Substituting carbohydrate at lunch for added protein increases fat oxidation during subsequent exercise in healthy males

CONTEXT

How pre-exercise meal composition influences metabolic and health responses to exercise later in the day is currently unclear.

OBJECTIVE

Examine the effects of substituting carbohydrate for protein at lunch on subsequent exercise metabolism, appetite, and energy intake.

METHODS

Twelve healthy males completed three trials in randomized, counterbalanced order. Following a standardized breakfast (779 ± 66 kcal; ∼08:15), participants consumed a lunch (1186 ± 140 kcal; ∼13:15) containing either 0.2 g·kg-1 carbohydrate and ∼2 g·kg-1 protein (LO-CARB), 2 g·kg-1 carbohydrate and ∼0.4 g·kg-1 protein (HI-CARB), or fasted (FAST). Participants later cycled at ∼60% V̇O2peak for 1 h (∼16:15) and post-exercise ad-libitum energy intake was measured (∼18:30). Substrate oxidation, subjective appetite, and plasma concentrations of glucose, insulin, non-esterified fatty acids (NEFA), peptide YY (PYY), glucagon-like peptide-1 (GLP-1), and acylated ghrelin (AG) were measured for 5 h post-lunch.

RESULTS

Fat oxidation was greater during FAST (+11.66 ± 6.63 g) and LO-CARB (+8.00 ± 3.83 g) than HI-CARB (p < 0.001), with FAST greater than LO-CARB (+3.67 ± 5.07 g; p < 0.05). NEFA were lowest in HI-CARB and highest in FAST, with insulin demonstrating the inverse response (all p < 0.01). PYY and GLP-1 demonstrated a stepwise pattern, with LO-CARB greatest and FAST lowest (all p < 0.01). AG was lower during HI-CARB and LO-CARB versus FAST (p < 0.01). Energy intake in LO-CARB was lower than FAST (-383 ± 233 kcal; p < 0.001) and HI-CARB (-313 ± 284 kcal; p < 0.001).

CONCLUSION

Substituting carbohydrate for protein in a pre-exercise lunch increased fat oxidation, suppressed subjective and hormonal appetite, and reduced post-exercise energy intake.

Short-term effect of plant-based Nordic diet versus carbohydrate-restricted diet on glucose levels in gestational diabetes - the eMOM pilot study

BACKGROUND

The optimal nutritional treatment for gestational diabetes (GDM) is still a matter of debate. With increasing rates of GDM and potential negative consequences for the health of mother and child, the best treatment should be established. The Nordic diet with emphasis on plant-based protein show promising health outcomes in other populations but has yet to be investigated in GDM population. The aim of this study, which is part of the "Effect of plant-based Nordic diet versus carbohydrate-restricted diet on glucose levels in gestational diabetes" (eMOM) pilot study was to compare the short-term effects of healthy Nordic diet (HND) and the currently recommended moderate restriction of carbohydrates diet (MCRD) on glucose and lipid metabolism in women with GDM.

METHODS

This was a randomized crossover where each of the diet interventions (HND and MCRD) were consumed for 3 days with a 3-day wash-out period in between. In total, 42 pregnant women diagnosed with GDM (< 29 + 0 gestational week) were randomized. Glucose data was collected by continuous glucose monitors (CGM, Freestyle Libre®, Abbott, USA) worn for 14 days, and participants gave blood samples before and after diet interventions. The primary outcome was time spent in glucose target range (TIR, < 7.8 mmol/L). TIR, 3-day mean tissue glucose as well as changes in fasting glucose, homeostatic model of insulin resistance (HOMA-IR) and blood lipids were analyzed with paired samples statistical analyses.

RESULTS

Thirty-six women with complete 14 days CGM data were analyzed. Both diet interventions produced a high degree of TIR (99% SD 1.8), without a difference between the diets (p = 0.727). The 3-day mean glucose was significantly lower in HND than in MCRD (p = 0,049). Fasting insulin (p = 0,034), insulin resistance (p = 0,030), total and LDL cholesterol (p = 0,023 and 0,008) reduced more in the MCRD diet than the HND. NS differences in any other measure of CGM or blood tests.

CONCLUSIONS

HND and MCRD did not differ in terms of their short-term effect on TIR. A larger study with sufficient power is needed to confirm the differences in short-term mean glucose, insulin resistance and lipid metabolism.

TRIAL REGISTRATION

Registered in clinicaltrials.gov (21/09/2018, NCT03681054).

Effective suppression of myocardial glucose uptake using predesigned low-carbohydrate boxed meals

BACKGROUND

Dietary preparation protocols are an effective means to suppress physiological myocardial 18F-fluorodeoxyglucose (FDG) uptake. This study aimed to investigate the efficacy of various carbohydrate-restricted diets using predesigned boxed meals.

METHODS

The patients were divided into four groups to undergo different preparatory protocols as follows: a minimum 15-hour fast alone, two meals of high-fat, low-carbohydrate diet (HFLCD), two meals of high-animal-protein, low-carbohydrate diet (HAPLCD), and two meals of high-plant-based-protein, low-carbohydrate diet (HPPLCD). Boxed meals were prepared to meet the required carbohydrate restrictions. Myocardial SUVmax and SUVmean were measured and the suppression rate was analyzed.

