Markers for the Validation of Reported Dietary Intake in Adults with Cystic Fibrosis

Objective

To identify different markers in order to validate the assessment of dietary intake in adults with cystic fibrosis (CF).

Design

Cross-sectional survey.

Setting

Tertiary care.

Subjects

We assessed 37 adults with CF whose nutritional and respiratory condition was stable and 37 healthy adults, matched for age, sex, and nutritional status.

Interventions

A consecutive, 7-day, prospective dietary survey was given to all the participants. Anthropometric variables were measured and a fasting blood sample was drawn to measure the composition of the serum phospholipid fatty acids by gas chromatography. We also measured fecal fat and nitrogen at 72 hours and 24-hour urine nitrogen.

Results

The ratio of energy intake to basal metabolic rate expenditure was significantly greater in the patients (2.1±0.4) than the controls (1.79±0.4) and the percentage of patients with the ratio of energy intake to basal metabolic rate lower than 1.55 was 24% in the controls (n=9) vs 8% in the patients (n=3). Fecal nitrogen correlated significantly with total energy and the intake of carbohydrates, lipids, and proteins. In the patients, total dietary energy and fat and protein intake correlated positively with fecal fat. The protein and fat intake and fecal nitrogen and fat correlated significantly with urine nitrogen. In the controls, significant correlations were seen between different parameters of intake and the percentage of certain serum phospholipid fatty acids. These correlations in the patients were either absent or less marked.

Conclusions

Use in persons with CF of the energy intake to basal metabolic rate ratio, measurement of fecal fat and nitrogen at 72 hours and of urine nitrogen may be useful to validate dietary surveys. The serum phospholipid fatty acid profile, however, may be less useful for this purpose in these patients.     

Beneficial effects of fructo-oligosaccharides supplementation on fecal bifidobacteria and index of peroxidation status in constipated nursing-home residents—A placebo-controlled, diet-controlled trial

Objective

This study assessed effects of fructo-oligosaccharides (FOS) supplementation on fecal bifidobacteria, lipid peroxidation index, indices of nutritional status, and whether effects of FOS were sustained after its withdrawal in constipated nursing-home residents. The associations of fecal bifidobacteria and blood measurements were also examined.

Methods

Six men and four women participated in a double-blind, diet-controlled study that consisted of a 4-wk placebo (3 mL of fructose syrup) period, a 4-wk FOS (10 g/d) period, and a 4-wk post-FOS period. Stools were collected during the last week of each period to determine the microflora and fecal weight. Fasting blood was collected at the end of each period and analyzed for thiobarbituric acid-reactive substances (TBARS) and biochemical indices.

Results

Fecal counts (log counts/gram of dry feces) and daily fecal output of bifidobacteria significantly increased with FOS compared with placebo. The effect on bifidobacteria output was sustained in the post-FOS period. Plasma TBARS concentration was reduced by 16% and 21% in the FOS and post-FOS periods, respectively, compared with that in the placebo period. The plasma cholesterol level was significantly lowered by 7% in the FOS and post-FOS periods compared with that in the placebo period. The increases in fecal bifidobacteria output during the FOS period (log colony-forming units per day) were associated with decreases in plasma TBARS and plasma cholesterol, respectively.

Conclusion

Supplementation of FOS increases the daily output of bifidobacteria and decreases plasma TBARS and cholesterol concentrations in constipated nursing-home elderly residents and these effects remained at the end the post-FOS period.     

Effect of micellar lipids, dietary fiber and β-carotene on lutein bioavailability in aged rats with lutein deficiency

Objective

To determine the effect of various dietary components on the intestinal uptake of lutein in aged rats.

Methods

This study determined the time-course (2, 4, 6, 8 h) plasma and tissue responses of a pharmacologic dose of lutein (200 μM) solubilized in mixed micelles with fat (3%, soybean oil), phosphatidylcholine (PC; 3 mM), lysophosphatidylcholine (lysoPC; 3 mM), dietary fiber (pectin, 1.25%), β-carotene (200 μM), or micelles with no dietary components (control) in aged rats with lutein deficiency.

