Low-carbohydrate Diet Score Research Articles

Association of the low-carbohydrate dietary pattern with postpartum weight retention in women.

Low-carbohydrate diets (LCD) have been considered a popular dietary strategy for weight loss. However, the association of the low-carbohydrate dietary pattern with postpartum weight retention (PPWR) in women remains unknown. The present study involved 426 women from a prospective mother-infant cohort study. Overall, animal or plant LCD scores, which represent adherence to different low-carbohydrate dietary patterns, were calculated using diet intake information assessed by three consecutive 24 h dietary surveys. PPWR was assessed by the difference of weight at 1 year postpartum minus the pre-pregnancy weight. After adjusting for potential confounding variables, women in higher quartiles of total and animal-based LCD scores had a significantly lower body weight and weight retention at 1 year postpartum (P < 0.05). The multivariable-adjusted ORs of substantial PPWR (≥5 kg), comparing the highest with the lowest quartile, were 0.47 (95% confidence interval 0.23-0.96) for the total LCD score (P = 0.021 for trend) and 0.38 (95% confidence interval 0.19-0.77) for the animal-based LCD score (P = 0.019 for trend), while this association was significantly attenuated by rice, glycemic load, fish, poultry, animal fat and animal protein (P for trend <0.05). A high score for plant-based LCD was not significantly associated with the risk of PPWR (P > 0.05). The findings suggested that a low-carbohydrate dietary pattern, particularly with high protein and fat intake from animal-source foods, is associated with a decreased risk of weight retention at 1 year postpartum. This association was mainly due to low intake of glycemic load and high intake of fish and poultry.

Plant-Based and Animal-Based Low-Carbohydrate Diets and Risk of Hepatocellular Carcinoma Among US Men and Women.

Little is known about the role of low-carbohydrate diets (LCDs) in the development of hepatocellular carcinoma (HCC). We prospectively evaluated the associations between plant-based and animal-based LCDs and risk of HCC in the Nurses' Health Study (NHS) and the Health Professionals Follow-up Study (HPFS). Dietary intake was assessed every 4years using validated food frequency questionnaires. Cox proportional hazards regression models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs). HRs are shown for a 1-standard deviation (SD) increment with variables modeled as continuous. During 3,664,769 person-years of follow-up, there were 156 incident HCC cases. Although there were no associations between overall or animal-based LCD score and risk of HCC, plant-based LCD score was inversely associated with HCC risk (HR, 0.83; 95% CI, 0.70-0.98; Ptrend =0.03). Carbohydrate intake, especially from refined grains (HR, 1.18; 95% CI, 1.00-1.39; Ptrend =0.04), was positively, while plant fat (HR, 0.78; 95% CI, 0.65-0.95; Ptrend =0.01) was inversely associated with HCC risk. Substituting 5% of energy from plant fat and protein for carbohydrate (HR, 0.74; 95% CI, 0.58-0.93; Ptrend =0.01) or refined grains (HR, 0.70; 95% CI, 0.55-0.90; Ptrend =0.006) was associated with lower HCC risk. In conclusion, a plant-based LCD and dietary restriction of carbohydrate from refined grains were associated with a lower risk of HCC. Substituting plant fat and protein for carbohydrate, particularly refined grains, may decrease HCC incidence. Our findings support a potential benefit in emphasizing plant sources of fat and protein in the diet for HCC primary prevention; additional studies that carefully consider hepatitis B and C virus infections and chronic liver diseases are needed to confirm our findings.

Low-Carbohydrate Diet Score and Coronary Artery Calcium Progression: Results From the CARDIA Study.