RESULTS

The average myocardial SUVmax of fast alone, HFLCD, HAPLCD, and HPPLCD were 8.26 ± 5.85, 2.21 ± 1.50, 2.34 ± 1.88, and 4.10 ± 3.61, respectively, and the suppression rates were 36.6%, 93.3%, 93.3%, and 70%, respectively. The effectiveness of HFLCD, HAPLCD, and HPPLCD was all statistically superior to that of a 15-hour fast alone. SUVmax of HFLCD and HAPLCD showed no significant differences (p = 1), whereas HFLCD and HPPLCD had significant differences (p = .046).

CONCLUSIONS

Using the predesigned boxed meals based on carbohydrate restriction, HFLCD, HAPLCD, and HPPLCD can be administered to patients with different dietary needs while providing a substantial reduction in physiological myocardial FDG uptake.

Keto is Trending: Implications for Body Weight and Lipid Management

PURPOSE OF REVIEW

Very-low-carbohydrate (VLC) and ketogenic diets (KDs) have been used for weight loss and more recently in patients with insulin resistance and type 2 diabetes. The impact of VLC and KDs on lipids/lipoproteins is a concern. The purpose of this review is to discuss the impact of KDs on body weight and lipids/lipoproteins.

RECENT FINDINGS

VLC/KDs contribute to greater weight loss in the short term (< 6 months) compared to higher carbohydrate diets, but there is typically no difference between the diets by 12 months. Triglyceride and high-density lipoprotein cholesterol levels generally improve, but there is a variable response in low-density lipoprotein cholesterol levels, with some individuals experiencing a dramatic increase, particularly those with latent genetic dyslipidemias. Healthcare professionals should educate patients on the risks and benefits of following VLC/KDs and encourage the consumption of carbohydrate-rich foods associated with positive health outcomes.

Dietary carbohydrate restriction augments weight loss-induced improvements in glycaemic control and liver fat in individuals with type 2 diabetes: a randomised controlled trial

AIMS/HYPOTHESIS

Lifestyle modification and weight loss are cornerstones of type 2 diabetes management. However, carbohydrate restriction may have weight-independent beneficial effects on glycaemic control. This has been difficult to demonstrate because low-carbohydrate diets readily decrease body weight. We hypothesised that carbohydrate restriction enhances the beneficial metabolic effects of weight loss in type 2 diabetes.

METHODS

This open-label, parallel RCT included adults with type 2 diabetes, HbA_1c 48-97 mmol/mol (6.5-11%), BMI >25 kg/m², eGFR >30 ml min^-1 [1.73 m]^-2 and glucose-lowering therapy restricted to metformin or dipeptidyl peptidase-4 inhibitors. Participants were randomised by a third party and assigned to 6 weeks of energy restriction (all foods were provided) aiming at ~6% weight loss with either a carbohydrate-reduced high-protein diet (CRHP, percentage of total energy intake [E%]: CH30/P30/F40) or a conventional diabetes diet (CD, E%: CH50/P17/F33). Fasting blood samples, continuous glucose monitoring and magnetic resonance spectroscopy were used to assess glycaemic control, lipid metabolism and intrahepatic fat. Change in HbA_1c was the primary outcome; changes in circulating and intrahepatic triacylglycerol were secondary outcomes. Data were collected at Copenhagen University Hospital (Bispebjerg and Herlev).

RESULTS

Seventy-two adults (CD 36, CRHP 36, all white, 38 male sex) with type 2 diabetes (mean duration 8 years, mean HbA_1c 57 mmol/mol [7.4%]) and mean BMI of 33 kg/m² were enrolled, of which 67 (CD 33, CRHP 34) completed the study. Body weight decreased by 5.8 kg (5.9%) in both groups after 6 weeks. Compared with the CD diet, the CRHP diet further reduced HbA_1c (mean [95% CI] -1.9 [-3.5, -0.3] mmol/mol [-0.18 (-0.32, -0.03)%], p = 0.018) and diurnal mean glucose (mean [95% CI] -0.8 [-1.2, -0.4] mmol/l, p < 0.001), stabilised glucose excursions by reducing glucose CV (mean [95% CI] -4.1 [-5.9, -2.2]%, p < 0.001), and augmented the reductions in fasting triacylglycerol concentration (by mean [95% CI] -18 [-29, -6]%, p < 0.01) and liver fat content (by mean [95% CI] -26 [-45, 0]%, p = 0.051). However, pancreatic fat content was decreased to a lesser extent by the CRHP than the CD diet (mean [95% CI] 33 [7, 65]%, p = 0.010). Fasting glucose, insulin, HOMA2-IR and cholesterol concentrations (total, LDL and HDL) were reduced significantly and similarly by both diets.

CONCLUSIONS/INTERPRETATION

Moderate carbohydrate restriction for 6 weeks modestly improved glycaemic control, and decreased circulating and intrahepatic triacylglycerol levels beyond the effects of weight loss itself compared with a CD diet in individuals with type 2 diabetes. Concurrent differences in protein and fat intakes, and the quality of dietary macronutrients, may have contributed to these results and should be explored in future studies.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03814694.

