Misclassification of nutrient and energy intake from use of closed-ended questions in epidemiologic research

Development and Relative Validation of a Food Frequency Questionnaire to Assess Non-Nutritive Sweeteners Intake among Pregnant Women in Santiago, Chile: A Pilot Study

Studies on the effects of non-nutritive sweeteners (NNSs) among pregnant women are scarce and have produced mixed results. One of the major challenges is to accurately assess NNS intake, especially in countries that have implemented policies to prevent obesity and where many foods and beverages have been progressively reformulated to partially or totally replace sugar with NNSs. This study aimed to develop and assess the relative validity of a food frequency questionnaire (FFQ) for use in pregnant women. We developed an FFQ to examine the intake of seven NNSs (acesulfame-k, aspartame, cyclamate, saccharin, sucralose, steviol glycosides, and D-tagatose). This questionnaire was piloted in 29 pregnant women (median age = 31.2 y; 25th-75th percentile: 26.9-34.7) to assess NNS intake over the previous month, compared to 3-day dietary records (3-DR). The validity of this dietary method was assessed using Spearman's correlation coefficient, Lin´s concordance correlation coefficient (CCC), and Bland-Altman plots. Spearman's correlations between the FFQ on NNSs and 3-DR ranged from 0.50 for acesulfame K to 0.83 for saccharin. CCC ranged between 0.22 and 0.66. The Bland-Altman plots showed an overestimation of saccharin, sucralose, and steviol glycosides intake by the FFQ on NNSs compared with 3-DR, and an underestimation of acesulfame K and aspartame. Overall, the NNSs most frequently consumed were sucralose, and none of the participants exceeded the acceptable daily intake for any of the NNSs evaluated. The FFQ on NNSs seems to be reasonably valid in the assessment of NNSs among pregnant women.

Associations between adherence to Mediterranean dietary pattern and frequency, duration, and severity of migraine headache: A cross-sectional study

BACKGROUND

The present study was conducted to explore the association between adherence to Mediterranean dietary pattern and migraine headache features including frequency, duration, and severity, as well as patients' migraine-related disabilities among the Iranian population diagnosed with migraine.

METHODS

 In the present cross-sectional study on 262 migraine patients aged 20-50 years old, a validated 168-item, food frequency questionnaire was used to assess the dietary intakes of participants. The Mediterranean diet score was calculated for each subject using nine pre-defined dietary components and ranged from 0-9. The headache severity, duration, frequency, migraine headache index score (MHIS), and headache impact test-6 (HIT-6) were measured using related questionnaires.

RESULTS

 After controlling for potential confounders, Mediterranean diet tended to be associated with lower headache frequency (β = -1.74, 95% CI: -3.53,0.03) and duration (β = -0.28, 95% CI: -0.59, -0.02) and was significantly associated with lower MHIS (β = -29.32, 95% CI: -51.22, -7.42), and HIT-6 score (β = -2.86, 95% CI: -5.40, -0.32) for those in the highest category of Mediterranean diet scores compared to the lowest category. A subgroup analysis of women also revealed a negative association between Mediterranean diet and headaches frequency (β = -2.30, 95% CI: -4.27, -0.32), duration (β = -0.42, 95% CI: -0.78, -0.07), scores of MHIS (β = -47.44, 95% CI: -71.90, -22.99), and HIT-6 (β = -3.45, 95% CI: -6.29, -0.61), after controlling for potential confounders.

CONCLUSIONS

The present study suggests that adherence to the Mediterranean dietary pattern is associated with lower headache frequency, duration, MHIS, and HIT-6 score.

Meal occasion, overweight, obesity and central obesity in children and adults: a cross-sectional study based on a nationally representative survey. Colombia, 2015

OBJECTIVE

To establish the association of the number of meals/day with overweight (Ow), obesity (Ob) and central obesity (CO).

DESIGN

Cross-sectional, nationally representative surveys.

SETTING

Colombia.

PARTICIPANTS

A total of 6985 children aged 5-17 years and 7846 adults aged 18-64 years were included.

