Low-protein High-carbohydrate Diet Research Articles

EFFECT OF HIGH PROTEIN DIET IN ACTIVITY OF ANTIOXIDANTS AND LEVEL OF INFLAMMATION ON SPRINT ATHLETE

This study aims to analyze the effect of a low-carbohydrate high-protein diet to increase the level of antioxidant, decrease inflammation and improve performance of athlete. The research was carried out by experimental research methods, within the design of "Randomized Control Group Pretest Posttest Design".A sample was taken from 20 people who met the inclusion and exclusion criteria from 30 teenage athletes in PASI East Java sprints. The Data were collected by measuring the sprint results by finish photo camera and laboratory examinations to determine the levels of antioxidants (SOD) and the inflammation degree (TNF α)in blood. The data were analyzed using multivariate technique (Manova) Hotelling's method (T2). Hypothesis testing using α0.05. The results and conclusions of the study stated that the normal diet had no effect on the variables of sprint running speed, SOD and TNF-α levels. While low-carbohydrate and high-protein diet can increase SOD levels of 211.44 /gHb, reduce (TNF α) at least 0.309 pg/ml, and the average increase in antioxidant activity caused by low-carbohydrate-high-protein diet is 24,989 / gHb higher than normal diet, the decrease in the degree of inflammation is 0.196 pg/ml, however, it has no effect on the speed of sprint.

Effect of high protein diet in activity of antioxidants and level of inflammation on sprint athlete

This study aims to analyze the effect of a low-carbohydrate high-protein diet to increase the level of antioxidant, decrease inflammation and improve performance of athlete. The research was carried out by experimental research methods, within the design of “Randomized Control Group Pretest Posttest Design”. A sample was taken from 20 people who met the inclusion and exclusion criteria from 30 teenage athletes in PASI East Java sprints. The Data were collected by measuring the sprint results by finish photo camera and laboratory examinations to determine the levels of antioxidants (SOD) and the inflammation degree (TNF-α) in blood. The data were analyzed using multivariate technique (Manova) Hotelling’s method (T2). Hypothesis testing using α = 0.05. The results and conclusions of the study stated that the normal diet had no effect on the variables of sprint running speed, SOD and TNF-α levels. While low-carbohydrate and high-protein diet can increase SOD levels of 211.44/gHb, reduce (TNF-α) at least 0.309 pg/ml, and the average increase in antioxidant activity caused by low-carbohydrate-high-protein diet is 24.989/gHb higher than normal diet, the decrease in the degree of inflammation is 0.196 pg/ml, however, it has no effect on the speed of sprint.

No adverse effect of a maternal high carbohydrate diet on their offspring, in rainbow trout (Oncorhynchus mykiss).

In order to develop a sustainable salmonid aquaculture, it is essential to continue to reduce the use of the protein-rich fishmeal. One promising solution to do so is the use of plant-derived carbohydrates in diet destined to broodstock. However, in mammals, the reduction of protein content (replaced by carbohydrates) in parental diet is known to have strong adverse effects on offspring phenotypes and metabolism. For the first time, the effect of a paternal and a maternal high carbohydrate-low protein diet was assessed on progeny at long term in the rainbow trout. A 30% protein diminution in both males and females broodstock diet during 10 month and 5 months, respectively, did not trigger adverse consequences on their offspring. At the molecular level, offspring transcriptomes were not significantly altered, emphasizing no effect on metabolism. Tenuous differences in the biochemical composition of the liver and the viscera were observed. The recorded effects remained in the normal range of value and accordingly offspring growth were not negatively affected over the long term. Overall, we demonstrated here that a 30% protein diminution during gametogenesis is feasible, confirming the possibility to increase the proportion of plant-derived carbohydrates in female broodstock diets to replace fishmeal proteins.

Abstract P435: Probiotic Supplements Could Prevent Diet-induced Mitochondrial Dysfunction In The Liver Hepatocytes Of Apolipoprotein-e Knockout Mice

