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Recently, nutrition scientists have tended prefer to assess diet-disease relations through dietary pattern approach rather than previous traditional approaches (nutrient- or food-oriented approach). Identifying dietary patterns allows us to consider the whole diet, not ingredients a relationship helps to find associations beyond those described based on foods or nutrients. This approach is also beneficial when traditional analyses in nutritional epidemiology show weak associations. Dietary pattern approach is more realistic than the food- or nutrient-based approach. Inter-correlations and biological interactions between foods and nutrients confound the associations of single foods or nutrients with a certain chronic disease. Several studies have provided evidence supporting the use of dietary pattern approach in nutritional epidemiology. Most of these studies have indicated that dietary patterns identified by factor or cluster analysis are significantly associated with chronic diseases. Data on major dietary patterns in developing countries, including Iran, are scarce. This review aims to provide more detailed information about methods of measurement, as well as the advantages and disadvantages of dietary pattern approach to help and encourage nutrition scientists in the country to use this approach in future investigations.

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Background and Objective: Dietary determinants of weight gain remain controversial. The assessment of dietary patterns has been increasingly used as an alternative to nutrient- or food-based analysis. The aim of this study was to determine the association between changes in food patterns and changes in body weight and body mass index in a group of Tehrani adults . Materials and Methods: As part of the Tehran Lipid and Glucose Study, a total number of 82 men and 124 women (≥18 years old) were followed up between 1999-2001 and 2004-2007 the mean follow-up period was 6 years. They were divided into two groups: normal weight (BMI<25) and overweight/obese (BMI25). Dietary intake was assessed using a food frequency questionnaire and two 24-hour dietary recalls. The food items were divided into 21 groups according to their nutrients contents. Food patterns were derived by factor analysis at each time interval. Changes in food patterns, weight and BMI were calculated by subtracting the factor scores of each food pattern, weight and BMI in the first period from their respective values in the second period. Results: The mean ages of the men and women at the beginning of the study were 45±11 and 39±14 years, respectively. Three food patterns were identified in the two periods of the study, with a total variance of 29 and 33%, respectively: “healthy”, “western”, and “mixed”. In both periods, refined grains, salty snacks, sauces, fast foods, processed meat products and sweetened beverages were the major contributors to the western dietary pattern, while the healthy pattern included vegetables, fruits, poultry and fish, dairy products and whole grains. There were no significant differences in the mean delta factor scores of the healthy and the western dietary patterns between men and women. In a multivariate adjusted model, after adjusting for confounding factors (β=0.32, R2=0.25, P<0.001), the strongest predictor of a change in body weight was a change to the western food pattern as compared to healthy dietary pattern. In addition, based on multiple regression analysis, changing to the western pattern caused a higher increase in BMI in overweight/obese individuals than in those with a normal weight (β=0.41, R2=0.22, p<0.001). Conclusion: Adherence to the western food pattern was associated with changes in body weight and BMI. This effect was greater in overweight/obese individuals.