MAIN OUTCOMES AND MEASURES

According to the WHO, Ow was defined in children as a body mass index (BMI)-for-age Z-score between >1 and ≤2 and in adults as a BMI between ≥25 and <30 (kg/m²). Ob was defined as a Z-score >2 in children and as a BMI ≥30 in adults. CO in children was established by sex and age using cut-off points equivalent to those of adults established by the International Diabetes Federation: ≥90 and ≥80 cm in males and females, respectively. The number of meals/day was estimated with a Food Frequency Questionnaire. Meals/day were grouped into three categories: (reference ≤3, 4 and 5+ meals/day). Crude and adjusted relative prevalence ratios (PRs) and their 95% CIs were calculated. The adjustments included usual energy intake/day and physical activity.

RESULTS

In children, 18.5% had Ow, 6.7% had Ob and 4.0% had CO. The adjusted PRs for five or more meals/day versus three or fewer meals/day were 1.10 (95% CI 0.79 to 1.55) for Ow, 0.95 (95% CI 0.57 to 1.59) for Ob and 1.06 (95% CI 0.72 to 1.55) for CO. In adults, 32.3% had Ow, 13.1% had Ob and 44.8% had CO. The adjusted PRs for five or more meals/day versus three or fewer meals/day were 0.58 (95% CI 0.45 to 0.76) for Ow, 0.51 (95% CI 0.36 to 0.72) for Ob and 0.70 (95% CI 0.54 to 0.92) for CO.

CONCLUSIONS

In children, meals/day were not associated with Ow, Ob or CO. In adults, this inverse relationship exists regardless of energy intake/day, whether physical activity goals are met, sex, age and other potentially confounding sociodemographic and environmental variables.

The association of plant-based dietary patterns and psychological disorders among Iranian adults

BACKGROUND

Plant-based dietary pattern, a new scoring system, has had a favorable relationship with the risk of chronic diseases, however, the associations with mental health are long disputed. Thus, we examined the association between an overall plant-based diet (PDI), healthy plant-based diet (hPDI), and unhealthy plant-based diet (uPDI) and psychological disorders in adult Iranian patients.

METHODS

In this large cross-sectional study, 3,362 Iranian men and women were recruited. Dietary data were gathered using a validated and reliable Willett format food frequency questionnaire (FFQ). Plant-based dietary pattern scores were calculated based on the method of Satija et al. Psychological profile assessment was done using the validated hospital anxiety and depression scale (HADS) and the general health questionnaire (GHQ).

RESULTS

A total number of 943, 448, and 760 participants who suffered from depression, anxiety, and psychological distress, respectively, were identified. In the multivariable-adjusted analysis, participants in the highest category of PDI and hPDI scores had lower odds of having depression and anxiety than those in the lowest category. This association was also found between hPDI and psychological distress (OR: 0.51, 95% CI: 0.38-0.68). In contrast, higher scores of uPDI was associated with increased odds of anxiety (OR: 1.60, 95% CI: 1.06-2.42) and psychological distress (OR: 1.38, 95% CI: 1.01-1.90).

LIMITATION

The cross-sectional study design.

CONCLUSION

Our results indicated that greater adherence to the overall plant-based diet and healthy plant-based diet was inversely associated with psychological disorders, while following unhealthy plant-based diet increased the risk of anxiety and psychological distress.

The Association between Coffee Consumption Pattern and Prevalence of Metabolic Syndrome in Korean Adults

The inconsistent results of epidemiologic studies suggest that the health effects of coffee vary depending on coffee consumption pattern, such as the type and amount of coffee intake. This study investigated the association between coffee consumption and metabolic syndrome (MetS) in Korean adults. In total, coffee consumption patterns in 14,132 participants were assessed based on two-day, 24-h recall data. Multivariable logistic regression was used to examine the association between the type and daily servings of coffee and the prevalence of MetS. In women, the prevalence of MetS (odds ratio (OR) 0.82; 95% confidence interval (CI): 0.70, 0.96), elevated triglycerides (0.85; 0.75, 0.97), and reduced high-density lipoprotein (HDL)-cholesterol (HDL-C; 0.74; 0.66, 0.83) in 3-in-1 coffee consumers, as well as the prevalence of increased waist circumference (0.81; 0.68, 0.98) and reduced HDL-C (0.68; 0.59, 0.80) in black coffee consumers, were significantly lower compared to non-coffee consumers. Also, the inverse associations between total coffee intake, black coffee intake, and 3-in-1 coffee intake with MetS or components of MetS were more significant in individuals who consumed >1 versus ≤1 serving/day. In conclusion, coffee consumption (regardless of type) was associated with a reduced prevalence of MetS and its components in Korean women.