Results

No lutein was detected in the plasma of rats at 0 h indicating the deficiency. After gavages of lutein, the mean percent area under the curve (picomoles per milliliter per 8 h) of plasma lutein in the fat (91.4), PC (218.0), and lysoPC (94.1) groups were higher (P > 0.05), whereas its level in the dietary fiber and β-carotene groups was lower than the control group. The liver and eye lutein levels of the PC (95.4, 38.67%) and fat (18.2, 143%) groups were significantly higher, whereas the lysoPC (9.6, 27.2%), β-carotene (19.2, 35.4%), and dietary fiber (3.1, 88.4%) groups were lower than the control group.

Conclusion

Results indicate that soybean oil and soy phospholipids greatly sway lutein absorption in aged rats with lutein deficiency. The results also suggest that ingestion of lutein with pectin and β-carotene suppresses lutein absorption. Hence, to improve the absorption of lutein in older adults with macular pigment deficiency, foods with sufficient fat with low dietary fiber and β-carotene may be suggested.     

Carbohydrate Intake and Overweight and Obesity among Healthy Adults

Background

Little is known about the dietary habits of people with optimal body weight in communities with high overweight and obesity prevalence.

Objective

To evaluate carbohydrate intake in relation to overweight and obesity in healthy, free-living adults.

Design

We used a cross-sectional analysis.

Subjects/setting

The Canadian Community Health Survey Cycle 2.2 is a cross-sectional survey of Canadians conducted in 2004-2005. There were 4,451 participants aged 18 years and older with anthropometric and dietary data and no comorbid conditions in this analysis.

Main outcome measures

Outcome variables were body mass index (BMI; calculated as kg/m²) and overweight or obesity status (dichotomous) defined as BMI ≥25 compared with BMI <25 based on measured height and weight. Diet was evaluated by 24-hour dietary recall based on the Automated Multi-Pass Method.

Statistical analyses performed

Weighted regression models with bootstrapping and cubic splines were used. Outcome variables were BMI and overweight or obesity, and predictors were daily nutrient intake. Adjustment for total energy intake, age, leisure time energy expenditure, sex, smoking, education, and income adequacy was performed.

Results

Risk of overweight and obesity was decreased in all quartiles of carbohydrate intake compared to the lowest intake category (multivariate odds ratio quartile 2=0.63; 95% confidence interval: 0.49 to 0.90; odds ratio quartile 3=0.58; 95% confidence interval: 0.41 to 0.82; odds ratio quartile 4=0.60; 95% confidence interval: 0.42 to 0.85). Spline analyses revealed lowest risk among those consuming 290 to 310 g/day carbohydrates.

Conclusions

Consuming a low-carbohydrate (approximately <47% energy) diet is associated with greater likelihood of being overweight or obese among healthy, free-living adults. Lowest risk may be obtained by consuming 47% to 64% energy from carbohydrates.     

Contribution of dietary supplements to nutrient adequacy among children in Hawaii

Objectives

To quantify the use of dietary supplements over a 24-hour and 1-month time frame, to determine the contribution of dietary supplements to the prevalence of dietary nutrient adequacy in the population, and to identify factors associated with supplement use, including characteristics of caregivers.

Design

Cross-sectional study.

Subjects/setting

Children aged 8 to 11 years from four primarily Native Hawaiian and Pacific Islander communities on Oahu (n=115) and the island of Hawaii (n=70).

Methods

A 24-hour food recall and a dietary supplement record were collected and analyzed for each child. Demographic and supplement use data were collected for each caregiver.

Statistical analyses

Significant differences between supplement users and nonusers were determined by χ² analysis. Prevalence of dietary nutrient adequacy with and without intake from dietary supplements was calculated using PC-Side software (version 1.02, 2001, Department of Statistics and Center for Agricultural and Rural Development, Iowa State University, Ames).

Results

Use of any dietary supplement by children in the previous day and month was 26% (n=48) and 40% (n=74), respectively. Prevalence of dietary nutrient adequacy from foods alone ranged from 33% to 100%, and increased to 59% to 100% when the nutrient contribution from dietary supplements was included. The largest increases in nutrient adequacy were for vitamins A, E, and C. Use of dietary supplements was most strongly associated with use of dietary supplements by caregivers, as well as with younger age of child, and greater years of caregiver education.

