Comparative efficacy and safety of probiotics, prebiotics, and synbiotics for type 2 diabetes management: A systematic review and network meta-analysis.

AIMS: To compare the effects of probiotics, prebiotics, and synbiotics for type 2 diabetes (T2D) management. METHODS: We searched PubMed, Scopus, CENTRAL, and grey literature sources to December 2022 for randomized trials of the impacts of probiotics, prebiotics, or synbiotics in patients with T2D. We performed network meta-analyses with a Bayesian framework to calculate mean difference [MD] and 95 % credible interval [CrI] and rated the certainty of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. RESULTS: 68 randomised trials were included. All results are presented in comparison to the placebo. Supplementation with probiotics (MD: -0.25 %, 95%CrI: -0.42, -0.08; GRADE = moderate) and synbiotics (MD: -0.31 %, 95%CrI: -0.61, -0.04; GRADE = very low) resulted in a trivial/unimportant decrease in glycated hemoglobin. Supplementation with probiotics (MD: -0.69 mmol/L, 95%CrI: -0.98, -0.40; GRADE = very low) and synbiotics (MD: -0.82 mmol/L, 95%CrI: -1.22, -0.43; GRADE = very low) resulted in a trivial/unimportant decrease in fasting plasma glucose. Supplementation with probiotics resulted in a small but important decrease in low-density lipoprotein cholesterol (MD: -0.19 mmol/L; 95%CrI: -0.34, -0.05; GRADE = very low). Supplementations had moderate effects on serum triglyceride (GRADE = low). CONCLUSIONS: Existing evidence is uncertain and does not support supplementation with probiotics, prebiotics, and synbiotics for T2D management.

Cardiometabolic-related dietary patterns and thyroid function: a population-based cross-sectional study.

BACKGROUND: Little is known about the association of dietary patterns with thyroid function. Since thyroid function and cardiometabolic variables are inter-related, we investigated whether cardiometabolic-related dietary patterns are associated with thyroid function. METHODS: This cross-sectional study included 3520 Tehran Lipid and Glucose Study participants. Reduced rank regression was used to find dietary patterns with body mass index, serum fasting glucose, triglycerides, HDL-C, and systolic and diastolic blood pressures as response variables. Two patterns were retained, one based on 35 food groups (native-based pattern) and the other based on the European Prospective Investigation into Cancer and Nutrition Germany (EPIC) food grouping (n = 33). A confirmatory cardio-metabolic dietary pattern was also created according to the weight of food groups proposed by the Framingham Offspring Study (FOS). The association of each pattern with thyroid-stimulating hormone (TSH), free thyroxine, and thyroid peroxidase antibody (TPOAb) and the odds of thyroid dysfunction was examined by linear and logistic regression, respectively. RESULTS: The two exploratory dietary patterns were highly correlated and associated with greater TSH levels in euthyroid participants. The adjusted odds ratio (95% CI) of subclinical hypothyroidism per one standard deviation was 1.14 (1.01, 1.28) for the native-based pattern and 1.16 (1.03, 1.31) for the EPIC-based pattern. The odds of subclinical hypothyroidism was significantly greater in the second and third tertiles of the native-based pattern compared to the first tertile in the adjusted model (p-trend = 0.005). The odds of subclinical hypothyroidism increased across the tertiles of the EPIC-based pattern, but the odds was significantly higher only in tertile 3 compared to tertile 1, with an OR (95% CI) of 1.44 (1.07, 1.94) in the adjusted model. The adjusted odds of clinical hypothyroidism were greater in tertile 3 of the native-based pattern compared with tertile 1 (OR = 1.65, 95% CI 1.04, 2.62). The patterns were unrelated to hyperthyroidism or TPOAb positivity. The FOS-based confirmatory score was unrelated to thyroid function. CONCLUSIONS: A diet high in fast foods, soft drinks, and legumes and low in confectionery, potatoes, butter, and jam and honey was associated with higher TSH levels in euthyroidism and higher odds of subclinical hypothyroidism.

The combined association of dietary inflammatory index and resting metabolic rate on cardiorespiratory fitness in adults.

