Low-carbohydrate-diet score and metabolic syndrome: An epidemiologic study among Iranian women

Association of low-carbohydrate diet scores and type 2 diabetes in Chinese rural adults: The Henan Rural Cohort Study

PURPOSE

To investigate the association between low-carbohydrate diet scores (LCDs) and the risk of type 2 diabetes in rural China.

METHODS

A total of 38,100 adults were included in the Henan Rural Cohort Study. Macronutrient intake was assessed via a validated food-frequency questionnaire to create low-carbohydrate diet (LCD) scores. Multivariate logistic regression models and subgroup analysis were performed to estimate the odds ratio (OR) and 95% confidence interval (95% CI).

RESULTS

After multivariable adjustment, participants with a high total low-carbohydrate diet score have a high risk of T2D (extreme-quartile OR = 1.23, 95% CI: 1.04-1.41; P = 0.007), whereas plant-based LCD score is not related to T2D risk. Among individuals with a BMI < 24 (extreme-quartile OR = 1.22, 95% CI: 1.01-1.47; P < 0.001) or high levels of physical activity (extreme-quartile OR = 1.42, 95% CI: 1.17-1.72; P < 0.001), the animal-based LCD score is positively correlated with the risk of T2D.

CONCLUSION

Among Chinese rural populations, high-fat-low carbohydrate diet is associated with an increased risk of type 2 diabetes. High intake of animal protein and fat also increases T2D risk in those who are overweight or have high physical activity.

Association between adherence to a low carbohydrate dietary (LCD) pattern with breast milk characteristics and oxidative markers in infants' urine: a cross-sectional study

BACKGROUND

Breast milk (BM) is a dynamic fluid that varies over time and between women. The variations in BM components are most likely associated with maternal diet quality. This study aimed to assess adherence to a low carbohydrate dietary (LCD) pattern with oxidative stress markers of BM characteristics and infants' urine.

MATERIALS AND METHODS

In this cross-sectional study 350 breastfeeding mothers and their infants were recruited. BM samples were collected from mothers, and urine specimens were obtained from each infant. To evaluate LCD scores, subjects were divided into 10 deciles according to the percent of energy obtained from carbohydrates, proteins, and fats. Determination of total antioxidant activity was conducted using the ferric reducing antioxidant power (FRAP), 2, 2'-diphenyl-1-picrylhydrazyl (DPPH), thiobarbituric acid reactive substances (TBARs), and Ellman's assay. Biochemical assays of samples including calcium, total protein, and triglyceride level were also performed using commercial kits.

RESULTS

Participants with the greatest LCD pattern adherence were placed into the last quartile (Q4), and those with the minimum LCD were in the first quartile (Q1). Individuals in the highest LCD quartile had significantly higher levels of milk FRAP, thiol, and protein, as well as infant urinary FRAP and lower milk MDA levels than those in the lowest quartile. Multivariate linear regression analyses indicated that higher score of the LCD pattern was associated with a higher level of milk thiol, protein, and lower level of milk MDA (p < 0.05).

CONCLUSION

Our findings show that adherence to a LCD, as defined by a low level of carbohydrates in daily food intake, is linked with improved BM quality and markers of oxidative stress in infant urine.

The association between a low-carbohydrate diet score and the risk of diabetic nephropathy in women: A case-control study

OBJECTIVES

Because evidence linking carbohydrate consumption to diabetic nephropathy (DN) is scarce, and the association between a low-carbohydrate diet (LCD) and DN has not been investigated, we sought to investigate whether a higher LCD score is associated with DN among women.

METHODS

In a case-control study, 105 women with type 2 diabetes mellitus and DN and 105 controls with type 2 diabetes mellitus and without DN who attended Kowsar Diabetes Clinic in Semnan, Iran, were matched for age and diabetes duration. The data related to anthropometric and biochemical measures were collected and a food frequency questionnaire with 147 items was used to assess dietary intake. Based on the food frequency questionnaire, we calculated an LCD score for each study participant. Multivariate logistic regression was performed to examine the association between an LCD score and the odds of developing DN.

RESULTS

The results of the study demonstrated that the LCD score was not significantly associated with DN in the crude model (odds ratio = 0.39; 95% confidence interval, 0.14-1.07; P = 0.06). However, after adjusting for several confounders, subjects in the top quartile of the LCD score were associated with a 71% lower risk of DN (odds ratio [OR] = 0.29; 95% confidence interval, 0.10-0.86; P = 0.02). A significant trend toward decreased urinary albumin excretion was found with an increase in the LCD score (P = 0.005).

