Meal-specific dietary patterns and biomarkers of insulin resistance in a sample of Iranian adults: a cross-sectional study.

Current research emphasizes the habitual dietary pattern without differentiating eating occasions. We aimed to assess meal-specific dietary patterns and insulin resistance indicators. This cross-sectional study was conducted on 825 Iranian adults. Dietary data were recorded by three 24-h dietary recalls. Dietary patterns were identified using principal component analysis (PCA) on main meals and an afternoon snack. Anthropometric measurements, blood pressure, and laboratory investigation, fasting plasma glucose (FPG), triglyceride, insulin, c-reactive protein (CRP) were done. Homeostatic model assessment for insulin resistance and sensitivity (HOMA-IR and HOMA-IS), Triglycerides and glucose (TyG-index), and Lipid accommodation product index were calculated. We used multivariate analysis of variance (MANOVA) analysis. Two major dietary patterns at the main meals and the afternoon were identified. Higher adherence to "Bread, vegetable, and cheese" dietary pattern at breakfast was related to lower FPG, and "Oil, egg, and cereals" showed a direct association with body mass index, FPG, and TyG-index at breakfast. The "Western" pattern in lunch and dinner directly related to waist circumference (WC) and body mass index, however, it was inversely related to HOMA-IS. This pattern at dinner was related to higher CRP. Higher adherence to "bread, cereals, and oil" pattern at afternoon snack was associated with a lower WC. These results indicated that unhealthy meal-specific dietary patterns are associated with a greater chance of obesity and insulin resistance risk. However, "Bread, vegetable, and cheese" dietary pattern at breakfast was related to lower FPG, and "bread, cereals, and oil" pattern in the afternoon was associated with lower WC.

Time-related meal patterns and breakfast quality in a sample of Iranian adults.

BACKGROUND: Some evidence shows that meal timing is associated with diet quality. We aimed to investigate the relationship between meal timing and breakfast quality in a sample of Iranian adults. METHODS: This cross-sectional study was conducted on 850 men and women living in Tehran, Iran. Dietary data was recorded by three non-consecutive 24-h dietary recalls. The Breakfast Quality Index (BQI) was calculated. Time-related meal patterns included the interval between the first and last meal (eating and fasting window), frequency of meals, length of sleep, and time of first and last eating occasion. The multiple linear regression analysis was used to identify the relationships between time-related meal patterns and BQI. RESULTS: The mean (95% CI) of BQI was 4.52 (4.45-4.65) and the maximum was 8. Bread, cheese, vegetables, fruits, energy, and carbohydrate intake showed positive associations with BQI scores. Longer fasting time showed a positive association with fruits (ß (CI 95%)) (0.11 (0.0003-0.005), and vegetable consumption (0.12 (0.009-0.07)) and BQI score (0.39 (0.001-0.06)). Time of first eating occasions indicated a negative association with protein and fat intake and BQI score. Time of last eating occasions showed a positive association with vegetables consumption and BQI score. The longer length of sleep was associated with a higher BQI score. The frequency of meals was significantly and positively related to energy and macronutrients intake and BQI. CONCLUSION: Earlier first and last meal, longer sleep length, longer fasting window, and a greater meal frequency were associated with a better breakfast quality.

Meal-specific dietary patterns and their contribution to habitual dietary patterns in the Iranian population.

Recent studies have focused on habitual intake without addressing meal-specific intakes. We aimed to identify meal-specific dietary patterns and their contribution to habitual dietary patterns. This cross-sectional study was conducted on 838 adults, both sexes who attended the health centres in Tehran. Dietary data were recorded by three 24-h dietary recalls (24hDR). Dietary patterns were identified by using principal component analysis on meal-specific and overall food intakes. Intraclass correlation (ICC) was used as a measurement of consistency across meals and days. Correlation analysis and linear regression (partial R2) were used for meals contribution. Four habitual dietary patterns were derived from average dietary intake of 3-d 24hDR labelled as 'Western', 'Healthy', 'Traditional' and 'Legume and broth'. Also, we identified two major dietary patterns on each meal level (factor 1 and 2 for breakfast, lunch, afternoon snack and dinner). The highest contribution of energy intake was observed in lunch (25·7 %), followed by dinner (20·81 %). Consistency of food groups was the highest across days (ICC tea = 0·58) and breakfasts (ICC tea = 0·60). Dinner had a strong correlation coefficient with the 'Western' habitual dietary pattern then followed by lunch. Similarly, dinner and lunch contributed the most (r and partial R2) to the 'Western' habitual dietary pattern. Our results suggest that habitual dietary patterns to several extents are formed at meal levels, and dinner has a greater contribution to the habitual dietary patterns in Iranian people. This may help planning for local dietary guidelines according to the time of eating to promote public health.

