjectiveTo evaluate the validity of the FFQ and 24-hour dietary recalls (24h-DR) for assessing dietary iron intake in children and adolescents.DesignThe South American Youth/Child Cardiovascular and Environmental study is a multicenter observational study, conducted in five South American cities: Buenos Aires (Argentina), Lima (Peru), Medellin (Colombia), Sao Paulo, and Teresina (Brazil). The FFQ assessed dietary intake over the previous 3 months, and the 24h-DR was completed three times (2 weekdays and 1 weekend day) with a minimum 5-day interval between recalls. Blood samples were collected to assess serum iron, ferritin, and hemoglobin levels.Participants and settingData of 99 children (aged 3 to 10 years) and 50 adolescents (aged 11 to 17 years) from public and private schools were collected during 2015 to 2017.Main outcome measuresDietary iron intake calculated from the FFQ (using the sum of daily iron intake in all food/food groups) and 24h-DR (mean of 3 days using the multiple source method).Statistical analyses performedDietary iron intake in relation to blood biomarkers were assessed using Spearman rank correlations adjusted for sex, age, and total energy intake, and the quadratic weighted κ coefficients for agreement.ResultsSpearman correlations showed very good coefficients (range = 0.78 to 0.85) for the FFQ in both age groups; for the 24h-DR, the coefficients were weak in children and adolescents (range = 0.23 to 0.28). The agreement ranged from 59.9% to 72.9% for the FFQ and from 63.9% to 81.9% for the 24h-DR.ConclusionThe South American Youth/Child Cardiovascular and Environmental study FFQ exhibited good validity to rank total dietary iron intake in children and adolescents, and as well as the 24h-DR, presented good strength of agreements when compared with serum iron and ferritin levels.     

Validity and reproducibility of the food frequency questionnaire used in the Shanghai Women's Health Study

To evaluate the validity and reliability of the food frequency questionnaire (FFQ) used in the Shanghai Women's Health Study (SWHS), 200 SWHS participants were recruited for a dietary calibration study. Study participants completed an FFQ at baseline and 24-h dietary recalls (24-HDR) twice per month consecutively for 12 months. At the end of the study, a second FFQ was administered. Of the 200 study participants, 196 completed 24 or more days of 24-h dietary recalls, 191 completed two FFQs from whom the results of this report were based. The FFQ included the foods that accounted for 86% of the foods recorded in the 24-HDR surveys. Validity of the FFQ was evaluated by comparing intake levels of major nutrients and foods obtained from the second FFQ with those derived from the multiple 24-HDR. The median intake for major nutrients, rice, poultry and meat derived from the second FFQ and the 24-HDR was similar, with the differences ranging from 1.3 to 12.1%. The FFQ tended to overestimate the intake level of total vegetables and total fruits, and the differences were explained mainly by over-reporting seasonal vegetables and fruits consumption in the FFQ. Nutrient and food intake assessed by the FFQ and the multiple 24-HDR correlated very well, with the correlation coefficients being 0.59-0.66 for macronutrients, 0.41-0.59 for micronutrients, and 0.41-0.66 for major food groups. The reliability of the FFQ was assessed by comparing the correlation and median intake of nutrients and food groups obtained from the two FFQs that were administered approximately 2 y apart. The median intake levels for selected nutrients and food groups derived from the two FFQs were similar with differences below 10%. At the individual level, the intake levels of these dietary variables obtained from two FFQs also correlated well. When nutrient and food group intakes were categorized into quartiles, FFQ and 24-HDR produced exact agreement rates between 33 and 50%. Misclassification to adjacent quartile was common, ranging from 34-48%, while misclassification to an extreme quartile was rare (1-6%). These data indicate that the SWHS FFQ can reliably and accurately measure usual intake of major nutrients and food groups among women in Shanghai.     