FUNDING

The study was funded by Arla Foods amba, The Danish Dairy Research Foundation, and Copenhagen University Hospital Bispebjerg Frederiksberg.

Low-carbohydrate diets: Effects on metabolism and exercise - A comprehensive literature review

BACKGROUND & AIMS

Low-carbohydrate diets (LCD) have gained substantial attention in recent years for their potential in health promotion and treatment of diseases, but they remain controversial in nutrition guidelines and exercise performance. Herein, through a literature review, we discuss the current evidence base by considering management of LCD and potential coupling of these dietary regiments with physical exercise.

METHODS

We performed a comprehensive literature review with no date limits as a means of including seminal to current studies.

RESULTS

Reduction of CHO intake decreases muscle glycogen, yielding greater fat oxidation and associated metabolic benefits. LCD may promote fat mass loss and regulation of biochemical parameters, such as lipid and glycemic biomarkers. The therapeutic potential of LCD towards noncommunicable diseases, particularly obesity and its comorbidities, is therefore reasonable as a dietary candidate in this context. Potential benefits to this approach are linked to enhancement of mitochondrial gene expression and mitochondrial biogenesis. As such, LCD may be a feasible tool in a 'periodized nutrition' for athletes and within clinical scenarios. Long-term observational follow-up studies have demonstrated increased mortality and cardiovascular implications of LCD. However, harmful associations may depend on the food source (e.g., animal-based vs. plant-based foods).

CONCLUSION

LCD may decrease body mass, waist circumference, and improve fat and carbohydrate metabolism. When combined with exercise, LCD seems to be an effective strategy in regulating metabolic factors of cardiovascular diseases. Conversely, LCD may be associated with higher mortality and metabolic dysregulations if it contains large amounts of animal-based foods, particularly saturated fat.

Effects of protein intake prior to carbohydrate-restricted endurance exercise: a randomized crossover trial

Background

Deliberately training with reduced carbohydrate availability, a paradigm coined training low, has shown to promote adaptations associated with improved aerobic capacity. In this context researchers have proposed that protein may be ingested prior to training as a means to enhance the protein balance during exercise without spoiling the effect of the low carbohydrate availability. Accordingly, this is being practiced by world class athletes. However, the effect of protein intake on muscle protein metabolism during training low has not been studied.

This study aimed to examine if protein intake prior to exercise with reduced carbohydrate stores benefits muscle protein metabolism in exercising and non-exercising muscles.

Methods

Nine well-trained subjects completed two trials in random order both of which included a high-intensity interval ergometer bike ride (day 1), a morning (day 2) steady state ride (90 min at 65% VO₂peak, 90ss), and a 4-h recovery period. An experimental beverage was consumed before 90ss and contained either 0.5 g whey protein hydrolysate [WPH]/ kg lean body mass or flavored water [PLA]. A stable isotope infusion (L-[ring-¹³C₆]-phenylalanine) combined with arterial-venous blood sampling, and plasma flow rate measurements were used to determine forearm protein turnover. Myofibrillar protein synthesis was determined from stable isotope incorporation into the vastus lateralis.

Results

Forearm protein net balance was not different from zero during 90ss exercise (nmol/100 ml/min, PLA: 0.5 ± 2.6; WPH: 1.8, ± 3.3) but negative during the 4 h recovery (nmol/100 ml/min, PLA: − 9.7 ± 4.6; WPH: − 8.7 ± 6.5); no interaction (P = 0.5) or main effect of beverage (P = 0.11) was observed. Vastus lateralis myofibrillar protein synthesis rates were increased during 90ss exercise (+ 0.02 ± 0.02%/h) and recovery (+ 0.02 ± 0.02%/h); no interaction (P = 0.3) or main effect of beverage (P = 0.3) was observed.

Conclusion

We conclude that protein ingestion prior to endurance exercise in the energy- and carbohydrate-restricted state does not increase myofibrillar protein synthesis or improve net protein balance in the exercising and non-exercising muscles, respectively, during and in the hours after exercise compared to ingestion of a non-caloric control.

Trial registration

clinicaltrials.gov, NCT01320449. Registered 10 May 2017 – Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03147001

Carbohydrate restriction in the morning increases weight loss effect of a hypocaloric Mediterranean type diet: a randomized, parallel group dietary intervention in overweight and obese subjects

OBJECTIVE

The aim of this study was to examine the effect of carbohydrate restriction in the morning in the framework of a hypocaloric Mediterranean diet on weight loss and metabolic parameters.

METHODS

Seventy overweight/obese individuals were randomized to two hypocaloric dietary regimens: one Mediterranean diet (Med-D) and one morning carbohydrate-restriction diet (MCR-D). Participants assigned to the MCR-D were permitted to consume a breakfast low in carbohydrate content, whereas typical Mediterranean morning meals were allowed in the Med-D group. Both diets were identical from midday on. Participants were followed over a period of 2 mo.