To investigate whether low-carbohydrate diets (LCDs) were associated with coronary artery calcium (CAC) progression. Approach and Results: We included the participants who completed computed tomography assessment of baseline CAC in 2000 to 2001 (year 15) and follow-up (year 20 or 25) and food frequency questionnaire (years 0, 7, and 20) in the CARDIA study (Coronary Artery Risk Development in Young Adults). CAC progression was defined as CAC >0 at follow-up among participants with baseline CAC of 0 and an annualized change of 10 or percent change of ≥10% for those with 0<baseline CAC<100 or baseline CAC≥100, respectively. Among 2226 included participants (age, 40.4±3.5 years; 45.4% men), the carbohydrate intake accounted for 47.8±6.5% of total energy, and 204 (9.2%) had CAC at baseline (year 15). Over a mean follow-up of 8.3 years, 591 (26.5%) participants had CAC progression. After adjustment for traditional cardiovascular risk factors and other dietary factors, carbohydrate intake as a percentage of total energy was inversely associated with the risk of CAC progression (hazard ratio, 0.731 [95% CI, 0.552-0.968]; P=0.029). Furthermore, the animal-based but not plant-based LCD score was significantly associated with a higher risk of CAC progression (animal-based LCD score: hazard ratio, 1.456 [95% CI, 1.015-2.089]; P=0.041; plant-based LCD score: hazard ratio, 1.016 [95% CI, 0.821-1.257]; P=0.884; both comparing extreme groups). LCDs starting at a young age are associated with an increased risk of subsequent CAC progression, particularly when animal protein or fat are chosen to replace carbohydrates. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT00005130.

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.

Animal based low carbohydrate diet is associated with increased risk of type 2 diabetes in Tehranian adults

BackgroundTo investigate the association of low carbohydrate diet (LCD) score with the risk of type 2 diabetes among adults.MethodsThis cohort study was conducted on 4356 healthy participants aged ≥ 19 years old, who were followed-up for a mean duration of 3 years within the framework of the Tehran Lipid and Glucose Study. LCD score was calculated using a food frequency questionnaire according to intake of carbohydrate, protein, and fat at baseline. Diabetes was defined according to the criteria of the American Diabetes Association. Multivariable logistic regression models, adjusted for potential confounders, were used to estimate risk of diabetes across quartiles of LCD score.ResultsMean ± SD age of the study participants (44.4% men) was 40.5 ± 13.0 years. The median (25–75 interquartile range) of LCD score was 17.0 (12.0–21.0) and after a 3 year follow-up period, 123 (2.8%) incident cases of diabetes were ascertained. After adjustment for confounding variables, including age, sex, smoking status, physical activity, total calorie intake, saturated fatty acid, waist circumference, educational level, and family history of diabetes, the multivariable-adjusted ORs (95% CIs) of type 2 diabetes, comparing the highest with the lowest quartiles, were 2.16 (1.16–4.04) for total LCD score (P-value = 0.015), 1.81 (1.06–3.11) for animal-based LCD score (P-value = 0.029), and 1.47 (0.85–2.52) for plant-based LCD score (P-value = 0.160).ConclusionOur findings suggest that a higher adherence to LCD, mostly with higher intakes of protein and fat from animal-source foods, can increase the incidence of diabetes; however, a plant-based low-carbohydrate dietary pattern is not significantly associated with risk of type 2 diabetes.

Low carbohydrate diet and all cause and cause-specific mortality

Evidence is limited regarding the association between low-carbohydrate diet (LCD) score and mortality among Asians, a population that consumes a large amount of carbohydrates. The present study examined the association between low-carbohydrate diet (LCD) score (based on percentage of energy as carbohydrate, fat, and protein) and the risk of total and cause-specific mortality among Asians. This study was a prospective cohort study in Japan with follow-up for a median of 16.9 years involving 43008 men and 50646 women aged 45-75 years. Association of LCD score, LCD score based on animal sources of protein and fat, and LCD score based on plant sources of protein and fat with risk of mortality was assessed using Cox proportional hazards model. A U-shaped association was observed between LCD score and total mortality: the multivariable-adjusted hazard ratios (HRs) (95% CI) of total mortality for lowest through highest scores were 1.00, 0.95 (0.91, 1.01), 0.93 (0.88, 0.98), 0.93 (0.88, 0.98), and 1.01 (0.95, 1.07) (P-non-linearity <0.01). A similar association was found for mortality from cardiovascular disease (CVD) and heart disease. LCD score based on carbohydrate, animal protein, and animal fat also showed a U-shaped association for total mortality (P-non-linearity <0.01). In contrast, LCD score based on carbohydrate, plant protein, and plant fat was linearly associated with lower total (HR, 0.89; 95% CI: 0.83, 0.94 for highest versus lowest quintile), CVD [0.82 (0.73, 0.92)], heart disease [0.83 (0.71, 0.98)], and cerebrovascular disease [0.75 (0.62, 0.91) mortality. Both LCD with high animal protein and fat and high-carbohydrate diet with low animal protein and fat were associated with higher risk of mortality. Meanwhile, LCD high in plant-based sources of protein and fat was associated with a lower risk of total and CVD mortality.