Development and use of FFQ among adults in diverse settings across the globe

In nutritional epidemiology, development of valid dietary assessment instruments specific to populations in diverse settings is of paramount importance. Such instruments are essential when trying to characterise dietary patterns and intake, investigate diet-disease associations, inform and evaluate nutrition interventions, assess nutrient-gene interactions, conduct cross-country comparison studies and monitor nutrition transitions. The FFQ is a relatively inexpensive tool for measuring long-term dietary intake for large populations and for allowing researchers to track dietary changes over time. However, FFQ must be population specific to capture the local diet and available foods. Collecting 24-h dietary recalls and utilising community feedback to build the FFQ ensures that a culturally appropriate instrument is developed. This article presents several examples describing FFQ development and utilisation in different settings globally. In the Canadian Arctic, FFQ were developed and utilised to inform and evaluate a community-based intervention programme, characterise the diet and track dietary changes occurring among Inuit and Inuvialuit, populations experiencing rising rates of chronic disease and likely to be extremely vulnerable to the potential effects of climate change. Another example is an FFQ developed to assess sodium intake and evaluate a sodium reduction trial in a high-risk population in Barbados. An example is provided from Brazil, where an FFQ was developed to assess associations between diet, heterocyclic aromatic amines and colorectal adenoma among Japanese Brazilians and to conduct cross-country comparisons. These and other case studies highlight the diversity in dietary intake between populations and the need for FFQ to be developed to capture this diversity.     

Validation of a food frequency questionnaire in preschool children

BACKGROUND: Support for the validity of food frequency questionnaires (FFQ) in preschool children using parental report is limited. METHODS: We obtained dietary information for 68 children age 1-3 years using three or four 24-hour recalls and a FFQ regarding the child's diet covering one year from families in Denver, CO from 1997 to 1999. FFQs were completed by the parents, and recalls were collected via interviews with the parents and alternate caregivers, where applicable. Nutrient biomarkers were measured in the plasma of 38 of the children. All nutrients were adjusted for energy intake using residuals, and log-transformed where necessary. RESULTS: Correlations (Pearson r) between the FFQ and the average of the recalls were 0.33 for protein, 0.41 for carbohydrate, 0.39 for fat, 0.42 for vitamin C, 0.27 for alpha-tocopherol, and 0.08 for total energy intake. We found no substantial changes in these correlations after stratification by whether or not meals and snacks were provided by caregivers other than the parents. The highest correlations (Spearman r) with biological measures were 0.51 between plasma ascorbic acid and FFQ vitamin C, and 0.48 between plasma and FFQ alpha-tocopherol. CONCLUSIONS: The FFQ shows mostly good agreements with multiple 24-hour recalls and biomarkers in preschool children. In addition, the validity of the FFQ using parental report does not appear to be compromised when there are meal providers in addition to the parents.     

Reproducibility and relative validity of food group intake in a food frequency questionnaire developed for Nepalese diet

We developed a food frequency questionnaire (FFQ) designed to measure the dietary practices of adult Nepalese. The present study examined the validity and reproducibility of the FFQ. To evaluate the reproducibility of the FFQ, 116 subjects completed two 115-item FFQ across a four-month interval. Six 24-h dietary recalls were collected (1 each month) to assess the validity of the FFQ. Seven major food groups and 23 subgroups were clustered from the FFQ based on macronutrient composition. Spearman correlation coefficients evaluating reproducibility for all food groups were greater than 0.5, with the exceptions of oil. The correlations varied from 0.41 (oil) to 0.81 (vegetables). All crude spearman coefficients for validity were greater than 0.5 except for dairy products, pizzas/pastas and sausage/burgers. The FFQ was found to be reliable and valid for ranking the intake of food groups for Nepalese dietary intake.     

Food and Nutrient Displacement by Walnut Supplementation in a Randomized Crossover Study

The aim of this article is to evaluate the effect of a daily supplement of walnuts on the overall daily diet and nutrient profile of healthy adults. A randomized controlled trial with crossover design was conducted for two 6-month diet periods in southeast Californian communities. Subjects were randomized to receive a control diet or a walnut-supplemented diet, then switched. The walnut supplement represented approximately 12% of their daily energy intake. Trained nutritionists collected seven 24 h dietary recalls from each participant (a total of 14 recalls for both periods). Ninety participants were able to complete the study, including 50 females and 40 males. The average age of the participants was 54.3 years. Diets in the walnut period had significantly higher vegetable protein, total fat, total PUFA, PUFA 18:2, PUFA 22:6, and total dietary fiber (p < 0.05), while also exhibiting significantly lower PUFA 20:5. All mineral levels were higher on the walnut-supplemented diet. Calcium, phosphorus, magnesium, and zinc were, particularly, significantly higher among the walnut-supplemented group (p < 0.05). Displacement occurred in more than one-third of the entire nuts and seeds group; four-fifths of the non-alcoholic beverages and desserts groups; and the majority of the candy, sugar, and sweets group. Walnut supplementation can lead to favorable modifications in nutrient and food intake profiles that may contribute to chronic disease prevention. Nutrient and food displacement may be a mechanism to explain the favourable association between walnut intake and improved diet.     