Habitual- and Meal-Specific Carbohydrate Quality Index and Their Relation to Metabolic Syndrome in a Sample of Iranian Adults.

Aim: Most studies on diet quality have focused on the habitual and overall intake of foods without considering intakes at specific eating occasions. This study aimed to assess the association between habitual- and meal-specific carbohydrate quality index (CQI) and metabolic syndrome (MetS) in Iranian adults. Methods: In this cross-sectional study, data from 850 participants were analyzed. Dietary information was obtained from a 3-day nonconsecutive 24 h recall. CQI was calculated from three criteria: dietary fiber, glycemic index, and solid carbohydrate/total carbohydrate ratio. The association between CQI and MetS was assessed by logistic regression. Results: The prevalences of MetS in the lowest and highest tertile of CQI were 30.1 and 33.7, respectively (P = 0.6). In habitual diet and all the three meals, we failed to find any significant association between tertiles of CQI and MetS either before or after adjustment for covariates. However, in the habitual meals [odds ratio (OR): 0.69, 95% CI: 0.47-0.96] and lunch meals (OR: 0.66; 95% CI: 0.47-0.94), the highest CQI in comparison to the lowest one, significantly decreased the low high-density lipoprotein (HDL). In addition, the trend of low-HDL with CQI in habitual meal and lunch meal was statistically significant. Conclusion: The results of this study showed that CQI was not associated with MetS and its components. Further investigations into the mechanisms underlying the role of carbohydrate quality in developing metabolic disorders are warranted.

The association between lunch composition and obesity in Iranian adults.

We aimed to assess the dietary composition of lunch meal using a posteriori-derived dietary patterns and to determine the association of lunch composition with obesity in a sample of Iranian adults. This cross-sectional study was conducted on 850 men and women in Tehran (aged 20-59 years). Dietary intakes were assessed using three 24-h dietary recalls, and dietary patterns were identified via principal component factor analysis. For each identified pattern, scores were calculated for each participant and then classified into tertiles. Central obesity was defined WHO criteria. General obesity was defined as a BMI of more than 30 kg/m2. Three major dietary patterns were identified at lunch meal using twelve food groups: 'Bread, grains and fat', 'Western' and 'Potato and eggs'. After adjustment for potential confounders, participants at the top tertile of the 'Bread, grains and fat' dietary pattern had greater odds for a higher waist-to-hip ratio (WHR), compared with those in the lowest tertile (OR: 1·44, 95 % CI 1·01, 2·07). However, we found no association between 'Western' or 'potato and eggs' patterns and WHR (OR: 0·89, 95 % CI 0·62, 1·28 and OR: 1·16, 95 % CI 0·69, 1·42, respectively). None of the identified dietary patterns was associated when defining obesity with waist circumference or BMI. In conclusion, participants had a greater chance of central obesity defined based on WHR following a lunchtime pattern with a higher and positive loading factor for 'Bread, grains and fat'.

The association between meal specific low carbohydrate diet score and cardiometabolic risk factors: A cross-sectional study of Iranian adults.

BACKGROUND AND AIM: Since evidence regarding low-CHO diet and cardiometabolic risk factors is controversial, this study aimed to assess the relation between low-CHO diet score and metabolic syndrome (MetS) and cardiometabolic risk factors among a group of Iranian adults. METHODS: This cross-sectional study was conducted with 840 subjects with the age range of 20-65 years. Dietary intakes were assessed by completing three 24-hour recalls. Total, animal- and vegetable-based low-CHO diet score were calculated. We used logistic regression with different models to determine whether there were relationships between low-CHO diet score and MetS and MetS components. RESULTS: We found that there was no significant association between low-CHO diet, animal-based and vegetable-based low-CHO diet scores and risk of MetS in three meals. Except for the animal-based low-CHO diet score, which was significantly associated with general obesity at lunch meal (OR: 1.17, 95% CI: 0.76-1.82, P = .03). There were a significant association between low-CHO diet and high-density lipoprotein cholesterol (HDL-C) levels in lunch meal (OR: 1.50, 95% CI: 1.06-2.14, P = .03). Vegetable-based low-CHO diet score was associated with a lower risk of elevated TG in lunch meal in the fully adjusted model (OR: 0.59, 95% CI: 0.39-0.90, P = .04). CONCLUSION: Diets with lower amounts of carbohydrate and higher contents of fat and protein were not significantly associated with the risk for MetS in Iranian adults. Only animal-based low-CHO diet score was significantly associated with general obesity at lunch meal.