CONCLUSIONS

A diet low in carbohydrates was inversely associated with risk of DN. Further observational studies, and preferably randomized controlled trials, are needed to confirm the present results.

The relationship between low-carbohydrate diet score, dietary insulin index and load with obesity in healthy adults

PURPOSE

Carbohydrate intake and insulinemic potential of diet are suggested to be correlated with the development of different chronic diseases. Considering the limited research on obesity, this study aimed to investigate the association of dietary insulin index (DII), dietary insulin load (DIL), and low-carbohydrate diet score (LCDS) with body weight and obesity in healthy adults.

METHODS

In this cross-sectional study, DII, DIL, and LCDS were calculated using relevant formulas based on dietary intakes obtained by a valid 168-item food frequency questionnaire, in 393 otherwise healthy adults of either normal-weight, overweight, or obese.

RESULTS

Individuals in the highest tertile of DIL and DII had respectively 73% (OR: 0.27, 95% CI 0.08-0.94, p = 0.049) and 50% (OR: 0.5, 95% CI 0.26-0.96, p = 0.038) lower odds of being overweight compared to the lowest tertile, after adjusting the effects of age, sex, and dietary energy intake. Participants in the highest tertile of DIL had 92% greater odds of being obese compared to the lowest tertile, but this association did not remain significant after adjusting the effect of energy intake. Individuals in the highest tertile of LCDS had about 2 times odds of being overweight compared with those in the lowest tertile (OR: 2.04, 95% CI 1.04-4.01, p = 0.049). There was no relationship between being obese and tertiles of LCDS.

CONCLUSION

Higher dietary carbohydrate intake and insulinemic potential of diet could not be considered independent dietary risk factors for overweight or obesity.

LEVEL OF EVIDENCE

Level III: evidence obtained from an observational study.

Adherence to low carbohydrate diets and non-alcoholic fatty liver disease: a case control study

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is defined as the excessive accumulation of fat in the liver cells of people who do not drink alcohol. The aim of study is investigated the association between low carbohydrate diets (LCDs) and NAFLD.

METHODS

This age and gender-matched case-control study was conducted on 120 patients newly diagnosed with NAFLD and 120 adults without NAFLD. Diagnosis of NAFLD based on laboratory tests and abdominal ultrasound. Low carbohydrate diets score calculated on the percentage of energy as carbohydrate, fat, and protein. Participants in the highest rank intake of fat and protein and lowest intake of carbohydrate received 10 points. Multivariable logistic odds ratio was used for examine the relation between LCDs and NAFLD.

RESULTS

This study showed subjects in the highest tertile of LCD has more intake of zinc and vitamin B12 compare to lowest. Also, intake of protein (p = 0.02) carbohydrate (p < 0.02) and cholesterol (p = 0.02) were significantly higher in patient with NAFLD compare to control subjects. There was no significant association between LCD and risk of NAFLD (OR: 1.36; 95% CI: 0.97-1.92; P-trend = 0.13) in crude and adjusted (OR: 1.31; 95% CI: 0.84-2.04; P-trend = 0.23) model.

CONCLUSION

However, we showed that intake of protein, carbohydrate and cholesterol are higher in NAFLD, but our results of study showed that LCDs with higher proportion intakes of protein and fat was not associated with NAFLD. Further prospective studies are required for confirm these associations.

The association between low carbohydrate diet scores and cardiometabolic risk factors in Chinese adults

Epidemiological studies on the association between the low carbohydrate diet (LCD) score and cardiovascular disease risk factors have limited and inconsistent results. Data are from the baseline survey of Community-based Cohort Study on Nervous System Diseases. A total of 4609 adults aged ≥18 years were included in the study. Dietary data were assessed using a validated semi-quantitative Food Frequency Questionnaire. Multivariable logistic regression analyses were used to estimate relationships of three LCD scores with low high-density lipoprotein cholesterol (HDL-C), high low-density lipoprotein cholesterol (LDL-C), hypercholesterolemia, hypertriglyceridemia, impaired fasting glucose (IFG), high blood pressure, and hyperuricemia after adjusting for potential confounders. A higher LCD score was negatively associated with low HDL-C [OR (95%CI): 0.65 (0.50, 0.83), P=0.0001] and IFG [OR (95%CI): 0.65 (0.51, 0.81), P=0.001] after the final adjustment. However, there are gender differences in this result. Males in the highest quintile of the animal-based or plant-based LCD scores showed a decreased risk of low HDL-C, and females in the highest quintile of the animal-based or plant-based LCD scores showed a decreased risk of IFG than those in the lowest quintile of the LCD scores. These results suggest that gender differences should be considered when using LCD to treat dyslipidemia and reduce fasting blood glucose.