Association of Exposure to Artificial Light at Night While Sleeping With Risk of Obesity in Women

IMPORTANCE

Short sleep has been associated with obesity, but to date the association between exposure to artificial light at night (ALAN) while sleeping and obesity is unknown.

OBJECTIVE

To determine whether ALAN exposure while sleeping is associated with the prevalence and risk of obesity.

DESIGN, SETTING, AND PARTICIPANTS

This baseline and prospective analysis included women aged 35 to 74 years enrolled in the Sister Study in all 50 US states and Puerto Rico from July 2003 through March 2009. Follow-up was completed on August 14, 2015. A total of 43 722 women with no history of cancer or cardiovascular disease who were not shift workers, daytime sleepers, or pregnant at baseline were included in the analysis. Data were analyzed from September 1, 2017, through December 31, 2018.

EXPOSURES

Artificial light at night while sleeping reported at enrollment, categorized as no light, small nightlight in the room, light outside the room, and light or television in the room.

MAIN OUTCOMES AND MEASURES

Prevalent obesity at baseline was based on measured general obesity (body mass index [BMI] ≥30.0) and central obesity (waist circumference [WC] ≥88 cm, waist-to-hip ratio [WHR] ≥0.85, or waist-to-height ratio [WHtR]≥0.5). To evaluate incident overweight and obesity, self-reported BMI at enrollment was compared with self-reported BMI at follow-up (mean [SD] follow-up, 5.7 [1.0] years). Generalized log-linear models with robust error variance were used to estimate multivariable-adjusted prevalence ratios (PRs) and relative risks (RRs) with 95% CIs for prevalent and incident obesity.

RESULTS

Among the population of 43 722 women (mean [SD] age, 55.4 [8.9] years), having any ALAN exposure while sleeping was positively associated with a higher prevalence of obesity at baseline, as measured using BMI (PR, 1.03; 95% CI, 1.02-1.03), WC (PR, 1.12; 95% CI, 1.09-1.16), WHR (PR, 1.04; 95% CI, 1.00-1.08), and WHtR (PR, 1.07; 95% CI, 1.04-1.09), after adjusting for confounding factors, with P < .001 for trend for each measure. Having any ALAN exposure while sleeping was also associated with incident obesity (RR, 1.19; 95% CI, 1.06-1.34). Compared with no ALAN, sleeping with a television or a light on in the room was associated with gaining 5 kg or more (RR, 1.17; 95% CI, 1.08-1.27; P < .001 for trend), a BMI increase of 10% or more (RR, 1.13; 95% CI, 1.02-1.26; P = .04 for trend), incident overweight (RR, 1.22; 95% CI,1.06-1.40; P = .03 for trend), and incident obesity (RR, 1.33; 95% CI, 1.13-1.57; P < .001 for trend). Results were supported by sensitivity analyses and additional multivariable analyses including potential mediators such as sleep duration and quality, diet, and physical activity.

CONCLUSIONS AND RELEVANCE

These results suggest that exposure to ALAN while sleeping may be a risk factor for weight gain and development of overweight or obesity. Further prospective and interventional studies could help elucidate this association and clarify whether lowering exposure to ALAN while sleeping can promote obesity prevention.