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Background and Objective: Few studies have investigated the association between dietary patterns and socioeconomic and demographic factors. The aim of this study was to detect major dietary patterns and assess their relationship with socioeconomic and demographic factors among 20-50 year-old women living in the north of Tehran. Materials and methods: In this cross-sectional study 460 women, aged 20-50 year-old, living in the north of Tehran were selected by stratified random sampling. Dietary data (for the previous year) was collected by a semi-quantitative food frequency questionnaire, and information on the socioeconomic and demographic factors was obtained by interview. Factor analysis was used for identifying major dietary patterns. The association between major dietary patterns and socioeconomic and demographic factors was assessed by covariance analysis. Results: Two major dietary patterns were detected: 1. Healthy Pattern (high in, fruits yellow vegetables, cruciferous vegetables, tomatoes and other vegetables yogurt drink and low-fat dairy products poultry olives nuts fruit juice potatoes garlic coffee dried fruits and legumes), and 2. Unhealthy Pattern (high in processed meat mayonnaise soft drinks sweets refined grains snacks industrial juice red meat nuts French fries hydrogenated fats egg, butter and high-fat dairy products sugars and organ meats). After adjustmnent for confounders, the Azari ethnic group in comparison with the Fars ethnic group (B= 0.44 p<0.01), and living in District 7 in comparison with living in District 3 (B= 0.39 p<0.05) were positively , and age (B= - 0.04 p<0.01), university education (B= -0.34 p<0.05) and total monthly family income (B= - 0.25 p<0.05) negatively, associated with the unhealthy diatery pattern.On the other hand, age (B= 0.03 p<0.01) and housing surface area (square meters_ per head) (B= 0.21 p<0.01) had a positive, and duration of residence in Tehran, a negative, association with the healthy pattern (B= - 0.01 p<0.01). Conclusion: Socioeconomic and demographic factors influence dietary patterns of the women. It is suggested that these factors be considered in the future assessments of associations between dietary patterns and disease.

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Background and objectives: The application of factor analysis methodology to dietary patterns has recently become of considerable interest in nutritional epidemiology. Rather than considering nutrients or foods individually, pattern analysis provides an alternative approach to study highly correlated food groups commonly consumed. In this study we tried to identify major dietary patterns in our study population in the Kurdistan Province, Iran, and determine their associations with the risk of esophageal squamous-cell carcinoma in a hospital-based case-control study. Materials and methods: In this case-control study, 47 patients with esophageal squamous-cell carcinoma and 96 controls were interviewed to obtain information on general characteristics, physical activity, and food consumption frequency (125 food items). Following classification of food items in groups, factor analysis was used to identify possible dietary patterns, and then the odds ratio for esophageal squamous-cell carcinoma was estimated. The software used was SSPS-14. Results: Two major dietary patterns were identified: Pattern1: the healthy dietary pattern (including nuts, fruits, green leafy vegetables, yellow vegetables, other vegetables, tomatoes, olives, low-fat dairy products, fish, Doogh (a traditional buttermilk), and cabbages), and Pattern 2: the western dietary pattern (including hydrogenated fats, sugar, sweets and desserts, salt, pickles, eggs, soft drinks, tea, and small amounts of liquid oil). After adjustment for confounding factors such as age, sex, years of education, body mass index, physical activity, symptomatic gastroesophageal reflux, and smoking, a high score of Pattern 1 was associated with a reduced risk esophageal squamous-cell carcinoma by 67% (high second median vs. low 1st median, OR=0.33, 95%CI=0.12-0.86), whereas the Pattern 2 diet significantly increased the risk of the disease (high second median vs. low 1st median, OR=9.8, 95%,CI=3.2-29.7 p<0.001). Conclusion: Our results suggest that a healthy diet tends to reduce the risk of esophageal squamous-cell carcinoma, whereas a western-type diet increases the risk of this kind of cancer.