The Association Between Low Carbohydrate Diet and Resting Metabolic Rate in Overweight and Obese Women: A Cross-Sectional Study

Resting metabolic rate (RMR) accounts for most daily energy expenditure. The low carbohydrate diet (LCD) attenuates decreases in RMR. This study aims to investigate the relationship between an LCD and RMR status among overweight and obese women. We enrolled 291 overweight and obese women in this cross-sectional study. Body mass index (BMI), fat mass, fat-free mass, visceral fat, and insulin level were assessed. RMR was measured using indirect calorimetry. LCD score (LCDS) was measured using a validated semi-quantitative food frequency questionnaire. Analysis of variance, independent sample t-test, and Multinomial logistic regression tests were used. Results showed no relationship between LCDS and deviation of normal RMR (DNR) even after adjust for confounders (increased [Inc.] RMR: odds ratio [OR], 0.97; 95% confidence interval [CI], 0.92–1.01; p = 0.20; decreased [Dec.] RMR: OR, 0.97; 95% CI, 0.94–1.00; p = 0.14). Some components of LCDS had no significant association with DNR, such as carbohydrate and Dec. RMR in adjusted model (OR, 1.62; 95% CI, 0.98–1.37; p = 0.08) and monounsaturated fatty acids and Dec. RMR in adjusted model (OR, 0.48; 95% CI, 0.21–1.10, p = 0.08). However, refined grains had a significant association with Inc. RMR in crude model (OR, 0.87; 95% CI, 0.77–0.99, p = 0.04). There is no association between LCDS and RMR status.

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.

The association between low-carbohydrate diet score and metabolic syndrome among Iranian adults

OBJECTIVE

Assessing the relationship between low-carbohydrate diet (LCD) score and metabolic syndrome (Mets) in Iranian adults.

DESIGN

Cross-sectional study.

SETTING

Yazd Health Study and Taghzieh Mardom-e-Yazd study.

PARTICIPANTS

Data of 2074 participants were used. Dietary intakes were assessed by a validated semi-quantitative FFQ. LCD score was calculated for each person by summing up the assigned scores to deciles of energy percentages from macronutrients. Mets was evaluated using National Cholesterol Education Program Adult Treatment Panel III. Eventually, association between LCD score and Mets was examined using logistic regression.

RESULTS

Total Mets prevalence was approximately 40·5 %. After adjustment for confounders, subjects in the higher quartile of LCD score had a significant lower chance of Mets than lower quartile among all participants (Q4 v. Q1: OR: 0·68, 95 % CI (0·50, 0·92)) and separately in men (Q4 v. Q1: OR: 0·54, 95 % CI (0·34, 0·86)) and women (Q2 v. Q1: OR: 0·53, 95 % CI (0·34, 0·82)). Furthermore, more LCD adherence in men reduced abdominal obesity by 47 % (Q3 v. Q1: OR: 0·53, 95 % CI (0·28, 0·99)). A significant inverse relation was also observed between low HDL cholesterol and LCD score in all participants (Q4 versus Q1 OR: 0·74, 95% CI: 0·56-0·99) and separately in men (Q4 versus Q1 OR: 0·63, 95% CI: 0·40-0·98).

CONCLUSIONS

More adherence to LCD might be related to lower chance of Mets and some of its components such as low HDL-cholesterol and abdominal obesity specially in men. Further studies are required to confirm the findings.

T. Clark C, Shab-Bidar S. 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.

The relation between dietary phytochemical index and metabolic syndrome and its components in a large sample of Iranian adults: a population-based study

Background

Despite the protective effects of foods being rich in phytochemicals against chronic diseases, this issue is still poorly understood. The aim of this study was to investigate the association between Dietary Phytochemical Index (DPI) and metabolic syndrome (MetS) and its components.