Conclusions

Dietary supplements are being used by a large percentage of these children in Hawaii and use is associated with use by their caregivers. The nutrient contribution from dietary supplements increased the prevalence of nutrient adequacy for several nutrients.     

Girls' Early Sweetened Carbonated Beverage Intake Predicts Different Patterns of Beverage and Nutrient Intake across Childhood and Adolescence

Background

Information is limited on persistence of early beverage patterns throughout childhood and adolescence and their influence on long-term dietary intake.

Objective

To describe changes in beverage intake during childhood and assess beverage and nutrient intake from ages 5 to 15 years among girls who were consuming or not consuming sweetened carbonated beverages (soda) at age 5 years.

Design/subjects

Participants were part of a longitudinal study of non-Hispanic white girls and their parents (n=170) assessed biennially from age 5 to 15 years starting fall 1996.

Statistical analyses

At each assessment, intakes of beverages (milk, fruit juice, fruit drinks, soda, and tea/coffee), energy, macronutrients, and micronutrients were assessed using three 24-hour recalls. Analyses of longitudinal changes and the interaction between beverage type and age were conducted using a mixed modeling approach. Girls were categorized as either soda consumers or nonconsumers at age 5 years. A mixed modeling approach was used to assess longitudinal differences and patterns of change in beverage and nutrient intake between soda consumption groups.

Results

Early differences in soda intake were predictive of later soda and milk intake and of differences in selected nutrients. Relative to girls who were not consuming soda beverages at age 5 years, soda consumers at age 5 years had higher subsequent soda intake, lower milk intake, higher intake of added sugars, lower protein, fiber, vitamin D, calcium, magnesium, phosphorous, and potassium from ages 5 to 15 years.

Conclusions

Soda consumption at age 5 years predicted patterns of nutrient intake that persisted during childhood and into adolescence. Diets of soda consumers were higher in added sugars and lower in protein, fiber, calcium, vitamin D, magnesium, phosphorous, and potassium. Findings provide a more complex picture regarding the emergence of early beverage patterns and their predictive effects on nutrient intake across childhood and adolescence.     

Cluster Analysis Defines Distinct Dietary Patterns for African-American Men and Women

Background

African Americans have a higher prevalence of diet-related chronic diseases than the general US population. Recent evidence suggests that examining dietary patterns rather than specific nutrients may better allow public health professionals to translate national dietary goals into practical dietary recommendations that are culturally relevant and sex-specific.

Objective

To examine and characterize the dietary patterns of African-American men and women using cluster analysis.

Design

Participants older than the age of 18 years were recruited from a variety of locations and completed a self-administered questionnaire.

Subjects/setting

Seven-hundred sixty-three African-American men and women in North Central Florida.

Statistical analyses performed

Cluster analysis was done with the VARCLUS procedure and Ward's clustering approach in the Statistical Analysis System program. The pseudo-t² statistic was then used to identify the optimal numbers of clusters of men and women with distinctive food-consumption patterns.

Results

Cluster analyses identified six clusters of men with 13 distinctive dietary patterns and six clusters of women with 15 distinctive dietary patterns. Pairwise comparisons of group means indicated notable differences in intakes between clusters of women in all but two food clusters. Pairwise comparisons of group means indicated notable differences in intakes between clusters of men in all but two food clusters.

Conclusions

The study illustrated that cluster analysis can be used to identify groups of African Americans with unique patterns of food consumption. They also suggest that a single “typical” eating pattern does not exist for African Americans and that dietary pattern vary by sex.     

The Association between Food Patterns and the Metabolic Syndrome Using Principal Components Analysis: The ATTICA Study

Background

Dietary habits have been associated with the prevalence of the metabolic syndrome.

Objective

The associations between foods or food patterns and the characteristics of the metabolic syndrome were evaluated.

Design

Cross-sectional survey.

Subjects

During 2001 to 2002, 1,514 men (aged 18 to 87 years) and 1,528 women (aged 18 to 89 years) without any clinical evidence of cardiovascular disease were randomly enrolled, from the Attica region in Greece.

Main outcome measures

Dietary habits were evaluated using a semiquantitative, food frequency questionnaire. Characteristics of the metabolic syndrome (ie, blood pressure, waist circumference, glucose, triglycerides, and high-density lipoprotein cholesterol) were also measured.