Association of Nutrient Patterns and Their Relation with Obesity in Iranian Adults: a Population Based Study.

In the present research, we have evaluated the association between patterns of nutrient intake and obesity. The present cross-sectional study recruited 850 adults aged between 20-59 years old. Dietary intakes were assessed with three 24-hour recalls. As well, data on anthropometric measures were collected. General obesity was specified as body mass index ≥ 30 kg/m2. Factor analysis was conducted, and followed by a varimax rotation, was performed to extract major nutrient patterns. Our analysis identified three major nutrient patterns: The first nutrient pattern was characterized by the high consumption of saturated fatty acids (SFAs), protein, vitamins B1, B2, B6, B5, B3, B12, Zinc, and iron. The second nutrient pattern was rich in total fat, polyunsaturated fatty acids, monounsaturated fatty acids, SFAs, oleic acid, linolenic acid, zinc, vitamin E, α-tocopherol, and ß-carotene. The third one was greatly loaded with protein, carbohydrate, potassium, magnesium, phosphorus, calcium, vitamin C, and folate. Women in the third quintile of the first pattern were less likely to be generally obese in the fully adjusted model (odds ratio, 0.44; 95% confidence interval, 0.25-0.75). None of the other nutrient patterns had a significant association with obesity, even after adjusting for confounders. Adherence to a nutrient pattern rich in water-soluble vitamins was significantly associated with a greater chance of general obesity among women. Further studies in other populations, along with future prospective studies, are required to confirm these findings.

Association between carbohydrate quality index and general and central obesity in adults: A population-based study in Iran.

Introduction: To determine whether dietary carbohydrates quality index (CQI), glycemic index, and glycemic load is associated with general and abdominal obesity. Methods: 850 participants, 20 to 59 years old, were enrolled in a cross-sectional study from five Tehran districts through health houses. The 168 items in the semi--quantitative food frequency questionnaire were used to assess dietary intake. The CQI was calculated by using the following four components: glycemic index, total fiber, solid carbohydrate to total carbohydrate ratio, and whole grains: total grains ratio. Results: After adjusting for confounding factors, the chance of obesity in men (OR=0.38, 95% CI 0.15to 0.95; P =0.04) measured by waist circumference (WC) was significantly lower in the fourth quintile of CQI in comparison with the first quintile. In addition, OR for obesity in men (OR=2.53, 95% CI0.52 to 1.37; P =0.04) was significantly 2.5 times higher among those in the fourth quintile of glycemic index compared with those in the lowest quintile. There was no significant association between dietary carbohydrates with general obesity in men and women. Conclusion: In summary, dietary CQI is significantly inversely related to central obesity in men,according to this study. Additionally, adherence to a diet with a higher glycemic index in men is positively associated with central obesity.

Association of Nutrient Patterns with Metabolic Syndrome and Its Components in Iranian Adults.

We aimed to examine the association between nutrient patterns and metabolic syndrome (MetS) in Iranian adults. In a cross-sectional study of 850 self-certified healthy women and men aged 20-59 years old, dietary data were assessed using three 24-hour recall. Anthropometric measures were done and blood samples were collected to measure serum fasting serum glucose and lipid profile. The MetS was defined using the International Diabetes Federation. Major nutrient patterns were identified using principle competent analysis. In the first nutrient pattern, the individuals in the fifth quintile had a higher intake of vitamins B1, B2, B3, B5, B6, B12, zinc, iron, saturated fatty acids (SFAs), and protein. In the second nutrient pattern, individuals in the first quintile had lower consumption of zinc, SFAs, vitamin E, α-tocopherol, oleic acid, polyunsaturated fatty acids, ß-carotene, linolenic acid, and monounsaturated fatty acids, compared to the fifth quintile. Furthermore, in the third nutrient pattern, the individuals in the fifth quintile had a higher intake of potassium, magnesium, phosphorous, calcium, protein, carbohydrate, vitamin C, and folate compared to other quintiles. We identified the second pattern had an indirect association with systolic and diastolic blood pressure, triglycerides, fasting blood sugar (p < 0.001 for all), and total cholesterol (p = 0.04) when it was controlled for body weight. Our findings showed that nutrient patterns may have an association with MetS components with mediating body weight.