Methods

This cross-sectional study focused on adults aged between 20 and 70years. The dietary intake was assessed using a validated and reliable food frequency questionnaire. DPI was calculated based on dietary energy, derived from phytochemical-rich food sources (kcal) per total daily energy intake (kcal). The odds ratio of MetS and its components were assessed across DPI quartiles by logistic regression models.

Results

After adjustment for all potential confounders, the risk of MetS (OR: 0.63, 95% CI = 0.41–0.96) and elevated blood pressure (OR: 0.62, 95% CI = 0.40–0.96) in the second category of DPI decreased significantly as compared to that in the first category. Subjects in the second and fourth quartiles of DPI with adjusting for age, sex and total energy intake revealed 30 and 25% lower risk of abdominal obesity, respectively. After full adjustment for confounders, the analysis stratified by sex showed women in the highest quartile of DPI had 59% lower risk of MetS (OR: 0.41, 95% CI = 0.22–0.76) as compared to those in the lowest quartile of DPI.

Conclusions

Greater adherence to phytochemical-rich diet could reduce odds of MetS and some components, especially in women. Further studies with intervention approaches are recommended.

Low-carbohydrate diet and maternal glucose metabolism in Chinese pregnant women

Few studies have suggested that long-term adherence to low-carbohydrate diets (LCD) may affect maternal glucose metabolism in Western countries. We aimed to investigate the association between LCD during pregnancy and glucose metabolism in a Chinese population. A total of 1018 women in mid-pregnancy were recruited in 2017-2018. Participants underwent a 75 g oral glucose tolerance test (OGTT). Daily dietary intakes over the past month were accessed using a validated FFQ. The overall, animal and vegetable LCD scores which represent adherence to different low-carbohydrate dietary patterns were calculated. Mixed linear regression and generalised linear mixed regression were conducted to evaluate the associations between LCD scores and maternal glucose metabolism. Of the 1018 subjects, 194 (19·1 %) were diagnosed with gestational diabetes mellitus (GDM). The overall LCD score (β: 0·024, se 0·008, PFDR = 0·02) and animal LCD score (β: 0·023, se 0·008, PFDR = 0·02) were positively associated with OGTT 1-h glucose. No significant associations were found between the three different LCD scores with fasting plasma glucose, OGTT 2-h glucose, or insulin resistance, respectively. Compared with the lowest quartile, the crude OR of GDM for the highest quartile were 1·84 (95 % CI 1·14, 2·95) for overall LCD score (Pfor trend = 0·02) and 1·56 (95 % CI 1·00, 2·45) for animal LCD score (Pfor trend = 0·02). However, these associations became non-significant after adjustment for covariates. In conclusion, a low-carbohydrate dietary pattern with high animal protein and fat is associated with higher postprandial 1-h glucose levels in Chinese pregnant women.

Diet Quality, Physical Activity, and Weight Changes and Their Association With 6-Year Risk of Metabolic Syndrome in Mexican Adults

Background. Among lifestyle factors, obesity has been postulated as the most important risk factor for metabolic syndrome (MS). Lifestyle factors such as physical activity (PA), diet quality, and weight management are so closely related, it is not clear if the role of lifestyle factors is exclusively through its effect on weight, or if they contribute independently. Objective. To examine the effect of lifestyle factors such as diet quality, weight change, and leisure time PA on MS occurrence in lean and overweight/obese (OW/OB) adults over a 6-year period. Methods. This was a longitudinal analysis of data from adults participating in the Health Workers Cohort Study. Results. A total of 1046 participants were included; 37.2% of the OW/OB group and 16.2% of the lean participants developed MS. Becoming overweight had a hazard ratio (HR) of 3.06 for developing MS compared with remaining lean (95% CI = 1.98, 4.74). Going from OW/OB to lean was associated with lower risk of MS (HR = 0.41; 95% CI = 0.22, 0.79). Among OW/OB, becoming active was associated with lower risk (HR = 0.63; 95% CI = 0.42, 0.95) in comparison with an inactive pattern; diet quality was not associated with occurrence of MS. Conclusion. Weight change was the most relevant factor predicting MS over a 6-year period.

The relation between low carbohydrate diet score and psychological disorders among Iranian adults

BACKGROUND

Since evidence regarding to low carbohydrate diet (LCD) and psychiatric disorders is little and controversial, this study aimed to assess relation between LCD score and psychological disorders including depression, anxiety, and stress among a large representative sample of Iranian adult population in Yazd city, Iran.