BACKGROUND: No study has examined the combined association of dietary inflammatory index (DII) of the diet and resting metabolic rate (RMR) on cardiorespiratory fitness (CRF). Therefore, we investigated the combined association between DII and RMR on CRF. METHODS: This cross-sectional study was conducted on 270 adult subjects. The DII was calculated using a validated semi-quantified food frequency questionnaire. RMR was measured using an indirect calorimetric method. Socioeconomic status, anthropometric measures, body composition and blood pressure were documented by a trained interviewer. CRF was assessed by using Bruce protocol. Binary logistic regression was performed to find the association of CRF with DII/RMR categories in various models. RESULTS: The participants categorized into four groups including: (1) low DII/high RMR, (2) low DII/low RMR, (3) high DII/low RMR, (4) high DII/high RMR. The mean of VO2Max (mL/kg/min), VO2max (L/min) and VO2max relative to lean body mass (LBM) was lower in participants that were classified as high DII/low RMR compared to those in low DII/high RMR. After controlling for age, sex, education status, smoking status, and physical activity those who were in the high DII/low RMR group, compared to the low DII/high RMR group were 28% less likely to have higher VO2max (ml/kg/min) (OR 0.72; 95% CI 0.18, 0.82, p = 0.04). Moreover, had 25% lower odds of VO2max (L/min) which was significant (OR 0.75, 95% CI 0.11, 0.89, p = 0.03). In addition, were 21% less likely to have higher VO2max (LBM) (OR 0.79; 95% CI 0.30, 0.92, p = 0.02). CONCLUSIONS: Overall, consumption of a pro-inflammatory diet in combination with low RMR status is associated with lower odds of CRF compared to those who had anti-inflammatory diet in combination with high RMR status among Iranian healthy adults. This study suggests that researchers should focus on combined relationships rather than single pair-wise associations for having a better judgment.

The Effects of Lycopene and Tomato Consumption on Cardiovascular Risk Factors in Adults: A Grade Assessment Systematic Review and Meta-analysis.

BACKGROUND: In recent times, modifying dietary habits to control cardiovascular risk factors has gained significant attention. However, previous studies have yielded inconsistent results regarding the effects of lycopene and tomato consumption on cardiovascular risk factors. OBJECTIVE: The objective of this study was to assess the impact of consuming lycopene and tomatoes on various cardiovascular risks factors such as lipid profile, glycemic control markers, blood pressure, inflammation, oxidative stress, and body weight. METHODS: A systematic literature search was carried out using electronic databases, including PubMed, Web of Science, and Scopus, up to November 2022 to identify eligible Randomized Control Trials (RCTs) evaluating the effect of lycopene and tomato consumption on cardiovascular risk factors. Heterogeneity tests of the selected trials were performed using the I2 statistic. Random effects models were assessed based on the heterogeneity tests, and pooled data were determined as the weighted mean difference (WMD) with a 95% confidence interval (CI). RESULTS: Out of 27,438 records initially identified, a total of 34 studies met the eligibility criteria and were included in this meta-analysis. The results showed that lycopene consumption was associated with a significant reduction in malondialdehyde (MDA) levels, indicating a potential benefit in reducing oxidative stress. However, lycopene and tomato consumption did not have significant effects on other cardiovascular risk factors such as triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), fasting blood glucose (FBG), systolic blood pressure (SBP), diastolic blood pressure (DBP), Intercellular Adhesion Molecule 1 (ICAM-1), c-reactive protein (CRP), interleukin 6 (IL-6), tumor necrosis factor α (TNF-α), body weight, and body mass index (BMI). CONCLUSION: Overall, the findings showed that lycopene and tomato consumption did not affect cardiovascular risk factors. However, lycopene supplementation may result in a significant improvement in MDA levels. With the view to confirming these results, further studies with long-term duration and different doses are needed.

Maternal uric acid levels and risk of gestational diabetes mellitus: A systematic review and dose-response meta-analysis of cohort studies including 105,380 participants.