Adherence to low-carbohydrate diet in relation to gastric cancer: findings from a case-control study in Iran.

This study examined the association between adherence to low carbohydrate diet (LCD) and risk of gastric cancer (GC). This hospital-based case-control study was conducted in Iran Cancer Institute, Tehran, Iran between 2010 and 2012. Totally, 178 patients with GC and 276 apparently healthy controls participated in this study. Cases were histo-pathologically confirmed GC patients aged ≥40 years diagnosed with GC in the last year. Dietary intakes were assessed using a validated 146-item Diet History Questionnaire. We computed the LCD score trough the protocol explained by Halton. Patients with GC were older (60.8 vs. 53.2 years, P < 0.001) and more likely to be male (74.2 vs. 63.8%, P = 0.02), married (97.8 vs. 86.6%, P < 0.001) and illiterate (62.4% vs. 26.1%, P < 0.001) than controls. Before adjusting for covariates, adherence to LCD-diet was not associated with risk of GC [odds ratio (OR) 1.31; 95% confidence interval (CI) 0.82-2.09 for highest vs. lowest tertile; Ptrend < 0.26]. Adjustments for several potential confounders including H-pylori infection and BMI, participants in the highest tertile of LCD score were 7% more likely to have GC than those in the lowest tertile; however, it was not statistically significant (OR 1.07; 95% CI 0.59-1.95 for highest vs. lowest tertile; Ptrend < 0.79). No significant association was also seen between adherence to animal- or vegetable-based LCD diet and risk of GC. In conclusion, we failed to find any evidence on the association between consumption of LCD and odds of GC. Further studies, in particular of prospective design, are required to confirm these findings.

Low carbohydrate diet score and odds of neuromyelitis optica spectrum disorder: A case-control study.

Introduction: Neuromyelitis optica spectrum disorder (NMOSD) is a demyelinating inflammatory disease of The Central nervous system. We aimed to investigate the association between low carbohydrate diet (LCD) and NMOSD odds. Method: Seventy NMOSD patients with definite diagnosis and 164 hospital-based controls were enrolled in this case-control study. Dietary data was obtained using a validated 168-item food frequency questionnaire. To determine the LCD score, participants were stratified into 11 groups according to carbohydrate, protein, fat, animal fat, animal protein, vegetable fat and vegetable protein intakes. Higher intake of protein and fat, and lower intake of carbohydrate received a higher score between 0-10. Macronutrients scores were summed together and LCD scores calculated. The association between LCD scores and likelihood of being assigned to NMOSD group was investigated using multiple regression models. Results: Total LCD scores increased from the median of 21.00 in the first decile to 53.00 in the tenth decile of LCD score. After adjustment for confounding factors including age, gender, BMI, energy intake, cigarette smoking and alcohol consumption, an inverse association was detected between LCD scores and odds of NMOSD. The odds of suffering from NMOSD declined significantly about 78% (OR: 0.22; 95% CI: 0.05-0.87) and 76% (OR: 0.24; 95% CI: 0.06-0.93) in the fifth and sixth deciles of LCD score compared to the first decile. Conclusion: From the obtained results it can be speculated that higher carbohydrate and lower protein and fat intakes may be associate with the increased odds of NMOSD. However, further studies are needed to confirm these results.

Association between Three Low-Carbohydrate Diet Scores and Lipid Metabolism among Chinese Adults.

This study investigated the blood lipid levels of 5921 Chinese adults aged >18 years using data from the China Health and Nutrition Survey 2009. Diet information was collected through 3 day, 24 h recalls by trained professionals. The low-carbohydrate diet (LCD) score was determined according to the percentage of energy obtained from carbohydrate, protein, and fat consumption. Dyslipidemia was defined when one or more of the following abnormal lipid levels were observed: high cholesterol levels, high triglyceride levels, and low high-density lipoprotein cholesterol levels. Multivariate adjusted odds ratios (ORs) and their 95% confidence intervals (95% CIs) were calculated using logistic regression models. After adjusting the confounding variables, in males, the OR of hypercholesterolemia was 1.87 (95% CI, 1.23–2.85; p for trend = 0.0017) and the OR of hypertriglyceridemia was 1.47 (95% CI, 1.04–2.06; p for trend = 0.0336), on comparing the highest and lowest quartiles of the LCD score. The animal-based LCD score showed a similar trend. The OR of hypercholesterolemia was 2.15 (95% CI, 1.41–3.29; p for trend = 0.0006) and the OR of hypertriglyceridemia was 1.51 (95% CI, 1.09–2.10; p for trend = 0.0156). However, there was no significant difference between plant-based LCD scores and dyslipidemia. In females, lipid profiles did not differ much among the quartiles of LCD scores—only the animal-based LCD score was statistically significant with hypercholesterolemia. The OR of hypercholesterolemia was 1.64 (95% CI, 1.06–2.55), on comparing the highest and lowest quartiles of the LCD score. In conclusion, a higher LCD score, indicating lower carbohydrate intake and higher fat intake, especially animal-based fat, was significantly associated with higher odds of hypercholesterolemia and hypertriglyceridemia in Chinese males. Future studies investigating the potential mechanisms by which macronutrient types and sex hormones affect lipid metabolism are required.