METHODS

This cross-sectional analysis was conducted on data of 7165 persons who participated in the recruitment phase of Yazd Health Study (YaHS) and Taghzieh Mardom-e-Yazd (TAMIZ) study. Dietary intakes were evaluated by a validated semi-quantitative food frequency questionnaire. LCD score was calculated for each person according to summing up assigned scores to deciles of percentages of energy from macronutrients. Assessment of psychological disorders was also conducted by the validated Iranian version of depression, anxiety and stress scale questionnaire (DASS 21). Eventually, association between adherence to LCD and psychological disorders was evaluated via logistic regression.

RESULTS

After adjusting the confounders, women in the third quartile of LCD score might had 38% lower chance of depression versus those in the first quartile (odds ratio (OR) = 0.62, confidence interval (CI) = 0.42-0.93). However, no significant relationship was observed for other psychological disorders.

CONCLUSIONS

More adherences to LCD might be associated with lower chance of depression only among women. Further studies special prospective studies are required to validate these results.

Development, validation and utilisation of dish-based dietary assessment tools: a scoping review

Objective:

To summarise the existing evidence of development, validation and current status of utilisation of dish-based dietary assessment tools.

Design:

Scoping review.

Setting:

Systematic search using PubMed and Web of Science.

Results:

We identified twelve tools from seventy-four eligible publications. They were developed for Koreans (n 4), Bangladeshis (n 2), Iranians (n 1), Indians/Malays/Chinese (n 1), Japanese (n 3) and Chinese Americans (n 1). Most tools (10/12) were composed of a dish-based FFQ. Although the development process of a dish list varied among the tools, six studies classified mixed dishes based on the similarity of their characteristics such as food ingredients and cooking methods. Tools were validated against self-reported dietary information (n 9) and concentration biomarkers (n 1). In the eight studies assessing the differences between the tool and a reference, the mean (or median) intake of energy significantly differed in five studies, and 26–83 % of nutrients significantly differed in eight studies. Correlation coefficients for energy ranged from 0·15 to 0·87 across the thirteen studies, and the median correlation coefficients for nutrients ranged from 0·12 to 0·77. Dish-based dietary assessment tools were used in fifty-nine studies mainly to assess diet–disease relationships in target populations.

Conclusions:

Dish-based dietary assessment tools have exclusively been developed and used for Asian-origin populations. Further validation studies, particularly biomarker-based studies, are needed to assess the applicability of tools.

Prevalence and Incidence of Metabolic Syndrome in Iran: A Systematic Review and Meta-Analysis

Metabolic syndrome (MetS) is a predictor of several diseases such as cardiovascular diseases, diabetes, dyslipidemia, stroke, osteoarthritis, certain cancers, and death leading to public health concern in most societies. We aimed to estimate the pooled prevalence and incidence of MetS in Iranian population through a meta-analysis study. We included cross-sectional and cohort studies to estimate the overall prevalence and incidence rates of MetS in Iran National databases including MagIran, Science Information Database, IranMedex, and international databases including Medline, Web of Sciences, and Scopus were searched up to October 2017. Finally, 125 studies were included. The total sample size was 472,401 with a mean age of 38 ± 7.8 years. The overall pooled prevalence and incidence rate among the general population of Iran was 0.26 (95% CI: 0.26, 0.29) and 97.96 (95% CI: 75.98, 131.48), respectively. The pooled prevalence of MetS was higher in females and in urban areas. The highest and lowest prevalence of MetS was obtained by the Iranian definition criteria (0.43) and the NHANES III (0.12). The highest and lowest incidence rates of MetS were obtained by IDF (144.07 per 1000) and the JIS (89.73 per 1000). The prevalence of MetS was higher in women and those living in urban areas. Furthermore, the prevalence of MetS increased with increasing age in both genders.

Low-carbohydrate diet and cardiovascular diseases in Iranian population: Tehran Lipid and Glucose Study

BACKGROUND AND AIMS

Studies indicated that the risk of cardiovascular disease (CVD) in association to greater adherence to low-carbohydrate diet (LCD) differs in various populations. In this study, we aimed to assess the association of LCD score with the risk of CVD events in a prospective population-based study.