Adherence to Mediterranean dietary pattern is inversely associated with depression, anxiety and psychological distress

Background: Few studies have assessed adherence to the Mediterranean diet in relation to psychological health, in particular in the Middle East.Objective: To examine the association between adherence to Mediterranean dietary pattern and prevalence of psychological disorders among a large population of Iranian adults.Design: In this cross-sectional study on 3172 Iranian adults aged 18-55 years, we used a validated food frequency questionnaire for the assessment of dietary intakes. Adherence to the Mediterranean dietary pattern was examined using the Trichopoulou et al. method. To assess psychological health, the Iranian validated version of the Hospital Anxiety and Depression Scale (HADS) was used. Psychological distress was assessed through the use of General Health Questionnaire (GHQ).Results: Mean age of study participants was 36.54 ± 4.97 years. After controlling for potential confounders, participants with the greatest adherence to the Mediterranean diet had lower odds for depression (OR: 0.60, 95% CI: 0.46-0.78), anxiety (OR: 0.61, 95% CI: 0.42-0.86) and psychological distress (OR: 0.60, 95% CI: 0.45-0.79) compared with those with the lowest adherence. When the association with components of Mediterranean diet was examined, we found that high intake of fruits and vegetables was associated with a lower odds of depression, anxiety and psychological distress. In contrast, high intake of grains was positively associated with depression, anxiety and psychological distress.Conclusion: We found evidence indicating an inverse association between adherence to Mediterranean dietary pattern and odds of psychological disorders including depression, anxiety and psychological distress.

Food and beverage consumption and food addiction among women in the Nurses' Health Studies

BACKGROUND AND AIMS

Previous studies have not addressed a fundamental component of a food addiction disorder: the compulsive relationship between eating and potentially positively reinforcing foods. We aimed to evaluate the association between food consumption and food addiction.

METHODS

We conducted cross-sectional analyses merging data from the Nurses' Health Study (n = 58,625) and Nurses' Health Study II (n = 65,063), two prospective cohort studies of female nurses in the United States. Diet was assessed in 2006-2007 using a food frequency questionnaire, and food addiction was assessed in 2008-2009 using the Modified Yale Food Addiction Scale.

RESULTS

The prevalence of food addiction was 5.4%. The odds of food addiction were strongest among nurses consuming 5+ servings/week (compared with <1 serving/month) of hamburgers (multivariable odds ratio (MVOR) 4.08; 95% CI, 2.66-6.25), French fries (MVOR, 2.37; 95% CI, 1.59-3.51) and pizza (MVOR, 2.49; 95% CI, 1.67-3.69). Consumption of red/processed meat, low/no fat snacks/desserts, and low calorie beverages was positively associated with food addiction, while consumption of refined grains, sugar-sweetened beverages and fruits, vegetables, and legumes was inversely associated with food addiction.

CONCLUSIONS

This epidemiologic study was the largest to examine food consumption and food addiction. Food addiction was positively associated with consumption of many hypothesized positively reinforcing foods that include a combination of carbohydrates and fats such as snacks, "fast foods," and candy bars. However, it was inversely or not associated with certain sweet foods, refined grains, and sugar-sweetened beverages, which is consistent with literature suggesting that carbohydrates (without other ingredients) are less associated with food addiction. Longitudinal analyses will help untangle the temporal order between food consumption and food addiction, as some relationships in our analyses were difficult to interpret due to the cross-sectional design.

Adherence to the DASH diet in relation to psychological profile of Iranian adults

INTRODUCTION

Although empirically derived dietary patterns have been examined in relation to depression, limited data are available linking theory-based dietary patterns and psychological health.

OBJECTIVE

We aimed to investigate the association between adherence to DASH-style diet and psychological health among Iranian adults.

METHODS

This cross-sectional study was done among 3846 general public adults in Isfahan, Iran. Dietary assessment was conducted using a validated 106-item dish-based semiquantitative food frequency questionnaire. To investigate participants' adherence to DASH-style diet, we created DASH score based on earlier publications focusing on eight components (fruits, vegetables, nuts and legumes, dairy products, grains, sweetened beverages and sweets, sodium, and red and processed meats). Participants were classified into three categories based on their DASH score [low (≤40), moderate (41-50), and high adherence (≥51)]. This categorization, instead of distribution-based classification, was used due to low adherence to the DASH dietary pattern in the study population. Psychological health was examined by means of validated Hospital Anxiety and Depression Scale and General Health Questionnaire. Depression, anxiety, and psychological distress were defined based on standard criteria.