Breakfast-Based Dietary Patterns and Obesity in Tehranian Adults.

BACKGROUND: Breakfast is an important meal of the day that contributes to an overall healthy dietary pattern, better nutrient intake, and diet quality. This study sought to investigate the relationship between breakfast patterns and general and central obesity among middle-aged adults. METHODS: In this cross-sectional study of 840 apparently healthy women and men, aged 20-59 years, we assessed usual dietary intake by means of three 24-hour dietary recalls and we took anthropometric measurements. Dietary patterns were subsequently identified by factor analysis. To assess the association between breakfast composition and central and general obesity, logistic regression analysis was performed. RESULTS: We identified three major dietary patterns by factor analysis: the "bread and grains, meat products, and coffee" dietary pattern, the "sweets, tea and coffee" dietary pattern, and the "fruits, vegetables, and eggs" dietary pattern. Those people in the third tertile of the "sweets, tea and coffee" dietary category had a greater chance of having central obesity (odds ratio, 1.80; 95% confidence interval, 1.25-2.59; P=0.001). Moreover, higher adherence to the "bread and grains, meat products, and coffee" pattern increased the chance of central obesity (odds ratio, 1.67; 95% confidence interval, 1.47-1.97; P=0.03). CONCLUSION: Overall, our results suggest that specific breakfast dietary patterns are associated with increased odds of central obesity in Iranian adults.

Association of nutrient patterns and metabolic syndrome and its components in adults living in Tehran, Iran.

PURPOSE: Identification of nutrient patterns (NPs) may be helpful to evaluate the overall quality of diet and its relation to metabolic syndrome (MetS). We investigated the association of major nutrient patterns with MetS and its components among apparently healthy adults living in Tehran. METHODS: We included 522 adults (24-83 years old) who referred to health centers in Tehran. Fasting blood samples were collected to measure glycemic indicators and lipid profile. Principal component analysis (PCA) based on the 26 nutrient items were applied. Metabolic syndrome was defined based on the guidelines of the National Cholesterol Education Program Adult Treatment Panel III (ATP III). RESULTS: Three major nutrient patterns were identified: "Mono and disaccharides pattern", "Macronutrient pattern" and "Antioxidant pattern". After controlling for potential confounders, serum HDL (p < 0.001) increased across tertiles of "Antioxidant pattern". A significant inverse association was observed between adherence to "Antioxidant pattern" and odds of MetS (OR: 2.36, 95% CI: 1.51, 3.69) in crude model which was disappeared after adjusting for age, sex, education, physical activity, smoking, marital status, energy and BMI. Moreover, we found that adherence to "Antioxidant pattern" was inversely related to odds of reduced levels of serum high density lipoprotein (HDL) (OR: 0.09, 95% CI: 0.02, 0.35). No association was found between "Mono and disaccharides pattern", "Macronutrient pattern", MetS and its components. CONCLUSIONS: In general, adherence to "Antioxidant pattern "resulted in lower level of HDL concentrations. More studies are needed to investigate the possible causal relationship of these results.

The association between major dietary patterns at dinner and obesity in adults living in Tehran: A population-based study.

Introduction: Findings of studies on the association between evening meal and obesity are inconclusive. Thus, we sought to investigate the association between major dietary patterns at evening meal and obesity among apparently healthy adults in Tehran. Methods: This cross-sectional research was conducted using 833 adult men and women who lived in Tehran (age range: 20-59 years). Their dietary intake was evaluated by three, 24-h dietary recalls(24hDRs), and major patterns were identified using exploratory factor analysis. The association between major dietary patterns at dinner with general and central obesity was assessed using logistic regression analysis. Results: We identified 3 major dietary patterns at dinner including "prudent", "potatoes and eggs" and"Western" patterns. There was no significant relationship between prudent and general obesity (OR:0.76, 95% CI = 0.21, 1.15, P value = 0.20), and, a significant association was not observed between potatoes and eggs and general obesity (OR: 0.89, 95% CI = 0.60, 1.32, P value = 0.57) also, there was no significant relationship between Western dietary pattern and general obesity in this study (OR: 0.95,95% CI = 0.63, 1.43, P value = 0.82). Further analyses showed that there was no significant relationship between central obesity with any of the dietary patterns. Conclusion: The results of this study do not support a possible relationship between major dietary patterns at dinner with general and central obesity. However, the presented findings should be confirmed in prospective studies.