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Aims/Introduction: Efficacy of long‐term low‐carbohydrate diets (LCD) to improve glycemic management for type 2 diabetes remains controversial. Thus, we investigated the association between long‐term LCD and glycemic control in individuals with type 2 diabetes. Materials and Methods: We searched PubMed, Embase and the Cochrane Database for articles published up to June 2023, and included randomized controlled trials conducted on LCD interventions for >12 months in adults with type 2 diabetes. Primary outcome was the difference in glycated hemoglobin between long‐term LCD and control groups. Additionally, we evaluated the differences in changes in systolic and diastolic blood pressure, low‐density lipoprotein cholesterol, high‐density lipoprotein cholesterol, triglyceride, and weight between long‐term LCD and control groups. Results: Six studies were identified and met the inclusion criteria. This study did not show significant differences in changes in glycated hemoglobin between long‐term LCD and control diets (standardized mean difference −0.11, 95% confidence interval −0.33 to 0.11, P = 0.32). As with glycemic control, there were no significant differences in the changes in weight loss, blood pressure, and low‐density lipoprotein cholesterol between long‐term LCD and control diets. However, long‐term LCD were associated with greater elevation in high‐density lipoprotein cholesterol (standardized mean difference 0.22, 95% confidence interval 0.04–0.41; P = 0.02) and decrease in triglyceride (standardized mean difference −0.19; 95% confidence interval −0.37 to 0.02; P = 0.03) than that in control diets. Conclusions: Our findings suggest efficacy of long‐term LCD in treating dyslipidemia in individuals with type 2 diabetes, but do not recommend long‐term LCD for glycemic control in the individuals. [ABSTRACT FROM AUTHOR]

Aims: Co‐management of weight and glycaemia is critical yet challenging in type 1 diabetes (T1D). We evaluated the effect of a hypocaloric low carbohydrate, hypocaloric moderate low fat, and Mediterranean diet without calorie restriction on weight and glycaemia in young adults with T1D and overweight or obesity. Materials and Methods: We implemented a 9‐month Sequential, Multiple Assignment, Randomized Trial pilot among adults aged 19‐30 years with T1D for ≥1 year and body mass index 27‐39.9 kg/m2. Re‐randomization occurred at 3 and 6 months if the assigned diet was not acceptable or not effective. We report results from the initial 3‐month diet period and re‐randomization statistics before shutdowns due to COVID‐19 for primary [weight, haemoglobin A1c (HbA1c), percentage of time below range <70 mg/dl] and secondary outcomes [body fat percentage, percentage of time in range (70‐180 mg/dl), and percentage of time below range <54 mg/dl]. Models adjusted for design, demographic and clinical covariates tested changes in outcomes and diet differences. Results: Adjusted weight and HbA1c (n = 38) changed by −2.7 kg (95% CI −3.8, −1.5, P <.0001) and −0.91 percentage points (95% CI −1.5, −0.30, P =.005), respectively, while adjusted body fat percentage remained stable, on average (P =.21). Hypoglycaemia indices remained unchanged following adjustment (n = 28, P >.05). Variability in all outcomes, including weight change, was considerable (57.9% were re‐randomized primarily due to loss of <2% body weight). No outcomes varied by diet. Conclusions: Three months of a diet, irrespective of macronutrient distribution or caloric restriction, resulted in weight loss while improving or maintaining HbA1c levels without increasing hypoglycaemia in adults with T1D. [ABSTRACT FROM AUTHOR]