Statistical analysis

Principal components analysis was applied to extract dietary patterns from 22 foods or food groups. Multivariate regression analysis evaluated the associations between the extracted dietary patterns and characteristics of the metabolic syndrome.

Results

Six components were derived explaining 56% of the total variation in intake. Component 1 was characterized by the consumption of cereals, fish, legumes, vegetables, and fruits (explained variation 19.7%); component 2 was characterized by the intake of potatoes and meat (explained variation 11.7%), component 6 was characterized by alcohol intake (explained variation 4.8%), whereas the other components were mainly characterized by consumption of dairy and sweets. After adjusting for various confounders, component 1 was inversely associated with waist circumference, systolic blood pressure, triglycerides, positively associated with high-density lipoprotein cholesterol levels, and inversely with the likelihood of the metabolic syndrome (odds ratio [OR] 0.87, 95% confidence interval [CI] 0.79 to 0.97), whereas components 2 and 6 were positively correlated with the previous indexes, and the likelihood of having the metabolic syndrome (OR 1.13, 95% CI 1.05 to 1.21 and OR 1.26, 95% CI 1.21 to 1.33).

Conclusions

A dietary pattern that includes cereals, fish, legumes, vegetables, and fruits was independently associated with reduced levels of clinical and biological markers linked to the metabolic syndrome, whereas meat and alcohol intake showed the opposite results.     

Fruit and vegetable intake among rural youth following a school-based randomized controlled trial

Objective

We implemented a theory-based randomized controlled trial (Living Free of Tobacco, Plus (LIFT +) in ten rural middle schools and assessed impact on tobacco use and fruit/vegetable (F/V) intake in 2008-2010. Data on F/V intake at baseline, immediate post intervention, and 1-year follow-up are presented.

Methods

Schools were randomized to intervention or control groups. Goal setting, peer leaders, and class workshops with parent involvement, were intervention features; community partners were supportive. Seventh graders filled out surveys on health behaviors, psycho-social variables, and demographic characteristics. Adjusted models comparing intervention and control conditions were analyzed.

Results

Sample (n = 1119) was 48.5% female, 50% White, with a mean age of 12.7 years. Mean F/V servings were significantly higher in intervention schools at immediate post (3.19 servings) and at 1-year (3.02 servings) compared to controls (2.90, 2.69 respectively). Knowledge of 5-a-day recommendation was significantly higher in intervention schools at immediate post test (75.0%) versus controls (53.8%) but not at 1-year follow-up.

Conclusions

Intervention schools reported significantly higher mean F/V servings at post intervention and 1-year, and for knowledge of F/V recommendations at immediate post compared to controls. Higher levels of parent and community involvement may further increase F/V intake in future interventions.ClinicalTrials.gov Identifier: NCT01412697.     

A cohort study of developmental polychlorinated biphenyl (PCB) exposure in relation to post-vaccination antibody response at 6-months of age

Background

Extensive experimental data in animals indicate that exposure to polychlorinated biphenyls (PCBs) during pregnancy leads to changes in offspring immune function during the postnatal period. Whether developmental PCB exposure influences immunologic development in humans has received little study.

Methods

The study population was 384 mother-infant pairs recruited from two districts of eastern Slovakia for whom prospectively collected maternal, cord, and 6-month infant blood specimens were available. Several PCB congeners were measured in maternal, cord, and 6-month infant sera by high-resolution gas chromatography with electron capture detection. Concentrations of IgG-specific anti-haemophilus influenzae type b, tetanus toxoid, and diphtheria toxoid were assayed in 6-month infant sera using ELISA methods. Multiple linear regression was used to estimate the relation between maternal, cord, and 6-month infant PCB concentrations and the antibody concentrations evaluated at 6-months of age.

Results

Overall, there was little evidence of an association between infant antibody concentrations and PCB measures during the pre- and early postnatal period. In addition, our results did not show specificity in terms of associations limited to a particular developmental period (e.g. pre- vs. postnatal), a particular antibody, or a particular PCB congener.

Conclusions

At the PCB concentrations measured in this cohort, which are high relative to most human populations today, we did not detect an association between maternal or early postnatal PCB exposure and specific antibody responses at 6-months of age.     