METHODS AND RESULTS

CVD-free participants (n = 2188) were recruited from the Tehran Lipid and Glucose Study (2006-2008) and followed for a mean of 6.7 years. Using a valid and reliable 168 item semi-quantitative food frequency questionnaire, the LCD score was determined based on the percentage of energy as carbohydrate, protein, and fat, which ranged from 0 to 12. Cox proportional hazard regression models, adjusted for potential confounders, were used to estimate the hazard ratios (HRs) and 95% confidence interval (CI) of CVD across tertiles of LCD score in women and men. Mean ± SD age of participants (44.8% male) was 38.8 ± 13.0 years, and median (25-75, interquartile range) of the LCD score was 6 (4-8) at baseline. During follow-up, 77 (3.5%) new cases of CVD were identified. After adjustment for sex, age, body mass index, physical activity, smoking, energy intake, diabetes, and hypertension, there was no association between the LCD score and risk of CVD outcomes in all participants (HR = 0.93; 95% CI: 0.86-1.02) and women (HR = 1.13; 95% CI: 0.94-1.36); however, the LCD score was associated with an 11% reduced incidence of CVD events in men (HR = 0.89; 95% CI: 0.80-0.98), (P for trend: 0.028).

CONCLUSION

Findings showed that higher adherence to LCD may be associated with a lower risk of CVD outcomes in men but not in women.

Carbohydrate intake and risk of metabolic syndrome: A dose-response meta-analysis of observational studies

BACKGROUND AND AIMS

Epidemiological association studies have reported inconsistent findings on the relationship between carbohydrate intake and risk of metabolic syndrome (MetS). Therefore, we aimed to conduct the first dose-response meta-analysis to investigate this effect.

METHODS AND RESULTS

A systematic search in PubMed and Web of Science databases from their inception to June 01, 2019, together with relevant literature scrutiny, was performed to identify related studies for inclusion into the meta-analysis. We calculated the odds ratios (ORs) with 95% confidence intervals (CIs) using a random effects model. Furthermore, subgroup, sensitivity, heterogeneity, and publication bias analyses were performed. This meta-analysis included 14 cross-sectional and four cohort studies, totaling 284,638 participants and 69,554 MetS cases. The highest versus the lowest carbohydrate intake values were associated with an increased risk of MetS (OR: 1.253, 95% CI: 1.147-1.368), with moderate heterogeneity (I² = 54.5%). Using dose-response analysis, we found a linear association between carbohydrate consumption and MetS risk with a corresponding OR of 1.026 (95% CI, 1.004-1.048) and with significant heterogeneity (I² = 82.0%) at 5% energy intake from carbohydrates. We have found similar results using subgroup analyses for major study characteristics and adjustment for confounders. Sensitivity analysis further enhanced the robustness of the results, and no publication bias was detected.

CONCLUSION

Carbohydrate intake is associated with an increased risk of developing MetS. Therefore, additional large prospective cohort studies are warranted to confirm our findings.

Association of low-carbohydrate diet score with overweight, obesity and cardiovascular disease risk factors: a cross-sectional study in Iranian women

Introduction: This study aimed to determine the association of low-carbohydrate-diet score with overweight, obesity and cardiovascular risk factors among Iranian women. Methods: In healthy Iranian women 20-50 years, demographics, anthropometrics, physical activity, blood pressure, fasting blood glucose, blood lipids, and dietary intake (using a validated food frequency questionnaire) were assessed. Participants were divided into deciles of macronutrient intakes. Women in the lowest decile of carbohydrate intake received a score of 9 and women in the highest decile received a score of 0. For protein and fat intakes, women in the lowest decile received a score of 0 for that macronutrient and those in the highest decile received the score of 9. Macronutrient scores were summed to create the low-carbohydrate diet score and women were grouped into tertiles based on these scores. Continuous and qualitative variables were compared among the low-carbohydrate-diet score by one-way ANOVA and chi-square test, respectively. Logistic regression was used to determine the association of low-carbohydrate-diet score and cardiovascular risk factors. Results: A total of 209 women were included in the study. Socioeconomic status significantly increased from tertile 1 to 3 of the low-carbohydrate diet score (P = 0.02). Total dietary glycemic index (GI) significantly differed among tertiles (tertile 1 GI: 63.1 ±0.50, tertile 2 GI: 61.9 ± 0.5, tertile 3 GI: 59.5 ± 0.5; P < 0.001). The odds ratios for overweight, obesity and cardiovascular risk factors were not significantly different among the tertiles of low-carbohydrate diet score. Conclusion: In Iranian women, diets lower in carbohydrate and higher in protein and fat were not associated with overweight, obesity and cardiovascular risk factors.