Obesity is associated with numerous co‐morbidities and diet, is one of the modifiable risk factors for prevention against these obesity‐related metabolic disorders. In the current study, we aimed to evaluate the association between adherence to low carbohydrate diet (LCD) score and serum lipids, glycemic markers, blood pressure, and anthropometric parameters among obese individuals. The current cross‐sectional study is a combination of two projects with total participants of 359 obese individuals (body mass index [BMI] ≥ 30 kg/m2) aged 20–50 years were included. Dietary intake was assessed by a validated semi‐quantitative food frequency questionnaire (FFQ) of 132 food items. Low carbohydrate diet score was estimated by deciles of dietary intakes. Metabolic syndrome (MetS) was defined based on the guidelines of the National Cholesterol Education Program Adult Treatment Panel III (NCEP‐ATP III). Enzymatic methods were used to assess serum lipids, glucose, and insulin concentrations. Blood pressure was measured by sphygmomanometer and body composition with bioelectrical impedance analysis (BIA). Higher adherence to LCD score was associated with significantly lower DBP and triglyceride (TG) concentrations and increased high density lipoprotein (HDL)‐C levels after adjustment for the confounders (p < 0.05). A non‐significant reduction in systolic blood pressure (SBP) and total cholesterol (TC) values were also observed. Also, high adherence to LCD score was associated with reduced prevalence of metabolic syndrome (p < 0.05). Higher BMI, fat mass, and lower fat‐free mass were also accompanied with higher adherence to LCD score. According to our study, low carbohydrate diet score was associated with more favorable cardio‐metabolic risk factors independent of some confounders like age, BMI, sex, and physical activity level. Further studies in different communities will help for generalization of our findings. [ABSTRACT FROM AUTHOR]

Poor sleep quality can lead to increased obesity. Low carbohydrate diet (LCD) is considered as an approach for sleep quality and obesity improvement. The aim of this investigation is to evaluate the relationship between LCD and sleep quality with the mediatory effect of inflammatory markers including transforming growth factor‐β (TGF‐β), high‐sensitivity C‐reactive protein (hs‐CRP), total antioxidant capacity: In our cross‐sectional study, 304 obese women aged from 19 to 50 years were enrolled. Body mass index (BMI) in these women ranged from 25.2 to 48.3 kg/m2. LCD score was assessed by a 147‐ item semi‐quantitative food frequency questionnaire (FFQ). The Pittsburgh Sleep Quality Index (PSQI) was used to assess the sleep quality. FFQ and PSQI questionnaires are completed simultaneously by the participants. Biochemical indicators (inflammatory markers) were measured and anthropometric components were evaluated. The relationship between sleep quality and LCD with quantitative variables was assessed by independent sample t‐test and with qualitative variables by chi‐square test. Binary logistic regression was used to estimate confounding variables including age, job, stress, weight to investigate the relationship between LCD and sleep. Following of LCD had a significant negative relationship with PSQI score. It can be said that with increasing LCD adherence, the possibility of poor sleep quality decrease (OR = 0.43, 95% CI = 0.19–0.94,p =.03). It was also showed, hs‐CRP (OR = 0.61, 95% CI = 0.3–1.21, p =.16) and TAC (OR = 0.6, 95% CI = 0.25–1.4, p = 0.24), eliminated the significance of the association and it is possible that they play a mediating role in this relationship Following the LCD can have a positive effect on improving PSQI scores by reduction in inflammatory markers levels. [ABSTRACT FROM AUTHOR]