The Relationship between Low Carbohydrate Diet Score and Mental Health in Overweight and Obese Women

The Relationship between Low Carbohydrate Diet Score and Mental Health in Overweight and Obese Women

Association of low-carbohydrate diet score with perceived stress score: A cross-sectional study in Iranian nurses

Association of low-carbohydrate diet score with perceived stress score: A cross-sectional study in Iranian nurses

Association between a low-carbohydrate diet and sleep status, depression, anxiety, and stress score.

Dietary intakes, especially carbohydrates, play an important role in blood glucose control in patients with diabetes. It is suggested that carbohydrate amounts may be effective in diabetes complications. This study aimed to reveal the association of low-carbohydrate diet (LCD) and sleep and mental status among patients with diabetes. This cross-sectional study was conducted among 265 women with type 2 diabetes. Anthropometric measures, as well as biochemical tests, were recorded. Dietary intakes were recorded using a validated food-frequency-questionnaire to calculate LCD score. To assess mental disorders and sleep quality, the Depression, Anxiety and Stress Scale and the Pittsburgh Sleep Quality Index were used respectively. Patients in the highest LCD quartile were the ones with the lowest carbohydrate consumption. There was no significant association between cardiovascular risk factors and LCD score even after controlling confounder variables (P > 0.05). Subjects in the highest quartile of LCD score compared with those within the lowest quartile had a 69% lower risk of poor sleep after adjusting confounders. The odds of depressive symptoms were negatively related to the highest quartile of LCD score in the crude model and even after full-adjusted model (odds ratio: 0.42; 95% confidence interval: 0.17-1.01). Participants in the highest quartile of LCD score compared with those in the lowest quartile had a 73% lower risk of anxiety. It seems that patients who consumed lower carbohydrate have better sleep status and are less involved with mental disorders. However, regarding the nature of the present study, well-designed cohort studies are suggested to be conducted in the future. © 2020 Society of Chemical Industry.

Dietary characteristics associated with plasma concentrations of per- and polyfluoroalkyl substances among adults with pre-diabetes: Cross-sectional results from the Diabetes Prevention Program Trial

Diet is assumed to be the main source of exposure to per- and polyfluoroalkyl substances (PFAS) in non-occupationally exposed populations, but studies on the diet-PFAS relationship in the United States are scarce. We extracted multiple dietary variables, including daily intakes of food group, diet scores, and dietary patterns, from self-reported dietary data collected at baseline (1996–1999) from adults with pre-diabetes enrolled in the Diabetes Prevention Program, and used linear regression models to evaluate relationships of each dietary variable with plasma concentrations of six PFAS (perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorohexane sulfonic acid (PFHxS), 2-(N-ethyl-perfluorooctane sulfonamido) acetic acid (EtFOSAA), 2-(N-methyl-perfluorooctane sulfonamido) acetic acid (MeFOSAA), perfluorononanoic acid (PFNA) adjusting for covariates. Participants (N = 941, 65% female, 58% Caucasian, 68% married, 75% with higher education, 95% nonsmoker) had similar PFAS concentrations compared to the general U.S. population during 1999–2000. Using a single food group approach, fried fish, other fish/shellfish, meat and poultry had positive associations with most PFAS plasma concentrations. The strongest effect estimate detected was between fried fish and PFNA [13.6% (95% CI: 7.7, 19.9) increase in median concentration per SD increase]. Low-carbohydrate and high protein diet score had positive association with plasma PFHxS. Some food groups, mostly vegetables and fruits, and the Dietary Approaches to Stop Hypertension diet score had inverse associations with PFOS and MeFOSAA. A vegetable diet pattern was associated with lower plasma concentrations of MeFOSAA, while high-fat meat and low-fiber and high-fat grains diet patterns were associated with higher plasma concentrations of PFOS, PFHxS, MeFOSAA and PFNA. We summarized four major dietary characteristics associated with variations in PFAS plasma concentrations in this population. Specifically, consuming more meat/fish/shellfish (especially fried fish, and excluding Omega3-rich fish), low-fiber and high-fat bread/cereal/rice/pasta, and coffee/tea was associated with higher plasma concentrations while dietary patterns of vegetables, fruits and Omega-3 rich fish were associated with lower plasma concentrations of some PFAS.