Low-carbohydrate diet and the risk of metabolic syndrome in Korean adults

BACKGROUND & AIMS

The association of low-carbohydrate diet with weight loss and the risk of cardiovascular diseases has recently been the focus of increasing research attention. However, studies on low-carbohydrate diet in the Asian population are limited. The present study was aimed to examine the association between low-carbohydrate diet and metabolic syndrome among Korean adults.

METHODS AND RESULTS

A total of 16,349 participants aged 30 years or older who participated in a 24-h dietary recall survey of the fifth and sixth Korea National Health and Nutrition Examination Survey were included in this study. Low-carbohydrate diet was evaluated using the low-carbohydrate-diet score, which was calculated based on the percentage of energy from carbohydrate, protein, and fat by sex. The association between the low-carbohydrate-diet score and metabolic syndrome was analyzed using multiple logistic regression analysis. A low-carbohydrate diet was not associated with metabolic syndrome and its components such as waist circumference, blood pressure, and triglyceride levels. However, women in the highest decile of the animal- or plant-based low-carbohydrate-diet score showed a decreased risk of reduced high-density lipoprotein (HDL)-cholesterol levels, and men in the highest decile of the animal-based low-carbohydrate-diet score showed a decreased risk of reduced HDL-cholesterol levels than those in the lowest decile of the low-carbohydrate-diet score.

CONCLUSION

These findings indicate that, in Korea, a low-carbohydrate diet did not increase the risk of metabolic syndrome among adults who typically consume a high-carbohydrate low-fat diet. However, it may moderately decrease the risk of reduced HDL-cholesterol levels.

Carbohydrate Intake Exhibited a Positive Association with the Risk of Metabolic Syndrome in Both Semi-Quantitative Food Frequency Questionnaires and 24-Hour Recall in Women

We compared the usual nutrient intake in both the semi-quantitative food frequency questionnaire (SQFFQ) and 24-hour recall methods and determined the association between metabolic syndrome (MetS) risk and nutrient intake calculated by both methods in Korea National Health and Nutrition Examination Survey (KNHANES; 2012-2014) data. Adjusted odds ratios for MetS were calculated according to the intake of macronutrients, measured by the 2 methods in 10,286 adults, while controlling for covariates associated with MetS. Fat and carbohydrate intake (energy percent) calculated by 24-hour recall and SQFFQ was significantly different between the MetS and non-MetS groups, particularly in women. The differences in other nutrient intakes determined by both methods were mainly non-significant. The correlation coefficients between the 2 methods were about 0.4 for most nutrients except total vitamin A and iron (Fe). Energy intake according to gender and MetS presence was similar between the 2 methods. Carbohydrate intake exhibited a positive association with the MetS risk, while fat intake showed a negative association in both methods. The association exhibited a gender interaction with carbohydrate and fat intake calculated by 24-hour recall: women exhibited a significant association. However, for the SQFFQ a gender interaction was evident only for carbohydrate intake. In diet quality index of SQFFQ the adequacy of vegetables and total fat intake was higher in the non-MetS than the MetS. In conclusion, the MetS prevalence exhibited a positive association with carbohydrate intake only in women, as assessed by 24-hour recall and SQFFQ. The SQFFQ can be used to assess the association between usual food intake and MetS risk in large population studies.

High carbohydrate diets are positively associated with the risk of metabolic syndrome irrespective to fatty acid composition in women: the KNHANES 2007-2014

We evaluated that carbohydrates and fatty acids intake modifies the prevalence of metabolic syndrome (MetS) and we also determined gender-nutrient interaction in 38,766 adults in KNHANES (2007-2014). Carbohydrate intake was positively associated, and fat intake inversely associated, with the incidence of MetS. The association exhibited a gender interaction with the macronutrient intake; this association was significant in females. Furthermore, saturated fatty acid (SFA), monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA) intakes were inversely associated with MetS risk and only females showed the positive association. Both n-3 and n-6 fatty acids intake showed inverse associations with MetS risk, similar to PUFA intake. Among the MetS components, serum triglyceride levels and blood pressure had significant inverse associations with fatty acid intake irrespective of fatty acid types and exhibited a gender interaction. In conclusions, high carbohydrate intakes (≥74.2 En%) may increase the MetS risk and moderate fat intakes (≥20.7 En%), irrespective of fat types, may decrease it. These associations were significant only in women.