Joint association of meal frequency and diet quality with metabolic syndrome in Iranian adults

Scoping review protocol: The chrononutrition factors in association with glycemic outcomes in adult population

Chrononutrition, which examines the relationship between circadian rhythms and nutrition, has been associated with glycemic outcomes in adults. However, published data on delayed meal timing, increased meal frequency and frequent breakfast skipping have shown inconsistent glycemic outcomes due to variations in methodologies and populations studied. This review presents the scoping review protocol designed to map the evidence on the association between chrononutrition factors and glycemic outcomes in adults. The methodology framework from Arksey and O'Malley will be adapted for this scoping review. Relevant publications will be searched on databases including PubMed, EBSCO Host, ProQuest Central, MEDLINE & Ovid, Scopus and Web of Science. This review focuses on original articles published from January 2014 to 2024, involving participants aged 18 years and older, published in English, and encompassing experimental and observational studies. A comprehensive keyword search strategy will be developed to identify relevant articles. Two reviewers will independently screen the abstracts and titles to determine the eligibility. Subsequently, the full text of potentially eligible articles will be reviewed by additional independent reviewer for final inclusion, with full text screening being verified by two reviewers, and interrater reliability will be conducted. Data from the included articles will be extracted, collated and charted to summarize the relevant methods, outcomes and key findings. This Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) checklist will be used to guide the development of protocol. This scoping review represents a novel approach to summarize the association between chrononutrition factors and glycemic outcomes among adults. We anticipate the findings of the review will provide stakeholder with crucial evidence-based information for development of effective intervention to manage glycemic outcome in adults. This protocol has been prospectively registered in the Open Science Framework (https://doi.org/10.17605/OSF.IO/PA9BU).

Scoping review: Exploring the relationship between chrononutrition and glycemic responses in the adult population

Chrononutrition, an emerging body of evidence on the relationship between biological rhythms and metabolism, has been established to be associated with glycemic responses. However, the available evidence is inconsistent, due to protocol variations. Therefore, this review aims to summarize the findings on chrononutrition characteristics and their association with glycemic responses among adults. Systematic searches were conducted across six databases (PubMed, EBSCO Host, ProQuest Central, MEDLINE & Ovid, Scopus and Web of Science) to identify all relevant studies published from January 2012. Two reviewers independently screened the abstracts and full-text articles based on the inclusion and exclusion criteria. Details about population characteristics, study methods and key findings were extracted following the PRISMA-ScR guideline. The quality of selected studies was evaluated using the mixed methods appraisal tool. The searchers identified 49 studies eligible for analysis. The results showed that meal timing, particularly night-time eating and snacking were associated with glycemic responses. Regarding meal regularity, skipping breakfast may affect glycemic responses, but no clear conclusion was drawn about its effect on insulin. The association between meal frequency and glycemic responses was inconclusive. Night fasting duration and restricted eating window are potentially associated with glycemic responses. The current review extensively investigates the association between chrononutrition factors and glycemic responses in adults. However, more prospective cohort and interventional studies are needed to better understand this causal-effect relationship.

Association of meal-specific protein intake and cardiometabolic risk factors: a cross-sectional study

We aimed to investigate the association of main meals' specific protein intake with cardiometabolic risk factors, including general and abdominal obesity, serum lipid profile, and blood pressure (BP). This cross-sectional study was conducted on 850 subjects aged 20-59 years. Dietary intakes were assessed by completing three 24-h recalls, and the protein intake of each meal was extracted. Anthropometric measures, lipid profile, fasting blood sugar and BP were measured. Multivariate logistic regression controlling for age, physical activity, sex, marital status, smoking status, BMI and energy intake was applied to obtain OR and CI. The mean age was 42 years, and the mean BMI of the participants was 27·2. The mean protein intake for breakfast, lunch and dinner was 12·5, 22·2 and 18·7 g/d, respectively. After adjustment for confounders, higher protein intake was not associated with any of the cardiometabolic risk factors, including LDL-cholesterol, HDL-cholesterol, total cholesterol (TC), TAG, body weight, BP and fasting plasma glucose, in any of the three main meals consumed within a day. Adherence to a higher protein intake at each meal was not associated with cardiometabolic risk factors in Iranian adults. Further prospective studies are needed to justify our findings.

Diet diversity and food quality score in male football players and healthy non-athlete controls in relation to oxidative stress biomarkers: a descriptive-analytical study

BACKGROUND

Dietary patterns that include high-quality and varied food groups have the potential to modulate oxidative status. This research was conducted to determine dietary diversity score (DDS) and food quality score (FQS) in football players and their matched non-athletes, also their associations with oxidative indicators assessed by the urinary levels of F2alpha-isoprostane (F2a-IP) and 8-hydroxy-2'-deoxyguanosine (8-OHdG).

METHODS

Participants consisted of 45 male football players and 45 male non-athletes in two age-and body mass index (BMI)-matched groups from Shiraz City, Iran. Anthropometric measurements were performed, and urine samples were analyzed to determine oxidative biomarkers. Dietary data derived from a reliable food frequency questionnaire with 168 items was completed to determine DDS and FQS. For data analysis, an appropriate generalized estimating equation model was set up.

RESULTS

Our results demonstrated that FQS (β = 5.46; P < 0.001) and DDS (β = 1.30; P < 0.001) scores were significantly higher in the footballers in comparison to the non-athletes. Moreover, FQS was negatively associated with 8-OHdG (β=-0.35; P = 0.008) and F2a-IP (β=-4.30; P = 0.01) levels in all participants. In addition, DDS was inversely related to 8-OHdG (β=-1.25; P = 0.01) and F2a-IP (β=-11.67; P = 0.04) levels in all participants.