A poor diet can modify the intestinal microbiota, known as gut dysbiosis, which causes hepatocyte mitochondrial dysfunction through the release of endotoxins in the portal vein. Mitochondrial dysfunction in the liver leads to non-alcoholic fatty liver disease (NAFLD). Epidemiological evidence shows that most deaths from NAFLD are related to cardiovascular diseases (CVD) demonstrated by impaired vasodilatation as well as increased arterial stiffness, calcification, inflammation, and intimal-medial thickness. Therefore, the objective of our study was to investigate the potential of probiotic supplements to prevent a diet-induced mitochondrial dysfunction in hepatocytes. Apolipoprotein-E knockout mice—genetically modified animals that develop dyslipidemia—were placed in 3 diet groups including a control, western style (high in fats and carbohydrates), as well as a low-carbohydrate high-protein diet. Each group was then further divided in 3 subgroups based on the dose of probiotics administered, including a control, low (0.5 B/dose) and high (5 B/dose) dose of probiotics, for a total of 9 groups (n= 8-12 animals/group). The probiotic supplements contained a 1:1 ratio of Lactobacillus Helveticus and Bifidobacterium Bifidum . The bodyweight and water intake were monitored weekly. After 6 weeks, the liver mitochondria were analyzed by high resolution respirometry using a sequential substrate addition protocol (malate, octanoylcarnitine, ADP, glutamate, pyruvate, cytochrome C, succinate and FCCP) to investigate mitochondrial maximal respiration, leak, membrane damage and uncoupling. Our preliminary results show that the groups that received a high dose of probiotics gained less weight, had a higher respiration following the addition of ADP (a biomarker of complex V efficiency) and a lower respiration following FCCP (a biomarker of mitochondrial uncoupling), as compared to control. Supplements of probiotics could promote weight loss and prevent a diet-induced mitochondrial dysfunction in liver hepatocytes, an important risk factor for NAFLD and therefore, CVD. This project could translate into future research directions in preventative medicine, for example by investigating the potential of probiotics in the prevention of mitochondrial dysfunction in other organs, including the heart and the vascular system.

Short-Term Effect of a Low-Protein High-Carbohydrate Diet on Mature Female and Male, and Neomale Rainbow Trout.

Rainbow trout are considered as a poor user of dietary carbohydrates, displaying persistent postprandial hyperglycaemia when fed a diet containing high amounts of carbohydrates. While this phenotype is well-described in juveniles, less attention was given to broodstock. Our objective was to assess for the first time the short-term consequences of feeding mature female and male, and neomale trout with a low-protein high-carbohydrate diet on glucose and lipid metabolism. Fish were fed for two days with a diet containing either no or 32% of carbohydrates. We analysed plasma metabolites, mRNA levels and enzymatic activities of glycolysis, gluconeogenesis, de novo lipogenesis and β-oxidation in the liver. Results demonstrated that the glucose and lipid metabolism were regulated by the nutritional status in all sexes, irrespective of the carbohydrate intake. These data point out that carbohydrate intake during a short period (5 meals) at 8 °C did not induce specific metabolic changes in broodstock. Finally, we demonstrated, for the first time, sex differences regarding the consequences of two days of feeding on glucose and lipid metabolism.

Utilizing a Low-Carbohydrate/High-Protein Diet to Improve Metabolic Health in Individuals With Spinal Cord Injury

Abstract Objectives The purpose of this study is to determine if an 8-week low-carbohydrate/high-protein (LC/HP) dietary intervention will show improvements in clinically important metrics of metabolic function and body composition in individuals with spinal cord injury (SCI). Methods Twenty-one participants with long-standing SCI (≥3 years post-injury) (age: 45 ± 13 years) were randomly assigned to an 8-week iso-caloric high-protein/low-carbohydrate (HPLC) diet or their habitual control diets. Injury levels ranged between cervical vertebrate 4 to lumbar vertebrate 3. The HPLC diet included ∼30% total energy as protein (40% energy from carbohydrate) and participants were provided with all study meals if they were assigned to the HPLC group. Each participant underwent an oral glucose tolerance test (OGTT) and DXA scanning before and after the intervention after an overnight fast. Blood glucose and insulin during the OGTT were assessed, and their respective incremental areas under the curve were calculated, as well as Matsuda index, an indicator of insulin sensitivity. The blood lipid panel was analyzed using the fasting samples. A two-way repeated-measures ANOVA model was used to evaluate the main effect of diet, time, and their interaction. Results We observed no main effect of time, diet, and their interaction on the fasting concentrations of glucose, insulin, their respective concentrations at 120-minute during the OGTT, and areas under the curve, but a trend for decreased insulin AUC among participants in the HPLC group (P = 0.07). There is a trend for the diet by time interaction effect for the Matsuda index (P = 0.11). The Matsuda index quantitatively increased in the HPLC group while remained in the control group. In contrast, an interaction effect was observed for several outcomes. These outcomes were decreased in the HPLC group, and include total Cholesterol (−23.9mg/dL), LDL (−15.8 mg/dL), total body fat mass (−5%), and visceral fat mass (−11%) (P < 0.05 for all). Fat-free mass did not change over time. Conclusions Our results support that our HPLC diet can be safely adopted by individuals with SCI to achieve improvements in glucose metabolism and lipid profile and body composition. Funding Sources The study was funded by the National Institute on Disability, Independent Living, and Rehabilitation Research (#90SI5019).