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

Background and aimsStudies 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 resultsCVD-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). ConclusionFindings showed that higher adherence to LCD may be associated with a lower risk of CVD outcomes in men but not in women.

Adherence to the low carbohydrate diet and the risk of breast Cancer in Iran

BackgroundPrevious studies on the link between macronutrients and breast cancer have mostly focused on individual macronutrients rather than their combination. This study investigates the association between adherence to a low carbohydrate diet and odds of breast cancer among women.MethodsThis hospital-based case-control study was carried out on 412 women with pathologically confirmed breast cancer within the past year and 456 apparently healthy controls that were matched in terms of age and residential place. Dietary data was collected using a 168-item validated FFQ. Participants were classified in terms of quintiles of percentages of energy intake from carbohydrates, proteins, and fats. Then, individuals in the highest quintile of fat and protein intake were given a score of 5 and those in the lowest quintile of these macronutrients were given a score of 1. Participants in the other quintiles of these macronutrients were given the corresponding score. In terms of carbohydrate intake, those in the highest quintile received a score of 1 and those in the lowest quintile received 5. The scores were then summed up to calculate the total low carbohydrate diet (LCD) score, which varied from 3 to 15. A higher score meant greater adherence to a low carbohydrate diet.ResultsThe mean age of study participants was 45.2 y and mean BMI was 28.4 kg/m2. Mean LCD score of participants was 8.9 ± 2.5 (8.9 ± 2.6 in cases and 9.0 ± 2.5 in controls). Although no significant association was observed between adherence to the LCD score and odds of breast cancer in the study population, a trend toward significant positive association was seen between consumption of LCD and odds of breast cancer in postmenopausal women; after controlling for several potential confounders, individuals in the third quartile of LCD score were 1.94 times more likely to have breast cancer than those in the lowest quartile (95% CI: 1.00, 3.76). This association strengthened after controlling for dietary variables (2.50; 1.18–5.32). Even after further adjustment for BMI, this association remained significant (2.64, 1.23–5.67). No significant relationship was observed in premenopausal women, either before or after controlling for confounders.ConclusionAdherence to LCD may be associated with increased odds of breast cancer in postmenopausal women. Prospective cohort studies are needed to confirm these findings.

Adherence to low carbohydrate diet and prevalence of psychological disorders in adults

BackgroundAlthough individual macronutrients were studied in relation to mental health, no information exist about the association between adherence to low carbohydrate diet and psychological disorders. This study was conducted to investigate the association between adherence to a low carbohydrate diet and prevalence of psychological disorders among Iranian adults.MethodsIn this cross-sectional study on 3362 adult men and women, dietary intakes were examined by the use of a validated semi-quantitative food frequency questionnaire. Low carbohydrate diet (LCD) score was computed for each participant based on deciles of percentages of energy from macronutrients. Then the scores of carbohydrate, protein and fat intake for each participant were summed up to achieve the overall LCD score, which ranged from 3 (highest carbohydrate intake and lowest fat and protein intakes) to 30 (lowest carbohydrate intake and highest fat and protein intakes). Anxiety, depression, and psychological distress were assessed by validated Iranian versions of the Hospital Anxiety and Depression Scale and General Health Questionnaire-12.ResultsPrevalence of depression, anxiety and psychological distress in the whole population were 28.0, 13.3 and 22.6%, respectively. No significant differences were observed in the distribution of depression, anxiety and psychological distress across different quartiles of LCD score. After controlling for potential confounders, no significant association was seen between LCD score and prevalence of depression (OR for the highest vs. the lowest quartile of LCD score: (1.15; 95% CI: 0.93, 1.39). Consumption of LCD was not also associated with increased risk of anxiety (0.82; 95% CI: 0.59, 1.14) and psychological distress (0.92; 95% CI: 0.72, 1.16). These associations did not alter when the analyses were done stratified by gender or BMI status.ConclusionAdherence to the low carbohydrate diet, which contains high amount of fat and proteins but low amounts of carbohydrates, was not associated with increased odds of psychological disorders including depression, anxiety and psychological distress. Given the cross-sectional nature of the study which cannot reflect causal relationships, longitudinal studies, focusing on types of macronutrients, are required to clarify this association.