Methodology for adding glycemic index values to 24-hour recalls

Objective

To describe a standardized method to assign glycemic index (GI) values to food items, obtained from 3 × 24-h recalls among Aboriginal and Torres Strait Islander and non-Indigenous Australian children, which can be adapted for use with simple food composition databases.

Methods

Four published GI databases were used as the source of GI values. Changes were made to a previously published methodology for GI value assignment to accommodate the needs of the Many Rivers Diabetes Prevention Project.

Results

There were 1132 food items in the recall database. Two hundred nineteen (19.3%) food items were directly linked to the FoodWorks GI database and 545 (48.1%) items were assigned the GI value of a “closely related” food item in the four GI databases used. Among the top carbohydrate contributors, 113 (35.3%) items have a direct linkage with the FoodWorks GI database. The mean ± SEM dietary GI and glycemic load (GL) of the study population resulting from this methodology are 57.5 ± 0.3 and 143.4 ± 2.6, respectively.

Conclusion

This simple method provides opportunities for countries without food composition database that are comprehensive for GI/GL but which contain accurate information on carbohydrates in foods to assign high-quality GI values to food items in epidemiological studies based on 24-h recalls.     

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.     

Weight Control Behaviors and Dietary Intake among Adolescents and Young Adults: Longitudinal Findings from Project EAT

Background

Cross-sectional research has found that dieting during adolesence and the use of extreme weight control behaviors are related to less healthful dietary patterns; however, little is known regarding longitudinal relationships.

Objective

To describe patterns of weight control behavior over 5 years and examine relationships with nutritional outcomes in adolescents and young adults.

Design

Population-based, longitudinal study in Minnesota. Youth completed Time 1 surveys in 1998-1999, and Time 2 surveys were completed in 2003-2004.

Subjects/setting

The Project EAT (Eating Among Teens) survey and the Youth and Adolescent Food Frequency Questionnaire were completed by 1,242 females and 1,007 males in school classrooms at Time 1 and by mail at Time 2.

Outcome measures and statistical analyses performed

Generalized linear modeling was used to predict each Time 2 outcome of interest (ie, meal and snack frequencies and dietary intake) across patterns of healthful and unhealthful weight control behavior (ie, never-engaging, stopping, starting, and persisting).

Results

Approximately 45% of females and 17% of males reported persistent use of unhealthful weight control behaviors at both time points. Persisting to use only healthful weight control behaviors was reported by 10% of females and 15% of males. Among females, persistent use of unhealthful weight control behavior was associated (P<0.05) with measures of poorer dietary intake (eg, lower intakes of calcium and vegetables) and less frequent meals, whereas persistent use of healthful weight control behavior was associated with measures (P<0.05) of better dietary intake (eg, less fast food and fewer sugar-sweetened drinks). Among males, few associations were observed between dietary intake and either unhealthful or healthful weight control behavior.

Conclusions

Health professionals should guide youth who have weight concerns by encouraging healthful eating habits to achieve or maintain appropriate weight and nutrition goals.     

Associations between Lifestyle Patterns and Body Mass Index in a Sample of Greek Children and Adolescents

Background

Although eating and physical activity behaviors have been previously individually investigated with regard to overweight in children, multidimensional lifestyle patterns, based on these behaviors, have not been explored.

Objective

To assess lifestyle patterns in relation to body mass index (BMI), in a nationally representative sample of the Greek pediatric population

Design

Cross-sectional study. Data were collected from May through July 2007.

Subjects

The sample consisted of 1,305 children and adolescents (ages 3 to 18 years).

Main outcome measures

Information on participants' dietary intake, eating behaviors, physical activity habits, and BMI were collected. Adherence to the Mediterranean diet guidelines was evaluated using the KIDMED Mediterranean diet quality index; the higher the score in this index the more favorable the dietary pattern. The Goldberg cut-off limits for the ratio of energy intake/basal metabolic rate were used to evaluate dietary low energy reporting and participants were accordingly classified as low-energy reporters.

Statistical analysis

Principal component analysis was performed to identify participants' lifestyle patterns. Associations between BMI and lifestyle patterns were further evaluated using multiple linear regression analyses, after controlling for potential confounders.