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Background and objectives: The metabolic syndrome (MetS) is associated with overweight and obesity. It is also considered a risk factor for cardiovascular disease and type II diabetes. Almost one-third of Iranian adults are afflicted with MetS, with a higher prevalence among women. In this study the relationship of dietary pattern with the metabolic syndrome among non-menopausal women (18-50 yr) in District 13 of Tehran was determined. Materials and Methods: This was a nested case-control study using the Tehran Lipid Glucose Study (TLGS) data on 920 non-menopausal women (18-50 yrs) as the case group. The control group was an equal number of subjects matched for age. Dietary intakes were assessed with a 168-iteme semi-quantitative food frequency questionnaire (26 food groups). Using factor analysis, the predominant food patterns were identified. The odds ratio of MetS (defined according to the International Diabetes Federation guidelines) and its components was calculated using logistic regression, after adjusting for confounding variables. Results: Two predominant dietary patterns were identified. The desirable food pattern was characterized by the consumption of raw vegetables, fruits, starchy vegetables, olives, fried vegetables, low-fat d high-fat dairy products, legumes, nuts, eggs, oil, whole grains, fish, and chicken. In the undesirable food pattern the widely consumed food items included soft drinks, commercial fruit juices, cookies and high-sugar sweets, ready-to-eat foods, mayonnaise, snacks (potato chips and puffed corn), oil, pickles, organ meats, refined grains, meat, and salt. After adjustment for various confounding variables (energy intakes, energy expenditure, education level, job, family history of diabetes or stroke, smoking, and BMI), the desirable food pattern was found to be inversely associated with MetS (odds ratio=0.87 95% confidence interval: 0.16-0.73, P-value <0.001) and hyperglycemia (odds ratio=0.34 95% confidence interval: 0.13-0.87, P-value <0.05). No associations were observed between MetS and the undesirable food pattern, and of the components of MetS only triglyceride level was associated with this food pattern (odds ratio=2.17 95% confidence interval: 1.09- 4.32, P-value <0.001). Conclusion: The desirable food pattern is significantly inversely associated with the metabolic syndrome, whereas the undesirable food pattern has no association. Keywords: Metabolic syndrome, Food pattern, Non-menopause women, Factor analysis

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Background and Objective:This study was conducted to determine the relationship between stunting and major dietary patterns among the first-grade pupils in Tehran in 2008. Materials and Methods:In this case-control study, children’s height (n=3147) was measured in 5 areas of Tehran by expeienced nutritionists using standard protocols. Children with a height lower than the 5th percentile of height for age of the CDC2000 standard were considered as stunted (n = 86, the case group). Control children were selected randomly from among healthy, non-stunted children with the same age and sex (n=308). Data on demographic characteristics, socio-economic status, birth weight and length, and duration of breast feeding were collected using standard questionnaires. In addition, two 24-hour dietary recall questionnaires were completed for each subject on 2 cosecutive days by interviewing their mothers. Factor analysis was used to identify major dietary patterns. Logistic regression models were adjusted for sex, mother's age and education, father's education, birth weight, family size, and energy intake. Results: There were significant differences between the stunted children and their control group with regard to sex, birth weight, age of mother, and parents' education of (P<0.05). Based on the 24-hour dietary recalls, the mean consumptions of dairy products (308±167 g/day) and dried fruits and nuts (2.58±9 g/day) in the case group were significantly lower than the respective control values (7.15±26 and 382±232 g/day, respectively p<0.05). However, consumption of the fat and oils group in the case group (37.85±29 g/day) was higher than in the control group (30.94±22 g/day P< 0.05). Three dietary patterns were identified using factor analysis: dietary pattern 1, high in bread, potatoes, fats, eggs, relish, other vegetables, sugar, and soft drinks dietary pattern 2, high in leafy vegetables, fast foods, nuts, other cereals, fruits, legumes, and offal and dietary pattern 3, high in biscuits and cakes, chicken, dairy products, fruits, etc. Dietary patterns 1 and 2 were not significantly associated with stunting, while children in the third quartile of dietary pattern 3 had a lower risk for stunting as compared to those in the first quartile of that dietary pattern (p<0.05). Conclusion: It seems that following dietary patterns high in protein (e.g., dairy and meat products) and carbohydrate (e.g., fruits and biscuits/cakes) may reduce the risk of stunting in children. Keywords: Children, Stunting, Factor analysis, Dietary pattern