RESULTS

Individuals in both groups achieved significant reductions in body weight, body mass index, waist circumference, and body fat mass. These reductions were more pronounced in the MCR-D than in the Med-D group (all P < 0.001). More participants in the MCR-D group achieved loss of 5% to 10% of body weight by the end of the first month, as well as 5% to 10% and >10% of body weight by the end of the second month (all P < 0.001). All participants achieved loss of ≥5% baseline body weight by the end of the intervention. Both groups achieved similar reductions in fasting serum glucose, glycated hemoglobin, and serum triacylglycerols as well as improvement in insulin sensitivity. Individuals in the Med-D group showed reductions in total and low-density lipoprotein cholesterol, whereas no such effect was observed in the MCR-D group.

CONCLUSIONS

Integration of morning carbohydrate restriction into a Mediterranean-type hypocaloric diet resulted in greater weight loss while retaining metabolic benefits in glycemia-related parameters.

A carbohydrate-reduced high-protein diet improves HbA1c and liver fat content in weight stable participants with type 2 diabetes: a randomised controlled trial

AIMS/HYPOTHESIS

Dietary recommendations for treating type 2 diabetes are unclear but a trend towards recommending a diet reduced in carbohydrate content is acknowledged. We compared a carbohydrate-reduced high-protein (CRHP) diet with an iso-energetic conventional diabetes (CD) diet to elucidate the effects on glycaemic control and selected cardiovascular risk markers during 6 weeks of full food provision of each diet.

METHODS

The primary outcome of the study was change in HbA_1c. Secondary outcomes reported in the present paper include glycaemic variables, ectopic fat content and 24 h blood pressure. Eligibility criteria were: men and women with type 2 diabetes, HbA_1c 48-97 mmol/mol (6.5-11%), age >18 years, haemoglobin >6/>7 mmol/l (women/men) and eGFR >30 ml min^-1 (1.73 m)^-2. Participants were randomised by drawing blinded ballots to 6 + 6 weeks of an iso-energetic CRHP vs CD diet in an open label, crossover design aiming at body weight stability. The CRHP/CD diets contained carbohydrate 30/50 energy per cent (E%), protein 30/17E% and fat 40/33E%, respectively. Participants underwent a meal test at the end of each diet period and glycaemic variables, lipid profiles, 24 h blood pressure and ectopic fat including liver and pancreatic fat content were assessed at baseline and at the end of each diet period. Data were collected at Copenhagen University Hospital, Bispebjerg and Copenhagen University Hospital, Herlev.

RESULTS

Twenty-eight participants completed the study. Fourteen participants carried out 6 weeks of the CRHP intervention followed by 6 weeks of the CD intervention, and 14 participants received the dietary interventions in the reverse order. Compared with a CD diet, a CRHP diet reduced the primary outcome of HbA_1c (mean ± SEM: -6.2 ± 0.8 mmol/mol (-0.6 ± 0.1%) vs -0.75 ± 1.0 mmol/mol (-0.1 ± 0.1%); p < 0.001). Nine (out of 37) pre-specified secondary outcomes are reported in the present paper, of which five were significantly different between the diets, (p < 0.05); compared with a CD diet, a CRHP diet reduced the secondary outcomes (mean ± SEM or medians [interquartile range]) of fasting plasma glucose (-0.71 ± 0.20 mmol/l vs 0.03 ± 0.23 mmol/l; p < 0.05), postprandial plasma glucose AUC (9.58 ± 0.29 mmol/l × 240 min vs 11.89 ± 0.43 mmol/l × 240 min; p < 0.001) and net AUC (1.25 ± 0.20 mmol/l × 240 min vs 3.10 ± 0.25 mmol/l × 240 min; p < 0.001), hepatic fat content (-2.4% [-7.8% to -1.0%] vs 0.2% [-2.3% to 0.9%]; p < 0.01) and pancreatic fat content (-1.7% [-3.5% to 0.6%] vs 0.5% [-1.0% to 2.0%]; p < 0.05). Changes in other secondary outcomes, i.e. 24 h blood pressure and muscle-, visceral- or subcutaneous adipose tissue, did not differ between diets.

CONCLUSIONS/INTERPRETATION

A moderate macronutrient shift by substituting carbohydrates with protein and fat for 6 weeks reduced HbA_1c and hepatic fat content in weight stable individuals with type 2 diabetes.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02764021.

FUNDING

The study was funded by grants from Arla Food for Health; the Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen; the Department of Clinical Medicine, Aarhus University; the Department of Nutrition, Exercise and Sports, University of Copenhagen; and Copenhagen University Hospital, Bispebjerg.

Dietary restriction regimens for fighting kidney disease: Insights from rodent studies

This review critically discusses the research findings on the effects of various dietary restriction regimens in rodent models of kidney disease. Long-term caloric restriction executed at both early and progressive stages of kidney disease was found to exert beneficial effects in rodents. Moreover, some studies have also demonstrated the efficacy of short-term caloric restriction in treating the kidney disease of variable aetiologies possibly by improving mitochondrial dysfunction, autophagy process and suppression of inflammation. However, the mechanisms underlying these short-term caloric restriction mediated protective effects in rodent models of kidney disease are not completely understood. Importantly, few available evidences have also suggested that carbohydrate restriction can exert beneficial effects in aging and experimentally induced renal injury models, but the mechanisms are not explored yet. Interestingly, the benefits of low protein diet in kidney disease models are extensively reported in literature. However, in most of these studies implementation of the low protein dietary regimen was found to associated with increased high carbohydrate and caloric intake (non-isocaloric). Thus, testing the effects of low protein diet under isocaloric conditions might further help to particularly understand the role of dietary protein content in pathology of kidney disease. Moreover, the direct evidences comparing the efficacy of various dietary restriction regimens in rodent models of kidney diseases are also scarce at present.