Aims: Lipid metabolism might be compromised in type 1 diabetes, and the understanding of lipid physiology is critically important. This study aimed to compare the change in plasma lipid concentrations during carbohydrate dietary changes in individuals with type 1 diabetes and identify links to early‐stage dyslipidaemia. We hypothesized that (1) the lipidomic profiles after ingesting low or high carbohydrate diet for 12 weeks would be different; and (2) specific annotated lipid species could have significant associations with metabolic outcomes. Methods: Ten adults with type 1 diabetes (mean ± SD: age 43.6 ± 13.8 years, diabetes duration 24.5 ± 13.4 years, BMI 24.9 ± 2.1 kg/m2, HbA1c 57.6 ± 2.6 mmol/mol) using insulin pumps participated in a randomized 2‐period crossover study with a 12‐week intervention period of low carbohydrate diet (< 100 g carbohydrates/day) or high carbohydrate diet (> 250 g carbohydrates/day), respectively, separated by a 12‐week washout period. A large‐scale non‐targeted lipidomics was performed with mass spectrometry in fasting plasma samples obtained before and after each diet intervention. Longitudinal lipid levels were analysed using linear mixed‐effects models. Results: In total, 289 lipid species were identified from 14 major lipid classes. Comparing the two diets, 11 lipid species belonging to sphingomyelins, phosphatidylcholines and LPC(O‐16:0) were changed. All the 11 lipid species were significantly elevated during low carbohydrate diet. Two lipid species were most differentiated between diets, namely SM(d36:1) (β ± SE: 1.44 ± 0.28, FDR = 0.010) and PC(P‐36:4)/PC(O‐36:5) (β ± SE: 1.34 ± 0.25, FDR = 0.009) species. Polyunsaturated PC(35:4) was inversely associated with BMI and positively associated with HDL cholesterol (p <.001). Conclusion: Lipidome‐wide outcome analysis of a randomized crossover trial of individuals with type 1 diabetes following a low carbohydrate diet showed an increase in sphingomyelins and phosphatidylcholines which are thought to reduce dyslipidaemia. The polyunsaturated phosphatidylcholine 35:4 was inversely associated with BMI and positively associated with HDL cholesterol (p <.001). Results from this study warrant for more investigation on the long‐term effect of single lipid species in type 1 diabetes. [ABSTRACT FROM AUTHOR]

Summary: Nonalcoholic fatty liver disease (NAFLD) is a major cause of chronic liver disease, characterized by hepatic fat accumulation and possible development of inflammation, fibrosis, and cancer. The ketogenic diet (KD), with its drastic carbohydrate reduction, is a now popular weight loss intervention, despite safety concerns on a possible association with fatty liver. However, KDs were also reported to be beneficial on hepatic pathology, with ketone bodies recently proposed as effective modulators of inflammation and fibrosis. If the beneficial impact of weight loss on NAFLD is established, less is known on the effect of macronutrient distribution on such outcome. In a hypocaloric regimen, the latter seems not to be crucial, whereas at higher calorie intake, macronutrient ratio and, theoretically, ketosis, may become important. KDs could positively impact NAFLD for their very low carbohydrate content, and whether ketosis plays an additional role is unknown. Indeed, several mechanisms may directly link ketosis and NAFLD improvement, and elucidating these aspects would pave the way for new therapeutic strategies. We herein aimed at providing an accurate revision of current literature on KDs and NAFLD, focusing on clinical evidence, metabolic pathways involved, and strict categorization of dietary interventions. [ABSTRACT FROM AUTHOR]

Summary: Objective: Macronutrient regulation of hyperphagia and adiposity in Prader‐Willi syndrome (PWS) is poorly understood. We compared fasting and postprandial concentrations of hormones and metabolites in eight PWS children (age 9‐18 years) fed, in random order, low carbohydrate, high‐fat (LC, 15% carb; 65% fat; 20% protein) and low‐fat, high carbohydrate (LF, 65% carb, 15% fat, 20% protein) diets matched for calories and protein. Methods: Participants were randomized to consume either the LC or LF diet during a first hospital admission and the second diet during a subsequent admission. Blood samples were obtained after overnight fasting and 1 hour after a mixed meal. Results: Relative to subjects consuming the LF diet, subjects consuming the LC diet had: lower postprandial insulin concentrations (P = 0.02); higher fasting GLP‐1 AND GIP concentrations and increased postprandial GLP‐1 (P < 0.02); reduced ratio of fasting ghrelin to GLP‐1 (P = 0.0078); increased FFA and fatty acid oxidation, as assessed by concentrations of even‐chain acylcarnitines (P < 0.001); lower fasting TG and TG/HDL ratio (P < 0.01); and higher concentrations of branch chain amino acids (P < 0.01). There were no changes in glucose, PYY, or adiponectin. CRP, AST and ALT were all higher (P < 0.01) on the LC diet. Conclusions: Increases in GLP‐1 with low carbohydrate feeding and reductions in the ratio of ghrelin to GLP‐1 might limit food intake and improve glycaemic control in PWS. Other potential benefits of carbohydrate restriction may include fat mobilization and oxidation and reductions in the TG/HDL ratio, a marker of insulin resistance. However, increases in CRP, AST and ALT necessitate longer‐term studies of low carbohydrate efficacy and safety. [ABSTRACT FROM AUTHOR]