RESULTS

We found that moderate adherence to DASH-style diet was associated with lower odds of depression (OR 0.73; 95 % CI 0.59-0.90, P _trend = 0.63) compared with those with the lowest adherence. In our stratified analyses, these associations remained significant for women (0.70; 0.54-0.91) and for normal-weight participants (0.70; 0.52-0.92). Moreover, after controlling for potential confounders, an inverse association was observed between high adherence to DASH-style diet and anxiety in normal-weight participants (0.61; 0.37-0.98). Such associations were also seen between moderate adherence to DASH-eating style and anxiety in overweight or obese individuals (0.63; 0.42-0.95). We failed to find any significant association between consumption of DASH-style diet and psychological distress.

CONCLUSION

We found an inverse association between moderate adherence to DASH dietary pattern and depression. Further prospective studies are required to confirm these findings.

Food-frequency questionnaires: a review of their design, validation and utilisation

A review of the literature concerning the design, utilisation and validation of food-frequency questionnaires (FFQ) has been carried out using a semi-systematic approach to obtaining, reviewing and extracting data from articles. Databases were searched from 1980 to 1999. The present review identified 227 validation (from 1980 to September 1999) and 164 utilisation (for 1998 only) studies. A number of design issues have been evaluated through the present review. These include: the need to consider how portion sizes have been described, self-defined giving higher mean correlations; how an FFQ was administered, interviewer-administered giving higher mean correlations for some nutrients; how many items to include on an FFQ, those with the largest number of items having higher correlations. Validation techniques were described. Most validation studies involved comparing an FFQ against another dietary assessment method; only 19 % compared an FFQ to a biomarker. Measurement differences were most commonly assessed by correlation coefficients as opposed to other more appropriate methods. Mean correlation coefficients were highest for Ca and fat, and lowest for vitamin A and vegetables. The utilisation studies showed that FFQ were most commonly used in cross-sectional surveys, with ninety-three of the FFQ being designed to be disease-specific. The present review results were presented to a group of experts and a consensus arrived at concerning the development, validation and use of FFQ. Recommendations derived from the consensus arising from the literature review are presented as an appendix to the present paper.

Validity and reliability of the Block98 food-frequency questionnaire in a sample of Canadian women

Objective

To assess the validity and reliability of the most recent adaptation of Block's full-diet food-frequency questionnaire (FFQ) among a sample of Canadian women.

Design

Participants completed a self-administered FFQ (FFQ1), two unannounced 24-hour recalls (weekday and weekend) and a second FFQ (FFQ2) between October 2003 and February 2004. FFQs and recalls were analysed for 32 nutrients using Block Dietary Data Systems and the University of Minnesota's Nutrient Data System. Mean and median intakes were computed, along with crude and deattenuated Pearson correlation coefficients between FFQ1 and the average of two recalls (validity) and between FFQ1 and FFQ2 (reliability).

Setting

Ontario, Canada.

Subjects

A random population-based sample (n = 166) of women aged 25 to 74 years.

Results

One hundred and fifteen (69%) women completed FFQ1, 96 completed FFQ1 and both recalls, and 93 completed both FFQs, about 56 days apart. Mean intakes were similar for most nutrients. FFQ reliability was high, with Pearson correlation coefficients having a median of 0.75, ranging from 0.57 to 0.90 (macronutrients) and from 0.65 to 0.88 (micronutrients from supplements and food). FFQ validity was moderate to high, with deattenuated Pearson correlation coefficients having a median of 0.59, ranging from 0.11 to 0.73 (macronutrients) and from 0.50 to 0.76 (micronutrients from supplements and food). Our micronutrient correlations were similar to or higher than those of other studies that included supplements. Two correlations <0.40 were associated with fats.

Conclusions

The validity and reliability of this full-diet version of the Block FFQ were moderate to high, supporting its use in future studies among Canadian women.

Validity and reproducibility of a computerised tool for assessing the iron, calcium and vitamin C intake of Belgian women

OBJECTIVE

To determine the relative validity of a newly developed iron intake assessment tool, designed specifically to assess iron, calcium and vitamin C intake.