Introducing a very low carbohydrate diet for a child with type 1 diabetes

Type 1 diabetes mellitus is a serious autoimmune disease for which no cure is available. The treatment includes insulin therapy, carbohydrate counting, eating healthy foods, exercising regularly, and maintaining a healthy weight. The goal is to keep blood glucose levels close to normal most of the time to delay or prevent complications. Despite the increase in the use of insulin pumps and continuous glucose monitors in recent years, the management of type 1 diabetes remains suboptimal in terms of glycaemic control and normal glycated haemoglobin (HbA1c) level. This article discusses the case of a child with type 1 diabetes who was successfully treated with a very low-carbohydrate diet, resulting in normal levels of HbA1c and normal blood glucose 95% of the time in a range of 70-180 mg/dL (4.0 mmol/L-10 mmol/L). Therefore, further studies are needed to verify how a very low carbohydrate diet impacts child development.

Nutritional ketosis for mild cognitive impairment in Parkinson's disease: A controlled pilot trial

INTRODUCTION

Glucose hypometabolism and insulin resistance increase risk for and accelerate progression in Parkinson's disease and neurocognitive disorders. We conducted a proof of concept trial to determine whether ketogenesis, a metabolic adaptation induced by dietary carbohydrate restriction, can improve cognitive performance in Parkinson's disease patients with mild cognitive impairment.

METHODS

We enrolled patients with mild cognitive impairment associated with Parkinson's disease in an eight-week nutritional intervention with random assignment to either high-carbohydrate consumption typical of the Western dietary pattern (n = 7) or to a low-carbohydrate, ketogenic regimen (n = 7). We assessed changes in cognitive performance as well as motor function, anthropometrics, and metabolic parameters.

RESULTS

Relative to the high-carbohydrate group, the low-carbohydrate group demonstrated improvements in lexical access (p = 0.02, Cohen's f effect size = 0.76) and memory (p = 0.01, f = 0.87) and as well as a trend for reduced interference in memory (p = 0.06, f = 0.60). The low-carbohydrate group also exhibited reduced body weight (p < 0.0001, f = 1.89) and increased circulation of beta-hydroxybutyrate (p = 0.01, f = 0.90). Change in body weight was strongly associated with memory performance (p = 0.001). Motor function was not affected by the intervention.

CONCLUSION

Nutritional ketosis enhanced cognitive performance in Parkinson's disease-associated mild cognitive impairment in this pilot study. This metabolic intervention and its mechanisms deserve further investigation in the context of neurodegeneration.

Low-carbohydrate diets differing in carbohydrate restriction improve cardiometabolic and anthropometric markers in healthy adults: A randomised clinical trial

Background

Low-carbohydrate, high-fat (LCHF) diets are useful for treating a range of health conditions, but there is little research evaluating the degree of carbohydrate restriction on outcome measures. This study compares anthropometric and cardiometabolic outcomes between differing carbohydrate-restricted diets.

Objective

Our hypothesis was that moderate carbohydrate restriction is easier to maintain and more effective for improving cardiometabolic health markers than greater restriction.

Design

A total of 77 healthy participants were randomised to a very low-carbohydrate ketogenic diet (VLCKD), low-carbohydrate diet (LCD), or moderate-low carbohydrate diet (MCD), containing 5%, 15% and 25% total energy from carbohydrate, respectively, for 12-weeks. Anthropometric and metabolic health measures were taken at baseline and at 12 weeks. Using ANOVA, both within and between-group outcomes were analysed.

Results

Of 77 participants, 39 (51%) completed the study. In these completers overall, significant reductions in weight and body mass index occurred ((mean change) 3.7 kg/m²; 95% confidence limits (CL): 3.8, 1.8), along with increases in high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, (0.49 mmol/L; 95% CL; 0.06, 0.92; p = 0.03), and total cholesterol concentrations (0.11 mmol/L; 95% CL; 0.00, 0.23; p = 0.05). Triglyceride (TG) levels were reduced by 0.12 mmol/L (95% CL; −0.20, 0.02; p = 0.02). No significant changes occurred between groups. The largest improvements in high density lipoprotein cholesterol (HDL-c) and TG and anthropometric changes occurred for the VLCKD group.

Conclusions

Low-carbohydrate, high-fat diets have a positive effect on markers of health. Adherence to the allocation of carbohydrate was more easily achieved in MCD, and LCD groups compared to VLCKD and there were comparable improvements in weight loss and waist circumference and greater improvements in HDL-c and TG with greater carbohydrate restriction.

Cardiovascular disease risk factor responses to a type 2 diabetes care model including nutritional ketosis induced by sustained carbohydrate restriction at 1 year: an open label, non-randomized, controlled study

BACKGROUND

Cardiovascular disease (CVD) is a leading cause of death among adults with type 2 diabetes mellitus (T2D). We recently reported that glycemic control in patients with T2D can be significantly improved through a continuous care intervention (CCI) including nutritional ketosis. The purpose of this study was to examine CVD risk factors in this cohort.