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Background and Objective: Few studies have examined the association between dietary patterns and bone mineral density (BMD). The aim of the present study was to determine the association between dietary patterns and BMD in a sample of postmenopausal women living in Tehran. Materials and Methods: A group of 160 postmenauposal women participated in this cross-sectional study. Data were collected on their general characteristics, physical activity, and food consumption frequency using questionnaires, and their lumbar spine and femoral neck BMD were measured by dual-energy X-ray absorptiometry. Dietary patterns were identified using factor analysis, and multivariate logistic regression was used to estimate odds ratio (OR) for having lower BMD (values less than the median) as related to dietary patterns. Results: Six dietary patterns were identified. The first (high consumption of high-fat dairy products, organ meats, red and processed meats, and whole grains) and the second (high consumption of French fries, mayonnaise, sweets and desserts, and liquid oils) patterns were associated with a lower BMD. Analysis of the data, after adjustment for potential confounders, showed that women in the second median of the first or the second dietary pattern scores were more likely to have a lower BMD at lumbar spine (OR=2.29, 95% CI: 1.05-4.96, P=0.04) and femoral neck (OR=2.83, 95% CI: 1.31-6.09, P<0.01), respectively. Conclusion: Dietary patterns rich in foods with a high content of saturated fats (similar to the first pattern) or those with a low density of essential nutrients for bone health (similar to the second pattern) may be negatively associated with BMD in postmenopausal women living in Tehran. Keywords: Dietary patterns, Bone mass density, Postmenopausal women, Factor analysis

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Background and Objective: Few studies have examined the association between dietary patterns and overweight or obesity among adolescents. The aim of present study was to determine the association between major dietary patterns and overweight or obesity in a sample of Iranian adolescent girls. Materials and Methods: A group of 400 high school girl students aged 14-17 living in Ahar, Iran, participated in this cross-sectional study. Semi-quantitative food frequency and general questionnaires were completed for all participants and their anthropometric characteristics were determined. Factor analysis was used to identify major dietary patterns. Odds ratios (ORs) for having overweight or obesity in relation to identified dietary patterns were estimated using multivariate logistic regression analysis. Results: Three major dietary patterns were identified. After adjusting for potential confounders, participants who had higher scores for the unhealthy (high consumption of mayonnaise, refined cereals, French fries, nonrefined cereals, high-fat dairy, organ meats, and red or processed meats) and the healthy (high consumption of vegetables, legumes, potatoes, fruit and fruit juices, liquid oils, olive, fish, low-fat dairy, and poultry) dietary patterns were more (OR=3.02, 95% CI: 1.81-5.03, P˂0.001) and less (OR=0.17, 95% CI: 0.09-0.29, P˂0.001) likely to have overweight or obesity, respectively, compared to participants with lower scores. Conclusion: The results of this study suggest that clear and specific dietary patterns can be identified among Iranian adolescent girls, which are related to risk of overweight or obesity. Keywords: Major dietary patterns, Overweight, Obesity, Adolescent girls, Factor analysis

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Background and Objective: An appropriate dietary pattern plays important role in the control and treatment of rheumatoid arthritis (RA). Accordingly, this study aimed to investigate the association between dietary patterns and indicators of disease activity in patients with RA. Materials and Methods: This cross-sectional research studied 102 patients with RA attending to the professional Rheumatology Clinic of Ahvaz Aria Hospital in 2012. Data were collected by using demographic, anthropometric and semi-quantitative food frequency (FFQ) questionnaires. The patients’ Pain intensity was evaluated by VAS index and CRP and RF levels were measured in fasting blood samples. Then data analysis was performed by SPSS software (version 17) using independent t-test, analysis of covariance, and multivariate linear regression analysis. Results: In this study, three major dietary patterns were identified: healthy dietary pattern, Western pattern, and High-protein pattern. After adjusting of the confounding variables, healthy dietary pattern was associated with lower body mass index(BMI), waist circumference, pain intensity, and C-reactive protein levels (P<0.05). On the other hand, Western dietary pattern showed a positive correlation with BMI, waist circumference, body fat percentage, and pain intensity (P<0.05). In High-protein dietary pattern, the patients, who were in the highest tertile, significantly reported lower pain intensity (P=0.007). Conclusion: Adherence to a healthy dietary pattern, which includes high amount of fruits, vegetables, beans, garlic, olive and nuts, can lead to improvement of disease condition in RA patients. Keywords: Dietary pattern, Rheumatoid arthritis, Inflammation, Factor analysis