Carbohydrate restriction in midlife is associated with higher risk of type 2 diabetes among Australian women: A cohort study

Background and aimsLow-carbohydrate diets (LCDs) are increasingly popular but may be nutritionally inadequate. We aimed to examine if carbohydrate restriction in midlife is associated with risk of developing type 2 diabetes (T2DM), and if this association differs by previous gestational diabetes (GDM) diagnosis. Methods and resultsDietary intake was assessed for 9689 women from the Australian Longitudinal Study on Women's Health in 2001 (aged 50–55) and 2013 (aged 62–67) via validated food frequency questionnaires. Average long-term carbohydrate restriction was assessed using a low-carbohydrate diet score (highest quartile (Q4) indicating lowest proportion of energy from carbohydrates). Incidence of T2DM between 2001 and 2016 was self-reported at 3-yearly surveys. Log-binomial regression was used to estimate relative risks (RR) and 95% CIs. During 15 years of follow-up, 959 women (9.9%) developed T2DM. Carbohydrate restriction was associated with T2DM after adjustment for sociodemographic factors, history of GDM diagnosis and physical activity (Q4 vs Q1: RR 1.27 [95% CI 1.10, 1.48]), and this was attenuated when additionally adjusted for BMI (1.10 [0.95, 1.27]). Carbohydrate restriction was associated with lower consumption of fruit, cereals and high-fibre bread, and lower intakes of these food groups were associated with higher T2DM risk. Associations did not differ by history of GDM (P for interaction >0.15). ConclusionCarbohydrate restriction was associated with higher T2DM incidence in middle-aged women, regardless of GDM history. Health professionals should advise women to avoid LCDs that are low in fruit and grains, and to consume a diet in line with current dietary recommendations.

Associations between Low-Carbohydrate Diets from Animal and Plant Sources and Dyslipidemia among Korean Adults

BackgroundThe traditional Korean diet is relatively high in carbohydrate and low in fat and protein compared with diets of non-Asian populations. In recent decades, the rapid economic growth in Korea has led to lifestyle and dietary changes, with an increase in the prevalence of dyslipidemia, a risk factor for chronic diseases. ObjectiveTo examine the association between a low carbohydrate diet (LCD) score and dyslipidemia in Korean adults. DesignThe Korea National Health and Nutrition Examination Survey is an ongoing nationally representative population-based cross-sectional survey that is conducted annually. Participants/settingA total of 12,199 Korea National Health and Nutrition Examination Survey participants aged ≥20 years from 2010 to 2016 were included in this study. Main outcome measuresIndividual components of dyslipidemia, such as hypercholesterolemia, hypertriglyceridemia, and low high-density lipoprotein cholesterol levels, were defined based on fasting blood test results. Statistical analysesParticipants were classified by sex into quintiles of LCD scores calculated using 1-day 24-hour dietary recall data. A multivariable logistic regression model was used to examine the association between LCD score and each dyslipidemia component after adjusting for potential confounders. ResultsA higher LCD score was significantly associated with higher odds of hypercholesterolemia (odds ratio 1.36, 95% CI, 1.05 to 1.78; P for trend=0.031) and lower odds of low high-density lipoprotein cholesterol levels (odds ratio 0.72, 95% CI 0.55 to 0.94; P for trend=0.002) in women. However, in men, higher LCD scores were significantly associated with lower odds of hypertriglyceridemia (odds ratio 0.70, 95% CI 0.52 to 0.95; P for trend=0.012). More specifically, animal-based LCD scores were negatively associated with the odds of hypertriglyceridemia (odds ratio 0.65, 95% CI 0.48 to 0.87; P for trend=0.010) in men. ConclusionsThese results suggest that the complicated and integrated effects of macronutrient composition on individual lipid components should be considered for preventing dyslipidemia in Korean adults.