METHODS

We investigated CVD risk factors in patients with T2D who participated in a 1 year open label, non-randomized, controlled study. The CCI group (n = 262) received treatment from a health coach and medical provider. A usual care (UC) group (n = 87) was independently recruited to track customary T2D progression. Circulating biomarkers of cholesterol metabolism and inflammation, blood pressure (BP), carotid intima media thickness (cIMT), multi-factorial risk scores and medication use were examined. A significance level of P < 0.0019 ensured two-tailed significance at the 5% level when Bonferroni adjusted for multiple comparisons.

RESULTS

The CCI group consisted of 262 participants (baseline mean (SD): age 54 (8) year, BMI 40.4 (8.8) kg m-2). Intention-to-treat analysis (% change) revealed the following at 1-year: total LDL-particles (LDL-P) (- 4.9%, P = 0.02), small LDL-P (- 20.8%, P = 1.2 × 10-12), LDL-P size (+ 1.1%, P = 6.0 × 10-10), ApoB (- 1.6%, P = 0.37), ApoA1 (+ 9.8%, P < 10-16), ApoB/ApoA1 ratio (- 9.5%, P = 1.9 × 10-7), triglyceride/HDL-C ratio (- 29.1%, P < 10-16), large VLDL-P (- 38.9%, P = 4.2 × 10-15), and LDL-C (+ 9.9%, P = 4.9 × 10-5). Additional effects were reductions in blood pressure, high sensitivity C-reactive protein, and white blood cell count (all P < 1 × 10-7) while cIMT was unchanged. The 10-year atherosclerotic cardiovascular disease (ASCVD) risk score decreased - 11.9% (P = 4.9 × 10-5). Antihypertensive medication use was discontinued in 11.4% of CCI participants (P = 5.3 × 10-5). The UC group of 87 participants [baseline mean (SD): age 52 (10) year, BMI 36.7 (7.2) kg m-2] showed no significant changes. After adjusting for baseline differences when comparing CCI and UC groups, significant improvements for the CCI group included small LDL-P, ApoA1, triglyceride/HDL-C ratio, HDL-C, hsCRP, and LP-IR score in addition to other biomarkers that were previously reported. The CCI group showed a greater rise in LDL-C.

CONCLUSIONS

A continuous care treatment including nutritional ketosis in patients with T2D improved most biomarkers of CVD risk after 1 year. The increase in LDL-cholesterol appeared limited to the large LDL subfraction. LDL particle size increased, total LDL-P and ApoB were unchanged, and inflammation and blood pressure decreased. Trial registration Clinicaltrials.gov: NCT02519309. Registered 10 August 2015.

Effectiveness and Safety of a Novel Care Model for the Management of Type 2 Diabetes at 1 Year: An Open-Label, Non-Randomized, Controlled Study

INTRODUCTION

Carbohydrate restriction markedly improves glycemic control in patients with type 2 diabetes (T2D) but necessitates prompt medication changes. Therefore, we assessed the effectiveness and safety of a novel care model providing continuous remote care with medication management based on biometric feedback combined with the metabolic approach of nutritional ketosis for T2D management.

METHODS

We conducted an open-label, non-randomized, controlled, before-and-after 1-year study of this continuous care intervention (CCI) and usual care (UC). Primary outcomes were glycosylated hemoglobin (HbA1c), weight, and medication use. Secondary outcomes included fasting serum glucose and insulin, HOMA-IR, blood lipids and lipoproteins, liver and kidney function markers, and high-sensitivity C-reactive protein (hsCRP).

RESULTS

349 adults with T2D enrolled: CCI: n = 262 [mean (SD); 54 (8) years, 116.5 (25.9) kg, 40.4 (8.8) kg m2, 92% obese, 88% prescribed T2D medication]; UC: n = 87 (52 (10) years, 105.6 (22.15) kg, 36.72 (7.26) kg m2, 82% obese, 87% prescribed T2D medication]. 218 participants (83%) remained enrolled in the CCI at 1 year. Intention-to-treat analysis of the CCI (mean ± SE) revealed HbA1c declined from 59.6 ± 1.0 to 45.2 ± 0.8 mmol mol-1 (7.6 ± 0.09% to 6.3 ± 0.07%, P < 1.0 × 10-16), weight declined 13.8 ± 0.71 kg (P < 1.0 × 10-16), and T2D medication prescription other than metformin declined from 56.9 ± 3.1% to 29.7 ± 3.0% (P < 1.0 × 10-16). Insulin therapy was reduced or eliminated in 94% of users; sulfonylureas were entirely eliminated in the CCI. No adverse events were attributed to the CCI. Additional CCI 1-year effects were HOMA-IR - 55% (P = 3.2 × 10-5), hsCRP - 39% (P < 1.0 × 10-16), triglycerides - 24% (P < 1.0 × 10-16), HDL-cholesterol + 18% (P < 1.0 × 10-16), and LDL-cholesterol + 10% (P = 5.1 × 10-5); serum creatinine and liver enzymes (ALT, AST, and ALP) declined (P ≤ 0.0001), and apolipoprotein B was unchanged (P = 0.37). UC participants had no significant changes in biomarkers or T2D medication prescription at 1 year.