Aim: Derangements in blood lipid and lipoprotein metabolism are one of the leading causes of coronary heart disease (CHD). Therapeutic lifestyle changes such as diet and exercise are often prescribed to improve blood lipid and lipoprotein characteristics, but the efficacy of a telephone‐based health coaching program has not been thoroughly explored. Our purpose was to examine effects of the Our Healthy Heart (OHH) Program on blood lipid and lipoprotein characteristics of individuals with mixed dyslipidaemia. Methods: Cholesterol content of serum very low‐density lipoprotein (VLDL), low‐density lipoprotein (LDL) and high‐density (HDL) subfractions and apolipoprotein concentrations were measured by vertical‐density ultracentrifugation (Vertical Auto Profile (VAP)) from 1522 individuals with mixed dyslipidaemia (age 18–99 years, body mass index (BMI) 25–40, 62.7% female). Telephone‐based health coaching (OHH, n = 722) or standard care (Control, n = 800) was provided for six months followed by VAP to evaluate changes in lipid and lipoprotein concentrations. Controls were obtained from individuals with similar blood lipid/lipoprotein characteristics who did not participate in the OHH Program. Coaches collected baseline self‐reported data on anthropometrics, food intake and exercise. Participants in the OHH group were then prescribed a hypocaloric 500 kcal/day caloric deficit with encouragement to participate in physical activity. A two‐way ANOVA was used to examine differences between groups over time, with results presented as means ± standard deviation. Results: Health coaching significantly decreased serum concentrations of apoB100 (104.5 ± 25.8–94.3 ± 24.8 mg/dL), shifted LDL pattern size from B to A or A/B in over 60% of the OHH group and decreased cholesterol content of all VLDL subfractions (P < 0.05) compared to the control. Conclusions: Telephone‐based health coaching recommendations to reduce dietary energy intake and increase physical activity produced significant improvements in cholesterol content of atherogenic lipoproteins, which are known to increase CHD risk. [ABSTRACT FROM AUTHOR]

A systematic review and meta-analysis were carried out to study the effects of low-carbohydrate diet (LCD) on weight loss and cardiovascular risk factors (search performed on PubMed, Cochrane Central Register of Controlled Trials and Scopus databases). A total of 23 reports, corresponding to 17 clinical investigations, were identified as meeting the pre-specified criteria. Meta-analysis carried out on data obtained in 1,141 obese patients, showed the LCD to be associated with significant decreases in body weight (−7.04 kg [95% CI −7.20/−6.88]), body mass index (−2.09 kg m−2[95% CI −2.15/−2.04]), abdominal circumference (−5.74 cm [95% CI −6.07/−5.41]), systolic blood pressure (−4.81 mm Hg [95% CI −5.33/−4.29]), diastolic blood pressure (−3.10 mm Hg [95% CI −3.45/−2.74]), plasma triglycerides (−29.71 mg dL−1[95% CI −31.99/−27.44]), fasting plasma glucose (−1.05 mg dL−1[95% CI −1.67/−0.44]), glycated haemoglobin (−0.21% [95% CI −0.24/−0.18]), plasma insulin (−2.24 micro IU mL−1[95% CI −2.65/−1.82]) and plasma C-reactive protein, as well as an increase in high-density lipoprotein cholesterol (1.73 mg dL−1[95%CI 1.44/2.01]). Low-density lipoprotein cholesterol and creatinine did not change significantly, whereas limited data exist concerning plasma uric acid. LCD was shown to have favourable effects on body weight and major cardiovascular risk factors; however the effects on long-term health are unknown. [ABSTRACT FROM AUTHOR]