Results

Principal component analysis identified seven lifestyle patterns explaining 85% of the total variance of lifestyle habits. A lifestyle pattern characterized by higher eating frequency, breakfast consumption and higher KIDMED score was negatively associated with BMI (standardized β=−.125, P<0.001), after controlling for age, sex, and parental education. The association remained significant even when low-energy reporters were excluded from the analysis.

Conclusions

Results from the study suggest a potential intercorrelation and protective action of selected eating behaviors, namely eating frequency, breakfast consumption, and adherence to the Mediterranean diet, against overweight and obesity in children and adolescents.     

Dietary pattern change and acculturation of Chinese Americans in Pennsylvania

Objective

To obtain information about dietary pattern change of Chinese Americans in Pennsylvania and its relationship with demographic characteristics and acculturation indicators.

Design

A cross-sectional self-administered survey.

Subjects

A convenience sample of 399 Chinese Americans.

Statistical analyses performed

t Tests, analysis of variance with Tukey post-hoc tests, Spearman rank correlation, and χ² test.

Results

After immigration, Chinese Americans increased consumption frequency of all seven food groups (grains, vegetables, fruits, meat/meat alternatives, dairy products, fats/sweets, and beverages) and Western foods while consumption frequency of traditional Chinese foods decreased. Dietary variety also increased after immigration. Higher education and higher income levels were associated with a larger increase in consumption frequency of grains, vegetables, and fruits. Persons who resided in the United States for a longer period of time shared a greater increase in their consumption frequencies of vegetables, fats/sweets, and beverages. Persons with better English proficiency had a greater increase in their consumption frequency of grains, fruits, meat/meat alternatives, and fats/sweets.

Conclusions

This study can help nutrition educators design appropriate educational programs for first-generation Chinese Americans that can facilitate the adoption of more healthful dietary practices. Nutrition educators should consider the dietary changes of Chinese-American participants, such as skipping breakfast and increased consumption frequency of fats, sweets, and soft drinks, which were observed in this study. For example, acculturated first-generation Chinese Americans should be encouraged to decrease fats, sweets, and soft-drink consumption. Less-acculturated persons should be encouraged to maintain their healthful dietary pattern and increase consumption of vegetables and fruits.     

Participation rates in the selection of population controls in a case-control study of colorectal cancer using two recruitment methods

Objectives

Low participation rates in the selection of population controls are an increasing concern for the validity of case-control studies worldwide.

Methods

We conducted a pilot study to assess two approaches to recruiting population controls in a study of colorectal cancer, including a face-to-face interview and blood sample collection. In the first approach, persons identified through a population roster were invited to participate through a telephone call by an interviewer telephoning on behalf of our research center. In the second approach, individuals were identified from the lists of selected family practitioners and were telephoned on behalf of the family practitioner.

Results

When the second method was used, participation rates increased from 42% to 57% and the percentage of refusals decreased from 47% to 13%. The reasons for refusing to participate did not differ significantly between the two methods.

Conclusions

Contact through the family practitioner yielded higher response rates in population controls in the study area.     

Predictors of Dietary Change and Maintenance in the Women’s Health Initiative Dietary Modification Trial

Objective

To identify predictors of dietary change to and maintenance of a low-fat eating pattern (<20% energy from fat, ≥5 servings fruits/vegetables daily, and ≥6 servings grains daily) among a cohort of postmenopausal women. Candidate predictors included intrapersonal, interpersonal, intervention program characteristics, and clinical center.

Design

Longitudinal study within the Women’s Health Initiative Dietary Modification Trial. Dietary change was evaluated after 1 year of participation in the Women’s Health Initiative Dietary Modification Trial, and dietary maintenance after 3 years.

Subjects

Postmenopausal women aged 50 to 79 years at baseline who were randomized to the intervention arm of the Women’s Health Initiative Dietary Modification Trial (n=19,541).

Statistical analysis

Univariate and multivariate linear regression analysis was performed and associations evaluated between candidate predictors and each of the three dietary goals: percent energy from fat, fruit/vegetable servings, and grain servings.