AIMS/INTRODUCTION: Although the association between uric acid levels and adverse pregnancy outcomes has been investigated, the effects of higher uric acid levels on the risk of gestational diabetes mellitus (GDM) have yet to be established. Therefore, this systematic review and meta-analysis aimed to investigate the relationship between uric acid levels during pregnancy and the risk of GDM. MATERIALS AND METHODS: PubMed/Medline, Scopus and Web of Science databases were searched up to April 2022 for relevant observational studies. A random effects model was used to estimate pooled odds ratios (OR) and 95% confidence intervals (95% CI). To assess the heterogeneity of included studies, the I2 index was used. RESULTS: Among the initial 262 studies that were recognized from the databases search, 23 studies including 105,380 participants were eligible. Pooled analysis showed that higher uric acid levels significantly affected the risk of GDM (OR 2.58, 95% CI 1.89-3.52, I2 = 90.8%, P < 0.001). Subgroup analyses based on the gestational week showed that higher uric acid levels before the 20th week of gestation were significantly associated with the risk of GDM (OR 3.26, 95% CI 2.26-4.71, I2 = 89.3%, P < 0.001). Based on the meta-regression analysis, uric acid levels and odds of GDM were significantly correlated with the participants' age, and it was more significant in younger pregnant women. CONCLUSIONS: This study showed a positive association between uric acid levels and the risk of GDM. Also, our results indicate that measuring uric acid levels before 20 weeks of gestation can potentially predict GDM, especially in younger women.

Interaction of dietary acid load and general and central obesity with muscle strength and skeletal muscle mass.

BACKGROUND: We aimed to examine the combined association of dietary acid load and obesity with muscle strength. METHODS: This cross-sectional study was conducted on 270 adults (118 men and 152 women), aged 18-70 y. Dietary data were collected using a validated 168-item semi-quantitative food frequency questionnaire. Potential renal acid load (PRAL), net endogenous acid production (NEAP), and dietary acid load (DAL) were calculated. General obesity was defined as a body mass index (BMI) ≥30 kg/m2 and abdominal obesity was defined as a waist circumference (WC) ≥102 cm for men and ≥88 cm for women. Muscle strength was measured by a digital handgrip dynamometer. RESULTS: The mean of muscle strength was higher in participants classified as high-PRAL/BMI≥30 (P = 0.01), high-PRAL/WC < 102 (men) or 88 (women) (P = 0.002), high-NEAP/BMI≥30 (P = 0.002), high-NEAP/WC < 102 (men) or 88 (women) (P < 0.001) and also high-DAL/BMI≥30 (P = 0.01) and high-DAL/WC < 102 (men) or 88 (women) (P = 0.001) compare to other classifications in the crude model. Both for obese and non-obese people PRAL, NEAP, and DAL were associated with higher muscle strength, which is opposite to the acid hypothesis. These associations were not significant after adjustment for confounders. Also, the mean of skeletal muscle mass was higher in participants that were classified as high-PRAL/BMI≥30 and high-PRAL/WC < 102 (men)-or-88 (women), high-NEAP/BMI≥30, and high-NEAP/WC < 102 (men)-or-88 (women), high-DAL/BMI≥30 and high-DAL/WC < 102 (men)-or-88 (women) (Ptrend<0.001 for all). These significant associations remained significant after controlling for confounders. CONCLUSIONS: We found that the interaction of dietary acid load and general and central obesity could be associated with skeletal muscle mass but not muscle strength. All findings of association indicated higher muscle strength and skeletal muscle mass with higher acid diet measures, contrary to the acid hypothesis.

The low-carbohydrate-diet score is associated with resting metabolic rate: an epidemiologic study among Iranian adults.