Aim: To compare the impact of low-carbohydrate diets of different fat content to high-carbohydrate low-fat diet on weight and metabolic parameters in obese adolescents. Methods: Fifty-five patients aged 12–18 years with a body mass index (BMI) above the 95th percentile were randomly allocated to one of three isoenergetic diet regimens. Anthropometric and metabolic measurements were taken after overnight fast, at baseline, after the 12-week intervention and after nine month of follow-up. Results: No significant differences were found among the groups in changes in BMI, BMI-percentile, fat percentage, or metabolic markers at the end of the intervention and at the end of follow-up. Insulin level and homeostasis model assessment (HOMA) level decreased significantly at both time points only in the two low carbohydrate diet groups. Conclusion: All diet regimens are associated with a significant reduction in BMI and improvement of some metabolic parameters in obese adolescents. Low-carbohydrate diets apparently have no advantage over high-carbohydrate low-fat diets. The significant drop in insulin level and HOMA in the low carbohydrate diet groups is noteworthy given the increasing frequency of type-2 diabetes as part of metabolic syndrome in children and youth. The impact of low carbohydrate diets in obese and insulin-resistant youth warrants further investigation. [ABSTRACT FROM AUTHOR]

Oolichan grease, a dietary fat prepared from smelt-like fish, is highly prized by north Pacific coast aboriginal cultures. The composition of oolichan grease is unclear, with one report indicating a high 22:6n-3 content consistent with cold-water marine oils, but another reporting a much lower value. We noted that oolichan grease remains solid up to 15 °C, suggesting a low polyunsaturate content. After extracting total lipids from four fresh oolichan fish and four samples of grease, fatty acids were quantitated by high resolution gas chromatography (GC), as were additional samples of fish lipid and grease that were fractionated into triglyceride (TG), phospholipid (PL), and free fatty acids by thin-layer chromatography. In contradistinction to one prior report, we found EPA and DHA in fresh fish total lipids to be 0.9 and 2.2 wt%, respectively, while in the extracted grease, both were reduced to 0.5 wt%. Only the fresh fish PL fraction contained appreciable DHA. The bulk of the grease consisted of saturated fatty acids (30.3 wt%) and mono-unsaturates (55.0 wt%), explaining its high melting point. Excepting its very low omega-6 content (<2 wt%), oolichan grease is quite similar in composition to human adipose TG. Its solid state at environmental temperatures and low peroxidizability index made it suitable for storage and transport, explaining its status as a preferred trade item among regional aboriginal groups. [ABSTRACT FROM AUTHOR]

Background Recent evidence from randomized controlled trials of hypocaloric low carbohydrate diets in people without diabetes has shown that they promote significant weight loss over the short term. There is very little evidence for any effects of reduced carbohydrate intakes on body weight, glycaemia and cardiovascular risk in people with type 2 diabetes. Methods An electronic search was performed using MEDLINE (1966 to March 2007), EMBASE (1988 to March 2007) and Cochrane Central Register of Controlled Trials (1991 to March 2007) using the keywords low carbohydrate, type 2 diabetes and weight loss. Studies including subjects with type 2 diabetes who adopted a reduced carbohydrate weight loss diet were identified. Data were extracted on study design, weight loss, effects on glycaemia and cardiovascular risk and potential adverse effects. Results Six studies investigating the effects of hypocaloric reduced carbohydrate diets in people with type 2 diabetes were identified. The studies were heterogenous and most included small numbers, were short-term and provided varying amounts of carbohydrate. No studies were identified that were both low carbohydrate (<50 g day−1) and also designed as randomized controlled trials. All studies reported reductions in both body weight and glycated haemoglobin, with no deleterious effects on cardiovascular risk, renal function or nutritional intake. Conclusions Conclusions are limited by study design and small numbers, but it appears that reduced carbohydrate diets are safe and effective over the short term for people with type 2 diabetes. [ABSTRACT FROM AUTHOR]