DESIGN

Estimates of iron, calcium and vitamin C intake from a computerised iron intake assessment tool compared with those from 11-day estimated dietary records.

SETTING

Region of Ghent (N= +/- 225,000), a city in Flanders, the Dutch-speaking part of Belgium.

SUBJECTS

In all, 50 women aged 18-39 y, participating in a large-scale epidemiological study on iron intake and iron status.

MAIN RESULTS

Mean dietary iron intake from the 11-day food record, the unadjusted dietary iron intake assessment tool and the adjusted tool was, respectively, 10.5 +/- 2.7, 10.4 +/- 4.3 and 9.6 +/- 2.9 mg. For the different nutrients, the correlation coefficients vary from 0.45 to 0.60 for adjusted intake. The mean difference of iron intake by the two methods (0.8 +/- 2.9 mg) did not differ significantly from zero. The new method correctly classified 38% (iron), 38% (calcium) and 58% (vitamin C) of the subjects to the correct tertile. The correlation coefficients ranged from 0.48 for adjusted vitamin C intake to 0.73 for adjusted calcium intake between two administrations.

CONCLUSION

The newly developed instrument can be used to assess mean group intakes of iron, calcium and vitamin C in women consuming a Western diet. However, since the ranking capability of the new tool is rather weak, further refinement of the tool is required to produce a robust method for assessing iron, calcium and vitamin C intakes of individuals.

SPONSORSHIP

This research was supported by the Belgian National Fund for Scientific Research/Flemish Division (Fund No G.0152.01).

Predictors of postmenopausal body mass index and waist hip ratio in the oklahoma postmenopausal health disparities study

OBJECTIVE

The goal of the current study has been to examine systematically the respective roles of nutrition, exercise, menopausal weight gain, moderate drinking and smoking as determinants of body mass index (BMI) and waist hip ratio (WHR) in a setting in which the role of race or ethnic group could be simultaneously or individually evaluated as predictors of BMI and WHR. Because the use of estrogen replacement has been reported to affect estimates of body fat mass in postmenopausal women, endocrine factors have also been evaluated.

METHODS

The design is cross-sectional with historical prospective elements. The study has a biomedical focus and is not an epidemiologic study. Data are from 649 women recruited into The Postmenopausal Health Disparities Study in Oklahoma. The study population was composed of 649 postmenopausal women: American Indian: 226 (34.9%), Asian: 21 (3.2%), Black: 78 (12.0%), Hispanics: 54 (8.3%) and Whites: 270 (41.6%). Recruitment occurred between 1994 and late 1999 in Oklahoma.

RESULTS

In this multi-racial, multi-ethnic study population, there was statistical heterogeneity in all nutrition/dietary and exercise variables as well as in other potential determinants of BMI and WHR. In contrast to the literature available for postmenopausal women in which postmenopausal status, estrogen replacement and race have rarely been taken into account, the results of multi-linear regression revealed the following: Significant predictors for BMI, with or without WHR specified, included the neuroendocrine factors, menopausal weight gain, smoking, mean fitness (i.e., difficulty performing physical activities), fat as percent of total calories, moderate drinking and being Asian or Black. When WHR was not included, total calories and socioeconomic status also entered the model. The statistical predictors of WHR in the total study population with BMI in the equation included BMI and the neuroendocrine variables of FSH, E2, but not ERT, as well as the interaction of higher intensity exercise fitness with frequency, socioeconomic status and being American Indian or Asian. When BMI was not included in the model, in addition to the neuroendocrine factors, the interaction of lower intensity exercise fitness with frequency, fat as percent of total calories, age living alone and being American Indian or and Black were significant predictors of WHR. The predictors of both BMI and WHR were found to differ among individual racial and ethnic groups.

CONCLUSIONS

Given the role of increased body fat and obesity in disease risk and the substantial differences in life expectancy among the racial and ethnic groups, the findings of this study, particularly in contrast to literature reports, strongly suggest that a whole variety of factors including hormonal status and race need to be considered when examining the role of dietary factors and physical activity in relation to estimates of body fat mass and disease risk.