CONCLUSIONS

These results demonstrate that a novel metabolic and continuous remote care model can support adults with T2D to safely improve HbA1c, weight, and other biomarkers while reducing diabetes medication use. CLINICALTRIALS.

GOV IDENTIFIER

NCT02519309.

FUNDING

Virta Health Corp.

Effectiveness of a carbohydrate restricted diet to treat non-alcoholic fatty liver disease in adolescents with obesity: Trial design and methodology

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is the most common liver disorder among children in the developed world and can progress to cirrhosis, hepatocellular carcinoma, and liver failure. No evidence-based dietary guidelines exist on the most effective diet prescription to treat NAFLD.

OBJECTIVE

To compare the effect of a carbohydrate (CHO)-restricted diet vs fat-restricted diet, the current standard of care, on changes in hepatic fat infiltration, body composition, and metabolic health over an 8-week period among overweight and obese children diagnosed with NAFLD.

METHODS

In this two-arm, parallel design randomized controlled trial (RCT), 40 participants aged 9 to 18 years were randomized to a CHO restricted diet (<25:>50:25% daily calories from CHO: fat: protein) or control, fat restricted diet (55,20:25% daily calories from CHO: fat: protein). This family-based diet intervention included: (1) a 2-week supply of groceries to feed a four-person household specific to the assigned diet; and (2) extensive education on diet implementation through biweekly, diet-specific group and individualized counseling sessions with participants and one parent or guardian led by a registered dietitian (RD). The primary outcome measure of this study was hepatic lipid, measured using magnetic resonance spectroscopy (MRS). Secondary outcomes included liver transaminases; markers of inflammation (hsCRP, IL-6, TNF-α); body composition; visceral adipose tissue; and insulin resistance. All testing was conducted at baseline and week 8; hepatic transaminases were also measured at weeks 2 and 4. This RCT is registered with ClinicalTrials.gov (ID: NCT02787668).

A shift toward a high-fat diet in the current metabolic paradigm: A new perspective

OBJECTIVE

Investigations into the relationship between dietary carbohydrate restriction and health are mixed. Current guidelines for nutrition promote low-fat foods and higher carbohydrate consumption for optimal health and weight loss. However, high-fat, low-carbohydrate diets are revealing both intra- and extracellular adaptations that have been shown to elicit favorable cardiometabolic changes associated with obesity. Moreover, dietary fat is associated with higher satiety levels from the hormones adiponectin, leptin, and cholecystokinin. Additionally, insulin responses from high-glycemic carbohydrates are known to alter these pathways, potentially leading to an increase in energy consumption and a possible mechanism for obesity.

CONCLUSION

There is convincing evidence of beneficial effects of controlled trials implementing high-fat, low-carbohydrate diets in both sedentary and obese individuals, but longer duration clinical trials are required to confirm this hypothesis.

Carbohydrate restriction ameliorates nephropathy by reducing oxidative stress and upregulating HIF-1α levels in type-1 diabetic rats

Background

Carbohydrate restricted diet regimen is widely accepted as therapeutic approach for the treatment of kidney disease associated with type-2 diabetes, obesity and hypertensive disorders. The present study tested the influence of carbohydrate-energy restricted diet (CR) on type-1 diabetes induced renal dysfunction, hypoxia and structural alterations against diabetic rat group fed control diet (ad libitium).

Methods

Male wistar rats weighing between 180 and 190 g were subjected to 30% carbohydrate energy restricted diet (CR) and diabetes was induced by administration of streptozotocin (45 mg/kg., i.p). Assessment of renal function was done after 4 weeks by determining the serum levels of creatinine, BUN, proteinuria. Oxidative stress was determined by estimating the reduced glutathione, malonaldehyde levels, catalase activity and extent of renal hypoxia by estimating the HIF-1α levels in kidney tissue homogenates. Histological studies were conducted on kidney sections using hematoxylin and eosin, periodic acid-schiff staining.

Results

Diabetic rats exhibited marked hyperglycemia and renal dysfunction developed in diabetic rats fed control diet (ad libitium) as shown by significantly elevated levels of serum creatinine, BUN and massive proteinuria after 4 weeks period. CR diet treatment in diabetic rats significantly lowered hyperglycemia, reversed the above renal functional abnormalities, reduced oxidative stress and enhanced HIF-1α levels. Furthermore histological examination of kidney sections from CR diet treated diabetic rat group showed absence of glomerular hypertrophy, mesangial expansion and tubular vacoulations.

Conclusion

Our results demonstrated that CR diet treatment in diabetic rats attenuated renal damage by reducing oxidative stress and preventing the development of hypoxia by up-regulating HIF-1α levels.

Dietary therapy in heart failure with preserved ejection fraction and/or left ventricular diastolic dysfunction in patients with metabolic syndrome

BACKGROUND

Heart failure is an ongoing epidemic of left ventricular (LV) dilatation and/or dysfunction due to the increasing prevalence of predisposing risk factors such as age, physical inactivity, (abdominal) obesity, and type-2-diabetes. Approximately half of these patients have diastolic heart failure (HFpEF). The prognosis of HFpEF is comparable to that of systolic heart failure, but without any known effective treatment.