PURPOSE: Low-carbohydrate diet (LCD) has been used for weight loss and preventing obesity, but the association of adherence to LCD and resting metabolic rate (RMR) has not been investigated. This study aimed to investigate the association between the low-carbohydrate-diet score (LCDS) and RMR among Iranian adults. METHODS: This cross-sectional study was conducted on 270 Iranian adults 18-70 y of age. To assess dietary intakes, participants completed a validated food frequency questionnaire. The LCDS was calculated based on carbohydrate, protein and fat intake, expressed as a percentage of energy. The higher score indicates the lower carbohydrate and the higher protein and fat intake. RMR was measured by indirect calorimetry after an overnight fast. RESULTS: Multivariate-adjusted means showed that RMR significantly increased across tertiles (p = 0.041). However, there were no significant differences in the mean of fat mass (FM) and fat-free mass (FFM) across tertiles of LCDS (p = 0.986 and p = 0.621, respectively). Also LCDS and RMR (r = 0.14, p = 0.021) were found to be correlated, but LCDS and FFM (r = 0.06, p = 0.323), FM (r = -0.05, p = 0.412), had no statistically significant correlation. RMR had a significant positive association with LCDs in the crude model (ß = 18.81, 95% CI: 2.55, 35.07, P = 0.024). Moreover, after controlling for covariates this association changed to non-significant (ß = -0.14, 95% CI: -7.05, 19.25, P = 0.03). CONCLUSION: Adherence to diets lower in carbohydrates and higher in fat and protein were associated with higher RMR. Further studies with a larger sample size are needed to confirm these findings.

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.

Higher health literacy score is associated with better healthy eating index in Iranian adults.

OBJECTIVE: Although there is some evidence for the importance of health literacy (HL), many health complications and nutrition knowledges such as portion size assessment, knowing the food labels, and choosing the nutrition sources affecting diet quality, data about HL and healthy eating index (HEI) are limited and controversial. The aim of this study was to evaluate the associations between HL and HEI in adults. METHODS: This cross-sectional study included 261 adults 18 to 65 y of age from five districts of Tehran, Iran. HL was estimated using the Health Literacy for Iranian Adult (HELIA) questionnaire. Dietary intake, sociodemographic data, physical activity, and anthropometric measurements were collected using validated questionnaires. Diet quality was assessed based on HEI-2015 scores using data from a food frequency questionnaire. RESULTS: Despite components of HEI-2015, the association between HEI-2015 and HL tertiles was significant (P of crude model = 0.007) even after adjustment for possible confounders. Multivariate regression showed a positive relationship between HL and HEI-2015 that was significant before (ß = 0.12, P = 0.04) and after controlling for the confounding effect in model 1 (ß = 0.14, P = 0.03). Additionally, a positive association between physical activity and HL was shown (ß = 0.12, P = 0.03) and finally among the HEI components, only saturated fats were significantly related to HL (ß = -0.11, P = 0.01). CONCLUSION: Findings from the present study confirmed a considerable association between HL and HEI and shows HL levels have an important role in adherence to the Iranian Dietary Guidelines.

Higher dietary insulin load and index are not associated with the risk of metabolic syndrome and obesity in Iranian adults.

BACKGROUND: Data about the relation between dietary insulin load (DIL) and dietary insulin index (DII) with metabolic syndrome (MetS) and obesity are scarce. Therefore, the present study aimed to examine the association of the insulinemic potential of the diet with MetS and obesity amongst Iranian adults. METHODS: This cross-sectional study was conducted amongst 850 adults aged 20-59 years. Dietary data were collected using a 168-item food frequency questionnaire. DIL was calculated using a standard formula and DII was obtained by dividing DIL by the total energy intake of each participant. The guidelines of the International Diabetes Federation were used to define MetS. General obesity was considered as body mass index ≥ 30 kg/m2 , and abdominal obesity as waist circumference ≥ 94 cm for men and ≥ 80 cm for women. RESULTS: Mean DIL and DII values were 101 684 ± 54 802 and 49.4 ± 33.4, respectively. The mean age of participants was 44.9 ± 10.7 years and 36.8%, 28.5% and 48.8% of participants were suffering from MetS, general and abdominal obesity, respectively. In contrast with DIL (P = .73), participants in the last quartile of DII (P = .62) had lower odds of MetS than the first quartile. There were non-significant inverse associations between DIL (P = .91, P = .85) and DII (P = .59, P = .53) with odds of general and abdominal obesity before and after the adjustment of confounders, respectively. CONCLUSIONS: We did not observe any significant association of DIL and DII with the risk of MetS and obesity amongst the Iranian population. Further prospective studies are needed to confirm the findings of this study.