Validity and systematic error in measuring carotenoid consumption with dietary self-report instruments

Vegetables and fruits are rich in carotenoids, a group of compounds thought to protect against cancer. Studies of diet-disease associations need valid and reliable instruments for measuring dietary intake. The authors present a measurement error model to estimate the validity (defined as correlation between self-reported intake and "true" intake), systematic error, and reliability of two self-report dietary assessment methods. Carotenoid exposure is measured by repeated 24-hour recalls, a food frequency questionnaire (FFQ), and a plasma marker. The model is applied to 1,013 participants assigned between 1995 and 2000 to the nonintervention arm of the Women's Healthy Eating and Living Study, a randomized trial assessing the impact of a low-fat, high-vegetable/fruit/fiber diet on preventing new breast cancer events. Diagnostics including graphs are used to assess the goodness of fit. The validity of the instruments was 0.44 for the 24-hour recalls and 0.39 for the FFQ. Systematic error accounted for over 22% and 50% of measurement error variance for the 24-hour recalls and FFQ, respectively. The use of either self-report method alone in diet-disease studies could lead to substantial bias and error. Multiple methods of dietary assessment may provide more accurate estimates of true dietary intake.     

Comparing biological measurements of vitamin C, folate, alpha-tocopherol and carotene with 24-hour dietary recall information in nonhispanic blacks and whites.

PURPOSE: To assess intake of several vitamins in preparation for a large cohort study investigating the effect of diet on risk of colon and prostate cancer. METHODS: The dietary intake of several vitamins were assessed using eight different 24-hour recalls and a 200-item food frequency questionnaire (FFQ) from each subject. Participants also attended a clinic where blood was drawn and body composition, weight, height, and blood pressure were measured. A total of 97 black and 96 nonhispanic white subjects participated. The levels of alpha-tocopherol, carotene, folate, and vitamin C in the blood were correlated with the dietary intakes as measured by both 24-hour recalls and FFQ. RESULTS: Correlations between blood levels and energy-adjusted dietary intake assessed by 24-hour recalls (with supplements) were as follows: carotene (adjusted for serum cholesterol): 0.47 and 0.55 in black and white subjects, respectively; alpha-tocopherol (adjusted for serum cholesterol): 0.61 (blacks) and 0.50 (whites); vitamin C: 0.22 (blacks) and 0.17 (whites); folate: 0.54 (blacks) and 0.55 (whites). Correlations between blood levels and FFQ indices were smaller in magnitude: 0.34 and 0.28 for carotene in black and white subjects, respectively, 0.37 and 0.56 for alpha-tocopherol (adjusted for serum cholesterol), 0.20 and 0.03 for vitamin C and 0.24 and 0.32 for folate. CONCLUSIONS: The correlations observed were generally of modest to moderate size and were similar to or larger than those reported by others. This is despite variations in absorption, metabolism, and excretion of the vitamins and suggests that both the 24-hour recalls and the FFQ contain valid information.     

Measuring dietary change in a diet intervention trial: comparing food frequency questionnaire and dietary recalls

Measurement of dietary change was assessed in a systematic quota subsample (n = 397) of women recruited into the Women's Healthy Eating and Living Study between 1996 and 1998, a multicenter, randomized dietary intervention trial among breast cancer survivors. Women from the intervention and comparison arms completed the Arizona Food Frequency Questionnaire (AFFQ) and 24-hour dietary recalls at baseline (prerandomization) and at year 1 (postrandomization). Both dietary measurement methods demonstrated significant changes in intake of key intervention-associated nutrients at year 1 in the intervention group subjects compared with minimal or no change in the comparison group subjects. The reliability of the AFFQ and recalls was measured in the comparison group and showed correlations of 0.63 and 0.43, respectively. Both instruments captured differences in dietary intake associated with the diet intervention. These results demonstrate the utility of using a multimode, multimethod approach (AFFQ and 24-hour dietary recalls) to measure differences in self-reported dietary intake over time as shown in this dietary intervention trial being conducted among breast cancer survivors.     