P15 Low-Carbohydrate Diet was Not Associated with Diabetic Retinopathy: Results From US Representative Adults with Diabetes Mellitus

Background As there are no specific dietary recommendations for people with diabetes mellitus (DM), they can choose eating patterns, which they deem helpful in managing blood glucose levels. Objective To describe the dietary intakes of people with DM and to examine the association between the low- carbohydrate-diet (LCD) pattern and diabetic retinopathy (DR). Study Design, Settings, Participants Cross-sectional analysis of the 2005 to 2016 National Health and Nutrition Examination Survey (NHANES). Secondary database analysis. Population-based sample of 3,313 participants with DM in the NHANES 2005-2016. Measurable Outcome/Analysis The presence of DR was self-reported, and LCD score was calculated based on the proportions of energy from three macronutrients (range 0-30; a higher LCD score indicates a lower intake of carbohydrate). The relative risk of DR comparing highest and lowest quintiles of the LCD score was evaluated in multiple logistic regression analysis. Results The average diet of adults with DM consisted of 48 ± 11% of carbohydrate and 35 ± 10% of fat with a mean LCD score of 15.0 ± 7.4. 20.6% of participants reported having DR, and it was associated with male gender, non-Hispanic Blacks and other race/ethnicity, smoking, overweight/obesity, lower education, lower income, HgA1c, and time since diagnosis. After multivariable adjustment, the odds ratio (OR) of having DR comparing highest (carbohydrate 33.9%) and lowest (carbohydrate 62.9%) quintile of the LCD score was 1.01 (95% confidence interval [CI], 0.59 to 1.72; Ptrend = 0.4702). There was no difference in HgA1c levels between the comparison groups (7.51 ± 1.94 vs. 7.40 ± 1.85; P = .131). Post-hoc analysis showed higher diet quality was associated with decreased risk of DR among males (OR comparing highest and lowest quintile, 0.44; 95% CI, 0.20 to 0.98; Ptrend = 0.074). Conclusion Diets lower in carbohydrate are not associated with decreased risk of DR in adults with DM. Targeting diet quality may have greater impacts on improving diabetic prognosis. Funding University of Central Florida.

Lower carbohydrate diets and all-cause and cause-specific mortality: a population-based cohort study and pooling of prospective studies.

Little is known about the long-term association between low-carbohydrate diets (LCDs) and mortality. We evaluated the link between LCD and overall or cause-specific mortality using both individual data and pooled prospective studies. Data on diets from the National Health and Nutrition Examination Survey (NHANES; 1999-2010) were analysed. Multivariable Cox proportional hazards were applied to determine the hazard ratios and 95% confidence intervals (CIs) for mortality for each quartile of the LCD score, with the lowest quartile (Q1-with the highest carbohydrates intake) used as reference. We used adjusted Cox regression to determine the risk ratio (RR) and 95% CI, as well as random effects models and generic inverse variance methods to synthesize quantitative and pooled data, followed by a leave-one-out method for sensitivity analysis. Overall, 24825 participants from NHANES study were included (mean follow-up 6.4 years). After adjustment, participants with the lowest carbohydrates intake (quartile 4 of LCD) had the highest risk of overall (32%), cardiovascular disease (CVD) (50%), cerebrovascular (51%), and cancer (36%) mortality. In the same model, the association between LCD and overall mortality was stronger in the non-obese (48%) than in the obese (19%) participants. Findings on pooled data of nine prospective cohort studies with 462934 participants (mean follow-up 16.1 years) indicated a positive association between LCD and overall (RR 1.22, 95% CI 1.06-1.39, P < 0.001, I2 = 8.6), CVD (RR 1.13, 95% CI 1.02-1.24, P < 0.001, I2 = 11.2), and cancer mortality (RR 1.08, 95% CI 1.01-1.14, P = 0.02, I2 = 10.3). These findings were robust in sensitivity analyses. Our study suggests a potentially unfavourable association of LCD with overall and cause-specific mortality, based on both new analyses of an established cohort and by pooling previous cohort studies. Given the nature of the study, causality cannot be proven; we cannot rule out residual bias. Nevertheless, further studies are needed to extend these important findings, which if confirmed, may suggest a need to rethink recommendations for LCD in clinical practice.