DIASTOLIC DYSFUNCTION

A biomathematically corrected diagnostic approach is presented that quantifies diastolic dysfunction via the predominant age dependency of LV diastolic function and unmasks (metabolic) risk factors, that are independent of age and, therefore, potential targets for therapy. Patients with HFpEF have reduced cardiac energy reserve that is frequently caused by insulin resistance. Consequently, HFpEF and/or LV diastolic dysfunction may be regarded as a cardiac manifestation of the metabolic syndrome (MetS).

DIETARY THERAPY

Accordingly, a causal therapy for metabolically induced dysfunction aims at normalizing insulin sensitivity by improving postprandial glucose and lipid metabolism. The respective treatments include 1) weight loss induced by dietary energy restriction that is often not sustained long-term and 2) independent of weight loss, focus on carbohydrate modification in exchange for an increase in protein and fat, ideally combined with an aerobic exercise program. Hence, beneficial effects of different macronutrient compositions in the dietary therapy of the underlying MetS are discussed together with the most recently available publications and meta-analyses.

CONCLUSION

Modulation/restriction of carbohydrate intake normalizes postprandial hyperglycemic and insulinemic peaks and has been shown to improve all manifestations of the MetS and also to reduce cardiovascular risk.

Evaluation of carbohydrate restriction as primary treatment for post-gastric bypass hypoglycemia

BACKGROUND

Up to 15% of patients who have undergone Roux-en-Y gastric bypass (RYGB) surgery may eventually develop symptoms of hypoglycemia.

OBJECTIVES

To evaluate the daily life efficacy of a carbohydrate (carb)-restricted dietary advice (CRD) of 6 meals per day with a 30 g carb maximum per meal in patients with documented post-RYGB hypoglycemia.

SETTING

Teaching hospital, the Netherlands.

METHODS

Frequency and severity of hypoglycemic events before and after CRD were assessed retrospectively in 41 patients with documented post-RYGB hypoglycemia, based on medical records and telephone questionnaires. Hypoglycemia was defined as a blood glucose level<3.0 mmol/L. Results are expressed as mean values±standard error or median and range.

RESULTS

CRD decreased the number of hypoglycemic events per month from 17.1 (1.5-180) to 2.5 (0-180), i.e., a decline of 85% (P<.001). The lowest blood glucose measured during a hypoglycemic event increased from 2.1±.4 to 2.6±.2 mmol/L (P = .004). The number of patients who had required outside help in the treatment of hypoglycemia, decreased from 23 to 6 (P<.001). In 14 patients (34.1%) the diet-induced reduction of hypoglycemia was insufficient and required the start of insulin suppressive therapy.

CONCLUSION

A CRD, consisting of 6 meals per day with up to 30 g carbs each, is an effective treatment of post-RYGB hypoglycemia in the majority of patients. Additional medication is needed in about a third of patients.

Cardiometabolic Syndrome and Increased Risk of Heart Failure

Approximately 50 % of patients with heart failure have diastolic heart failure (HFPEF) with the major predisposing risk factors age, inactivity, obesity, insulin resistance (IR), type-2 diabetes, and hypertension. The prognosis of HFPEF is comparable to that of systolic heart failure, but without any specific or effective treatment. This review presents a biomathematically corrected diagnostic approach for quantification of diastolic dysfunction (DD) via the age dependency of diastolic function. Pathophysiological mechanisms for DD in the cardiometabolic syndrome (CMS) are mainly based on downstream effects of IR including insufficient myocardial energy supply. The second section discusses therapeutic strategies for the control and therapy of CMS, IR, and the associated DD/HFPEF with a focus on dietary therapy that is independent of weight loss but improves all manifestations of the CMS and reduces cardiovascular risk.

The effects of small sized rice bowl on carbohydrate intake and dietary patterns in women with type 2 diabetes

Background

The main source of carbohydrate in the Korean diet is rice, which is usually served in a rice bowl. This study investigated the impact of a meal plan using smaller rice bowls on dietary energy intake and macronutrient composition in overweight or obese patients with type 2 diabetes mellitus.

Methods

A total of 67 women with type 2 diabetes were enrolled in our study. We divided these participants into three groups: a normal-weight group (NW; body mass index [BMI] < 23 kg/m²; n = 17), an overweight group (OW; 23 ≤ BMI < 25 kg/m²; n = 24) and an obese group (OB; BMI ≥ 25 kg/m²; n = 26). Three-day dietary records were analyzed for total energy intake (TEI) and macronutrient composition both before enrollment and two weeks after patients received instruction in a dietary plan based on using a small (200 mL) rice bowl.

Results

After the intervention, TEI decreased in the OW and OB groups. Decreased carbohydrate (NW, -4 ± 5%; OW, -4 ± 5%; OB, -3 ± 6%) and increased fat intakes were found in all three groups, which complies with Korean Diabetes Association recommendations. The protein proportion of TEI significantly increased only in the OW group. Body weight decreased both in the OW and OB groups.

Conclusion

A short-term, small-rice-bowl-based meal plan was effective for body weight control and macronutrient balance in overweight or obese women in Korea with type 2 diabetes.