Comparison of adipose tissue fatty acids with dietary fatty acids as measured by 24-hour recall and food frequency questionnaire in Black and White Adventists: the Adventist Health Study

PURPOSE: To calibrate and compare intake of different fats and individual fatty acids as assessed with a food frequency questionnaire (FFQ) against that estimated with (i) a series of dietary recalls and; (ii) the relative fat concentration in an adipose tissue biopsy. The FFQ was specially designed for use in a cohort of Seventh-day Adventists. In preparation for a large cohort study investigating the effect of diet on risk of colon, prostate and breast cancer. METHODS: The association of adipose tissue fatty acids and dietary fat intake was assessed in 49 black and 72 white Seventh-day Adventists subjects using 8 different 24-hour recalls, a 200-item food frequency questionnaire (FFQ) and adipose tissue biopsies from each subject. RESULTS: Pearson correlation between fatty acids in adipose tissue and dietary intake as assessed by multiple 24-hour recalls were as follows: Linoleic acid: 0.77 in black and 0.71 in white subjects, respectively; Linolenic acid: 0.68 (blacks) and 0.62 (whites); Total Polyunsaturated fat (PUFA): 0.78 (blacks) and 0.70 (whites); Total Monounsaturated fat (MUFA): 0.35 (blacks) and 0.03 (whites); Total Saturated fat (SFA): 0.46 (blacks) and 0.56 (whites). Correlations between fatty acids in adipose tissue and dietary intake as assessed by FFQ were: Linoleic acid: 0.61 (blacks) and 0.52 (whites), respectively; Linolenic acid: 0.29 (blacks) and 0.49 (whites); PUFA: 0.62 (blacks) and 0.53 (whites); MUFA: 0.07 (blacks) and 0.31 (whites), SFA: 0.21 (blacks) and 0.31 (whites). CONCLUSIONS: Our study confirms findings of others that 24-hour recalls are valid for assessing dietary intake of different types of fat. The FFQ we developed and used in this study gave reasonably valid measures of fatty acid intake in our population and is thus suitable for use in large cohort studies. It had validity comparable to that observed for other FFQs.     

Feasibility and Acceptability of Dietary Intake Assessment Via 24-Hour Recall and Food Frequency Questionnaire among Women with Low Socioeconomic Status

Background

Comprehensive evaluation of dietary interventions depends on effective and efficient measurement to quantify behavior change. To date, little is known regarding which self-reported measure of dietary intake is most feasible and acceptable for use in evaluation of the effectiveness of diet intervention studies among underserved populations.

Validity of a Food Frequency Questionnaire in Assessing Nutrient Intakes of Low-Income Pregnant Women

Objective: In 1989, a validation study of eight nutrients was performed on a modified food frequency questionnaire (FFQ) specifically designed for low-income pregnant women. The purpose of this study was to broaden the scope of the previous study by assessing the validity of the FFQ for 17 additional nutrients. Methods: The Pregnancy Food Frequency Questionnaire (PFFQ) was administered to a sample of 295 low-income, pregnant women aged 14–43 years living in Massachusetts. A randomly selected subsample of 101 women who provided at least one diet recall and reported intake of less than 4,500 calories were included in this analysis. Results: Mean intake of 25 nutrients as assessed by one administration of the PFFQ and up to three diet recalls collected over 1 month were similar. Unadjusted correlation coefficients between nutrient intake measured by diet recalls and the questionnaire ranged from .28 (carotene) to .61 (folate). After adjusting for energy intake the correlations ranged from .03 (B12) to .46 (folate). The correlations corrected for day-to-day variation were higher, ranging from .07 (B12) to .90 (zinc). The mean correlation was .47 and there were 54% over .40. Conclusions: A food frequency questionnaire for English-speaking, low-income, pregnant women can provide maternal and child health practitioners and researchers a valid estimate of diet across a wide range of nutrients.