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.

Associations between adherence to MIND diet and metabolic syndrome and general and abdominal obesity: a cross-sectional study.

BACKGROUND: There is a lack of studies examining the association between Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) and metabolic syndrome (MetS) and obesity. Thus, this study aimed to investigate the association of adherence to the MIND diet with MetS and general and abdominal obesity. METHODS: This cross-sectional study was performed on 836 Iranian adults, 18-75 years old. A 167-item food frequency questionnaire (FFQ) was used to assess dietary intakes of participants. Anthropometric measurements, blood pressure, fasting blood glucose and lipid profile of each participant were recorded. The guidelines of the National Cholesterol Education Program Adult Treatment Panel III (ATP III) was used to define MetS. RESULTS: Mean age of study participants was 47.7 ± 10.7 years. The prevalence of MetS was 36.1% and mean body mass index (BMI) and waist circumference (WC) was 27.7 ± 4.69 kg/m2 and 92.0 ± 12.4 cm respectively. Those who were in the third tertile of the MIND diet score compared to the first tertile had 12% lower odds of having the MetS (ORs: 0.88; 95% CI 0.62-1.24) but the association was not significant (P = 0.77). There was a significant inverse association between the MIND diet score and odds of reduced high-density lipoprotein cholesterol (HDL-C) (ORs: 0.59; 95% CI 0.41-0.85; P = 0.008) and general obesity (ORs: 1.190.80-1.78; 95% CI 0.80-1.78; P = 0.02) in crude model and after controlling for confounders. CONCLUSIONS: We found that the MIND diet score is inversely associated with odds of reduced HDL and general obesity in Iranian adults.

Effects of melatonin supplementation on oxidative stress: a systematic review and meta-analysis of randomized controlled trials.

OBJECTIVES: Previous studies showed that melatonin supplementation may suppress oxidative stress, however, the results have not been consistent. So, we conducted this meta-analysis to assess the precise relationship between melatonin supplementation and oxidative stress. METHODS: PubMed and Scopus were searched for randomized controlled trials that investigated the effect of melatonin supplementation on oxidative stress up to March 2020. Heterogeneity was assessed by Cochran's Q test and I-square (I 2) statistic. Data were pooled using the random effect model and standardized mean difference (SMD) was considered as the summary effect size. Also, standard methods were used for assessment of sensitivity analysis and publication bias. RESULTS: We included 15 related articles and our findings indicated that melatonin supplementation significantly increased total antioxidant capacity (TAC) level (SMD: 1.03, 95% CI: 0.24, 1.81, p=0.011) and reduced protein carbonyl (PCO) (SMD: -1.78, 95% CI: -2.97, -0.58, p=0.004) and malondialdehyde (MDA) levels (SMD: -0.94, 95% CI: -1.48, -0.40, p=0.001). Additionally, there was considerable effect on TAC level by using ≥20 mg/d melatonin and in people under 35 years old. MDA level also decreased using dosage of below 20 mg/d and in people ≥35 years old. CONCLUSIONS: The present study showed a promising effect of melatonin administration for reducing MDA, PCO, and increasing TAC levels. However, further studies especially with more attention to PCO level assessment are needed to confirm the findings of the present study in larger samples on different populations.

Dietary Total Antioxidant Capacity and Its Association with Renal Function and Progression of Chronic Kidney Disease in Older Adults: a Report from a Developing Country.