CONCLUSIONS

Food quality scores and dietary diversity of footballers' diets were found to be higher in comparison to the non-athletes. Furthermore, a higher FQS and DDS were associated with lower levels of oxidative biomarkers in all participants.

Quality of diet and odds of metabolic syndrome in Iranian adults: Baseline results from the PERSIAN Kavar cohort study (PKCS)

BACKGROUND AND AIMS

Metabolic Syndrome (MetS) is a major risk factor for cardiovascular diseases and type 2 diabetes mellitus. Diet quality has been associated with multiple chronic diseases. We aimed to investigate the association between the quality of diet and the odds of being diagnosed with MetS.

METHODS AND RESULTS

This study was conducted cross-sectionally on baseline data of 2225 individuals from the PERSIAN Kavar Cohort Study (PKCS). The quality of diet was measured based on the Diet Quality Index - International (DQI-I), using Food Frequency Questionnaires. The association between DQI-I and MetS and its components was measured via logistic regression models in crude and adjusted models. We did not observe any association between DQI-I and MetS in the overall population. However, after adjustment for potential confounders, we found that male participants with higher DQI-I scores had a lower risk of MetS [adjusted odds ratio (OR) 95% confidence interval CI) = 0.62 (0.42-0.93)]. Moreover, analogous trends were observed with respect to some components of MetS, including elevated triglyceride (TG) [crude OR (95% CI) = 0.89 (0.70-0.98); adjusted OR = 0.82 (0.65-0.93)], lowered high-density lipoprotein cholesterol (HDL-c) [crude OR (95% CI) = 0.79 (0.57-0.99); adjusted OR = 0.76 (0.55-0.97)], and abnormal glucose homeostasis [crude OR (95% CI) = 0.80 (0.55-0.94); adjusted OR = 0.73 (0.51-0.91)] only in male participants, both before and after adjustment for potential confounders.

CONCLUSION

In this study, we showed that higher adherence to a high-quality diet was associated with a lower chance of developing MetS in men. Biological gender might be responsible for the observed discrepancies.

Association of main meal quality index with the odds of metabolic syndrome in Iranian adults: a cross-sectional study

BACKGROUND

Metabolic syndrome (MetS) is a common global issue linked to the quality of one's eating occasions. The current cross-sectional study evaluates the association between a novel index, the Main Meal Quality Index (MMQI), and MetS among Iranian adults.

METHODS

A total of 824 men and women were recruited, and a 24-hour dietary recall assessed the dietary intake of the participants. Lunch was selected as the main meal based on energy density. The MMQI score was calculated based on ten components of dietary intake, with a higher score indicating more adherence to the index, with the final scores ranging from 0 to 100 points. The associations were assessed using binary logistic regression.

RESULTS

The mean age was 42.2 years and the range of the calculated MMQI was 22 to 86 (mean in total participants: 56.62, mean in women: 56.82, mean in men: 55.64). The total prevalence of MetS in the sample was 34%. After adjustments for potential confounders, the participants at the top quartile of MMQI had a lower odds ratio for hypertriglyceridemia and low high-density lipoprotein (HDL) level, and a higher odds ratio for hypertension, hyperglycemia, abdominal obesity, and MetS. The sex-specific analysis also did not show any significant associations between adherence to MMQI and MetS and its components.

CONCLUSION

Overall, MMQI is not associated with MetS and its components in a sample of Iranian men and women. More research is needed to examine MMQI and its possible association with current health-related problems including MetS.

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

OBJECTIVE

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

DESIGN

Cross-sectional, nationally representative surveys.

SETTING

Colombia.

PARTICIPANTS

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

MAIN OUTCOMES AND MEASURES

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

RESULTS

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

CONCLUSIONS

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

Lifestyle Factors Associated with Metabolic Syndrome in Urban Cambodia

This study aimed to identify lifestyle factors associated with metabolic syndrome (MetS) in urban Cambodia. In this cross-sectional study, we used existing health checkup data from a private hospital in Phnom Penh, Cambodia. The participants comprised 5459 Cambodians aged ≥20 years who underwent health checkups between 2017 and 2019. The harmonized diagnostic definition was used as the MetS criteria. The prevalence of MetS was 56.6% overall, 60.4% in men and 52.6% in women. The lifestyle factor significantly associated with MetS in both sexes were "eating quicker than others", (men: odds ratio [OR]= 2.25, 95% confidence interval [CI] = 1.68-3.03, women: OR = 1.92, 95%CI = 1.41-2.60), "walking faster than others", (men: OR = 0.78, 95% CI = 0.67-0.92, women: OR = 0.75, 95% CI = 0.62-0.89) and "drinking alcohol" (men: OR = 1.33, 95% CI = 1.10-1.61, women: OR = 1.33, 95% CI = 1.09-1.62). Other significant associations with MetS for men was "eating speed is normal", (OR = 1.73, 95%CI = 1.30-2.31), and, for women, "eating food after dinner at least 3 days a week", (OR = 1.25, 95%CI = 1.01-1.55), "skipping breakfast at least 3 days a week", (OR = 0.83, 95%CI = 0.69-0.99) and "getting enough rest from sleep" (OR = 1.19, 95% CI = 1.01-1.42) were significantly associated with MetS. Lifestyle interventions through health education and guidance may be effective in preventing MetS in Cambodia.