Development, validation and utilisation of food-frequency questionnaires - a review

OBJECTIVE

The purpose of this review is to provide guidance on the development, validation and use of food-frequency questionnaires (FFQs) for different study designs. It does not include any recommendations about the most appropriate method for dietary assessment (e.g. food-frequency questionnaire versus weighed record).

METHODS

A comprehensive search of electronic databases was carried out for publications from 1980 to 1999. Findings from the review were then commented upon and added to by a group of international experts.

RESULTS

Recommendations have been developed to aid in the design, validation and use of FFQs. Specific details of each of these areas are discussed in the text.

CONCLUSIONS

FFQs are being used in a variety of ways and different study designs. There is no gold standard for directly assessing the validity of FFQs. Nevertheless, the outcome of this review should help those wishing to develop or adapt an FFQ to validate it for its intended use.

Validity of nutrient estimates by food frequency questionnaires based either on exact frequencies or categories

PURPOSE

The study was designed to assess if category-based Food Frequency Questionnaires (FFQ) could be substituted for exact-frequency based questionnaires.

METHODS

Nutrient estimates on 203 subjects from Toronto, Canada, derived from recoding an exact frequency based 132 item food frequency questionnaire (E-FFQ) into categories were evaluated for validity against a 7-day food record (FR).

RESULTS

Among men, the median Pearson's correlation coefficient (for energy adjusted nutrients) between FR and E-FFQ was 0.53, ranging from 0.26 for thiamin to 0.72 for calcium. The median correlation dropped to a value of 0.40 (range: 0.18 for thiamin to 0. 56 for carbohydrate) when a category-based FFQ (C-FFQ) and FR were compared. Data on women showed a similar pattern; a median correlation of 0.50 from E-FFQ and 0.42 from C-FFQ.

CONCLUSIONS

While the results varied with individual nutrients, overall it is concluded that when validated against food records, the use of exact frequencies in FFQs yielded higher correlation coefficients for most nutrients, and slightly better agreement within quartiles of categories than recoded frequency categories.

Comparability of nutrient estimation by three food frequency questionnaires for use in epidemiological studies

Replication of results is an important issue in studies of diet and disease, possibly dependent on data collection method. We compared assessments from the Health Habits and History Questionnaire (HHHQ), the Harvard Semiquantitative Food Frequency Questionnaire (HFFQ), and the New York State Cohort Food Frequency Questionnaire (CFFQ) for estimates of daily intakes of energy, protein, carbohydrates, total fat, dietary fiber, cholesterol, vitamins A, C, and E, and carotenoids. Fifty-nine men and 50 women aged 35-73 years completed the HHHQ and HFFQ as interviews and the 44-food CFFQ as a self-administered mailed questionnaire. Comparability was assessed with Spearman correlation coefficients. Quantitation of nutrient intake differed by nutrient, questionnaire, and nutrient calculation method. Ranking on energy and macronutrient intake for the HHHQ and HFFQ ranged from 0.62 to 0.80; ranking for micronutrient intake ranged from 0.56 to 0.80. For the CFFQ with the HHHQ or HFFQ, correlations ranged between 0.29 and 0.62. The CFFQ performs comparably to the HHHQ and HFFQ for some, but not all, nutrients; our results suggest that the HHHQ and HFFQ can be used interchangeably with reasonable confidence in studies of diet and disease.

[Development of a quantitative questionnaire of food intake in japanese immigrants and their descendants residents in Sao Paulo, Brazil]

The present study describes the development of a questionnaire to assess usual frequency and quantity of food and nutrient intake by people of Japanese descent living in São Paulo, Brazil. Both the food list and appropriate serving sizes for food items from the Food Frequency Questionnaire (FFQ) were selected from a cross-sectional assessment of diet in a random sample of Japanese immigrants living in the city of São Paulo (first- and second-generations, n = 166), aged 45-70 years, using self-administered three-day food records. We used the food records to select food items on the basis of their contribution to total population intake of relevant foods and nutrients. Criteria for grouping separate foods included similarity in nutrient content per usual serving and the importance of a particular food (e.g., typical Japanese foods). Four portion sizes were presented: small, medium, large, and extra-large. We examined the frequency distribution of equivalent-gram weights of each selected food and identified the four serving sizes in the distribution. The quantitative FFQ was designed with 129 food groups and exact frequencies of intake. Instructions for self-reporting and applications of the method for epidemiological use are discussed.