While evidence exists for an association between the dietary total antioxidant capacity (DTAC), mortality, metabolic syndrome, and cardiovascular diseases, data about DTAC and renal function, and progression of chronic kidney disease (CKD) are scarce. This study aimed to determine the associations between DTAC, renal function, and progression of CKD in older adults. The present cross-sectional study consisted of 226 older adults aged ≥ 60 years old from five districts of Tehran, Iran. DTAC was estimated using the oxygen radical absorbance capacity (ORAC) method. Dietary intake, socio-demographic data, medical history, and anthropometric measurements were collected using a validated questionnaire. The estimated glomerular filtration rate (eGFR) was assessed from serum creatinine. Albumin to creatinine ratio (ACR) was calculated by dividing albumin concentration by creatinine concentration and reported as mg/g. The DTAC ranged from 112.8 to 2,553.9. Analyses indicated that DTAC was not associated with eGFR (p = 0.35) and ACR (p = 0.91) even after controlling for confounding variables. Additionally, in logistic regression, no association between eGFR < 60 mL/min/1.73 m2 (p = 0.32) and ACR ≥ 30 mg/g (p = 0.32) with DTAC was observed, which was independent of confounding variables. We observed that more compliance with DTAC is not associated with renal function and CKD progression. Further studies are needed to confirm the findings of the present study in larger samples on different populations.

The association between dietary acid load and muscle strength among Iranian adults.

OBJECTIVE: There is limited evidence regarding the association between dietary acid load and muscle strength. Thus, in this study, we investigated the association between dietary acid-base load indices and muscle strength among Iranian adults. RESULTS: This cross-sectional study was conducted on 270 Iranian adults, aged 18-70 year. Dietary acid load indexes, were calculated by using a validated 168-item semi-quantitative food frequency questionnaire (FFQ). Muscle strength was measured by a digital handgrip dynamometer. There was a significant increase in mean muscle strength of left-hand (MSL), muscle strength of right-hand (MSR) and the mean of the MSL and MSR (MMS) across tertiles of Potential Renal Acid Load (PRAL), Net Endogenous Acid Production (NEAP), and Dietary Acid Load (DAL). Significant linear relationships between PRAL and; MSL (ß = 0.24, p < 0.001), MSR (ß = 0.23, p < 0.001) and MMS (ß = 0.24, p < 0.001), between NEAP and MSL (ß = 0.21, p < 0.001), MSR (ß = 0.19, p = 0.002), and MMS (ß = 0.20, p = 0.001) and between DAL and MSL (ß = 0.25, p < 0.001), MSR (ß = 0.23, p < 0.001) and MMS (ß = 0.24, p < 0.001), were attenuated after controlling for potential confounders. However, the nonlinear relationship between dietary acid load indicators and muscle strength were significant (p < 0.001 for all).

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.

The association between healthy lifestyle score with cardiorespiratory fitness and muscle strength.

OBJECTIVE: The association of individual behaviours such as diet, tobacco use, body mass index (BMI) and physical activity have been investigated separately in relevance to cardiorespiratory fitness (CRF) and muscle strength. The purpose of this study is to investigate the combined association of the four mentioned lifestyle factors with cardiorespiratory fitness and muscle strength. METHODS: This cross-sectional study was conducted on 271 Iranian adults, aged 18-70 years. We developed a healthy lifestyle score (HLS) that ranged from 0 to 103 (higher score reflecting better adherence to healthier lifestyle) and included four lifestyle behavioural components (diet, physical activity, smoking and BMI). The relationship between HLS, CRF and muscle strength was determined using linear and non-linear regression analysis. RESULTS: HLS score was not significantly associated with VO2max (mL/kg/min) P = .43; VO2max (L min) P = .14; VO2max (LBM) (P = .79) and mean muscle strength (MMS) (kg) (P = .11), muscle strength of right hand (MSR) (kg) (P = .10) and muscle strength of left hand (MSL) (kg) (P = .16) in the unadjusted model. After adjustment for potential confounders, we found a significant association between HLS and Vo2max (L/min), MMS (kg), MSR (kg) and MSL (kg) (P < .001 for all). Also HLS and MMS (r = .06, P = .31), MSR (r = .07, P = .25), MMS (r = .05, P = .39), VO2max (mL/kg/min) (r = .01, P = .77), VO2max (L min) (r = .05, P = .35) and VO2max (LBM) (r = .002, P = .91) have no statistically significant linear relationship. CONCLUSION: Adherence to healthy lifestyle may be associated with increased CRF and muscle strength after adjusting for potential confounding variables.