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Background and Objectives: Today nutritionists use dietary pattern to find out the effect of food in health. Most common statistical methods to determine dietary pattern are factor analysis and cluster analysis.Mixture models are a combination of k probability distribution with different probability and provide a parametric model for unknown distributional shapes. Recently mixture model as the third method is used to determine dietary pattern. Then we compared this new method with other two methods available for this purpose. Materials & Methods: We analyzed data from 25 food groups of 400 high school girls in Ahar (Rashidi’s data), and compared the results of factor analysis, cluster analysis and multivariate normal mixture model for dietary pattern. Selection of the best mixture model was done by AIC and BIC criteria. Results: Three, two and five dietary pattern were obtained from factor analysis, cluster analysis and normal mixture model, respectively. Prevalence of these dietary patterns in normal mixture model was 6%,12%,34%,28%, and 20%, respectively. Conclusion: It is concluded that mixture model has two advantages over the two other methods. First, the proportion of each pattern in population is known and secondly, the average of consumption of each food group gets clear so more information can be obtained compared to the usual methods. Keywords: Mixture model, Factor analysis, Cluster analysis, Dietary pattern

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Background and Objectives: Depression is one of the main causes of disability, affecting 121 million individuals worldwide. Anti-depression drugs are successful for 60-80% of depression cases; however, less than 25% of these patients are treated with appropriate drugs. Considering the importance of nutrition-related factors, we aimed to identify dietary patterns as potential preventive or treatment agents to control the depression. This study will identify relationship between dietary patterns and depression.

 Materials and Methods: In total, 110 depressed patients, diagnosed by psychiatrists, and 220 healthy individuals were studied as the case and control groups, respectively. A semi-quantitative food frequency questionnaire was used to assess the dietary intakes, and the dietary patterns were extracted by factor analysis.

Results: Two dietary patterns were identified: Healthy and Unhealthy. There were significant relations between the dietary patterns and depression, as Healthy dietary pattern could decrease the risk (p=0.028) and Unhealthy dietary pattern could increase the risk of depression (p=0.03). The relationships were dose-dependent, as the risk of depression decreased with increasing the quartiles of Healthy dietary pattern, and increased with increasing the quartiles of Unhealthy dietary pattern (p≤0.02).

Conclusion: Consumption of healthy foods and avoiding unhealthy foods could be associated with the prevention and control of depression. Nevertheless, since food consumption is embedded in culture, the recommended diet should be based on the cultural differences, which demands further studies.

Keywords: Depression, Nutrition, Dietary pattern, Factor analysis, Case control study

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Background and Objectives: Based on the bio-psycho-social approaches, various studies have recently been carried out on dietary patterns and other health-linked behaviors in patients with psychiatric disorders. The purpose of this study was to investigate dominant dietary patterns in patients with bipolar spectrum disorders due to the great importance of dietary patterns in general health of people.
 Materials & Methods: In this cross-sectional and case-control study, 90 patients, who referred to Nekoei-Hedayati Hospital and diagnosed with bipolar spectrum disorders by psychiatrists, were participated as well as 90 healthy individuals as controls using convenience sampling. The two groups were studied using demographic and food frequency questionnaires. Data were analyzed using factor analysis and independent t-test.
Results: Factor analysis identified three dominant dietary patterns of 1) western dietary patterns, 2) healthy dietary patterns and 3) traditional dietary patterns. Results showed that people with bipolar disorders followed western and traditional dietary patterns, compared to the healthy group (p = 0/000).
Conclusion: Based on the findings, traditional and western dietary were dominant dietary patterns in patients with bipolar disorders. These eating habits might play important roles in health problems of these patients. Further longitudinal studies on the nutrition-health interactions within bipolar patients are suggested.