Results

Year 1 (change) predictors of percent energy from fat (P<0.005) included being younger (β=2.12; 70 to 79 years vs 50 to 59 years), more educated (β=-.69; college vs high school), more optimistic (β=-.07), attending more sessions (β=-.69), and submitting more self-monitoring records (β=-.74). At year 3 (maintenance), the predictors of percent energy from fat (P<0.005) included attending more sessions (β=-.65) and submitting more self-monitoring scores (β=-.71). The analytic model predicted 22% of the variance in fat intake at year 1 and 27% at year 3 (P<0.01).

Conclusions

The strongest predictors of dietary change and maintenance were attending intervention sessions and self-monitoring dietary intake. Novel was the finding that optimism predicted dietary change.     

Development and Validation of a Comprehensive Semi-Quantitative Food Frequency Questionnaire that Includes FODMAP Intake and Glycemic Index

Background

Fermentable, short chain carbohydrates (FODMAPs) have been identified as triggers for functional gastrointestinal symptoms. In addition, excess FODMAP consumption has been implicated in the onset of Crohn's disease, and animal studies suggest that a low glycemic index diet can impair absorption of fructose, a major dietary FODMAP. Such hypotheses cannot be tested without the ability to quantify FODMAP ingestion with a validated dietary assessment tool.

Objective

To assess the validity and reproducibility of a 297-item comprehensive, semi-quantitative food frequency questionnaire (FFQ) in estimating intake of macro- and micronutrients, FODMAPs, and glycemic index/load.

Subjects/setting

One hundred healthy participants were recruited to complete the FFQ on two occasions, plus four 1-week food diaries kept during a 12-month period. Participants exhibiting major dietary change during the study period or low energy reporting on the FFQ were excluded.

Main outcome measures

Validation and reproducibility of the semi-quantitative FFQ by comparison with the mean of four 1-week food diaries.

Statistical analyses performed

Validation was assessed using Wilcoxon signed rank test, Spearman's correlation, Bland-Altman, and weighted κ statistics. Reproducibility was examined using Shrout-Fleiss intraclass correlation coefficient.

Results

Seventy-two participants fulfilled inclusion and exclusion criteria. Demographics of the participants were comparable with 2006 Australian Census data. Consistent with other reported FFQs, the FFQ overestimated nutrient intake by a mean 140% (range=95% to 249%). However, based on the other analyses performed, it demonstrated validity for intake of sugars, fiber, alcohol, glycemic index, glucose, FODMAPs, calcium, folate, phosphate, potassium, iron, and magnesium; moderate validation for energy, total fat, saturated fat, carbohydrates, sodium, thiamin, sucrose, and retinol; poor validation for protein, mono/polyunsaturated fat, starch, glycemic load, niacin, and zinc. Riboflavin intake was not validated. Intraclass correlation coefficients for reproducibility ranged from 0.352 to 0.928.

Conclusions

The FFQ was validated for assessment of a wide range of nutrients, including the new class of carbohydrates, FODMAPs, and glycemic index. This provides a useful tool for dietary research, particularly in the area of gastroenterological disorders.     

Dietary pattern classifications with nutrient intake and health-risk factors in Korean men

Objective

This study was performed to identify dietary patterns in Korean men and to determine the associations among dietary patterns, nutrient intake, and health-risk factors.

Methods

Using baseline data from the Korean Health and Genome Study, dietary patterns were identified using factor analysis of data from a validated food-frequency questionnaire, and associations between these dietary patterns and health-risk factors were analyzed.

Results

Three dietary patterns were identified: 1) the “animal-food” pattern (greater intake of meats, fish, and dairy products), 2) the “rice-vegetable” pattern (greater intake of rice, tofu, kimchi, soybean paste, vegetables, and seaweed), and 3) the “noodle-bread” pattern (greater intake of instant noodles, Chinese noodles, and bread). The animal-food pattern (preferred by younger people with higher income and education levels) had a positive correlation with obesity and hypercholesterolemia, whereas the rice-vegetable pattern (preferred by older people with lower income and educational levels) was positively associated with hypertension. The noodle-bread pattern (also preferred by younger people with higher income and education levels) had a positive association with abdominal obesity and hypercholesterolemia.

Conclusion

This study identifies three unique dietary patterns in Korean men, which are independently associated with certain health-risk factors. The rice-vegetable dietary pattern, modified for a low sodium intake, might be a healthy dietary pattern for Korean men.