Estimated intakes of trans fatty and other fatty acids in the US population

OBJECTIVE

To estimate mean level of trans fatty acid intakes using a representative sample of the US population.

DESIGN

The study used food intake data from the 1989-1991 Continuing Survey of Food Intakes by Individuals (CSFII) and the trans fatty acid contents of specific foods calculated from a database compiled by the US Department of Agriculture (USDA) to estimate the mean level and deciles of trans fatty acid intake of the representative US population.

SUBJECTS/SETTING

Trans fatty acid intakes were estimated for each subject (N = 11,258) in the CSFII data who completed both a 24-hour recall and a 2-day food record.

STATISTICAL ANALYSES PERFORMED

Weights developed by USDA for the survey were used for all data analyses. The Technical Assessment Systems (TAS) International Diet Research System (TAS-DIET), software developed by TAS, was used to derive weighted estimates of the mean and percentiles of the intake distribution. PC CARP, software designed by Iowa State University, was used to estimate standard errors.

RESULTS

Mean percentage of energy ingested as trans fatty acids was 2.6% and the mean percentage of total fat ingested as trans fatty acids was 7.4%. Across all age and gender groups examined, estimates ranged from 2.6% to 2.8% and 7.1% to 7.9%, respectively.

APPLICATIONS/CONCLUSIONS

Dietetics practitioners can use the representative data of this study to help clients achieve desired changes in consumption levels of trans fatty acids.

Sucrose as a risk factor for cancer of the colon and rectum: a case-control study in Uruguay

In order to examine the relationship between dietary sucrose intake and colorectal cancer, a case-control study was conducted in Uruguay in the time period 1992-1996. In all, 289 cases and 564 controls, admitted for diagnosis or treatment in the 4 major hospitals in Montevideo, were considered eligible for the study. Total sucrose intake was associated with a monotonic positive gradient of risks and the odds ratio (OR) for the uppermost quartile of intake was of 2.18 (95% confidence interval, CI, 1.35-3.51). Glucose intake was associated with a small and non-significant increase in risk (OR 1.46, 95% CI 0.76-2.82). Finally, an interaction between sucrose and protein intake was found, and the OR for high intakes of sucrose and protein was 6.07.

Dietary fiber and risk of breast cancer: a case-control study in Uruguay

To examine whether dietary fiber modifies breast cancer risk, a case-control study involving 351 newly diagnosed patients with breast cancer and 356 hospitalized controls was conducted in Uruguay. Dietary patterns were assessed in detail by use of a food frequency questionnaire on 64 items, which allowed the calculation of total energy intake. Nutrient residuals were calculated through regression analysis. After adjustment for potential confounders (which included age, residence, family history of breast cancer, prior history of benign breast disease, parity, total energy, red meat, lutein/zeaxanthin and quercetin intake, and menopausal status), dietary fiber and total nonstarch polysaccharides were associated with a strong reduction in risk of breast cancer (odds ratio for uppermost quartile of total dietary fiber = 0.51, 95% confidence limit = 0.31-0.82). Also the dose-response pattern was highly significant (p < 0.001). The inverse association was observed in pre- and post-menopausal women and was similar for soluble and insoluble fiber. Furthermore, dietary fiber displayed a strong joint effect with fat, quercetin, and lutein/zeaxanthin.

Meat consumption and risk of lung cancer; a case-control study from Uruguay

A case-control study was conducted at the Instituto Nacional de Oncologia, Uruguay, in order to investigate the relationship between meat consumption and lung cancer risk. The study included 256 cases of lung cancer and 284 controls, frequency matched with the cases on age, residence and urban/rural condition. A significant increase in risk of lung cancer associated with red meat, beef and fried meat was observed. The increase in risk was more evident in squamous cell lung cancer. This association remained after controlling for total energy and saturated fat intake, suggesting a possible role of heterocyclic amines in lung carcinogenesis.