A serum metabolomics study on the intervention of nonalcoholic fatty liver disease by equicaloric low-carbohydrate high-protein diet combined with aerobic exercise

Objective To collect the serum samples of patients with nonalcoholic fatty liver disease (NAFLD), and to investigate the changes in serum metabolic biomarkers before and after lifestyle intervention. Methods A total of 23 patients who were diagnosed with NAFLD in Department of Gastroenterology and Inpatient Department, Putuo District Central Hospital of Shanghai, from January 2019 to January 2020 were enrolled, and all patients received the intervention with aerobic exercise and equicaloric low-carbohydrate high-protein diet. A total of 13 healthy volunteers who underwent physical examination in Physical Examination Center were enrolled as control group. For the patients with NAFLD, basic information was collected before and after intervention, blood samples were collected twice to measure liver function, blood glucose, and blood lipids, and part of serum was used for serum metabolomics analysis. The serum samples were analyzed by ultra-performance liquid chromatography/tandem high-resolution mass spectrometry. The data collected were processed in Compound Discover, and then principal component analysis (PCA) and orthogonal partial least squares discriminant analysis were used to establish the profile of differentially expressed blood metabolites between patients and healthy people and perform the enrichment analysis of differentially expressed metabolic pathways. The independent samples t-test was used for comparison of normally distributed continuous data between two groups, and the Wilcoxon non-parametric test was used for comparison of non-normally distributed continuous data between two groups. Results After lifestyle intervention, the patients had significant reductions in body mass index (P Conclusion Lifestyle intervention can achieve varying degrees of reduction in the body weight of patients with NAFLD, improve serum biochemical parameters, and regulate the abnormal metabolic pathway in patients with NAFLD, which has important clinical value and significance for guiding clinicians to formulate reasonable diet and exercise strategies for patients with NAFLD and prevent the progression of NAFLD.

Comparing the Effects of Low-Protein and High-Carbohydrate Diets and Caloric Restriction on Brain Aging in Mice

The Geometric Framework for Nutrition (GFN) has revealed that ad-libitum low-protein, high-carbohydrate (LPHC) diets improve cardiometabolic health and extend lifespan in rodents, but it is not known whether these diets are also beneficial for brain health. Here, we utilized previous results from GFN studies and compared hippocampus biology and memory in mice subjected to 20% calorie restriction (CR) or provided ad-libitum access to several LPHC diets. RNA expression in the hippocampus of 15-month-old mice were similar between mice fed CR and LPHC diets. Nutrient-sensing proteins, including SIRT1, MTOR, and PGC1-alpha, were also influenced by diet; however, the effects varied by sex. CR and LPHC diets were associated with increased dendritic spines in dentate gyrus neurons. Mice fed CR and LPHC diets had modest improvements in the Barnes maze spatial recognition memory paradigm and novel object recognition test. LPHC diets recapitulate some of the benefits of CR on brain aging. Part of a symposium sponsored by the Nutrition Interest Group.

Differential Responses to Dietary Protein and Carbohydrate Ratio on Gut Microbiome in Obese vs. Lean Cats.

More than 60% of domestic cats in the United States are either overweight or obese (OW). High-protein low-carbohydrate (HPLC) diets have been recommended for weight management for humans and pets. Gut microbes can influence the host’s health and metabolism. Less is known about feline gut microbiomes compared to other species. Thirty-nine lean (LN) and OW domestic short-haired cats (median age, 7.2 years) with median body fat of 15.8 and 32.5%, respectively, were enrolled in a two-phase study. All cats were fed the control diet (CON) with 32.4% protein and 32.3% carbohydrate for 8 weeks followed by another 8 weeks of intervention where half of the cats continued the CON diet while the other half were switched to a HPLC diet with 51.4% protein and 11.6% carbohydrate. The goal was to understand how the HPLC diet influenced gut microbiota in obese vs. lean cats. The 16S rRNA gene profiling study revealed a significant impact on gut microbiome by dietary protein and carbohydrate ratio. The effect was more pronounced in OW cats than LN cats. While no microbial taxon was different between groups in LN cats, compositional changes occurred at different taxonomical ranks in OW cats. At the phylum level, Fusobacteria became more abundant in HPLC-fed cats than in CON-fed cats. At the genus level, five short-chain fatty acid (SCFA) producers had altered compositions in response to the diets: Faecalibacterium and Fusobacterium are more abundant in HPLC-fed cats while the abundances of Megasphaera, Bifidobacterium, and Veillonella increased in CON-fed cats. Predicted microbial gene networks showed changes in energy metabolism and one-carbon metabolism pathways. Our study demonstrated differential responses to HPLC diet between obese vs. lean cats and opportunities to explore these SCFA-producers for weight management in cats.

Alcohol consumption combined with dietary low-carbohydrate/high-protein intake increased the left ventricular systolic dysfunction risk and lethal ventricular arrhythmia susceptibility in apolipoprotein E/low-density lipoprotein receptor double-knockout mice.

Alcohol abuse is positively associated with cardiovascular disease. Dietary low-carbohydrate/high-protein (LCHP) intake confers a greater mortality risk. Here, the impact of ethanol consumption in combination with dietary LCHP intake on left ventricular (LV) systolic function and lethal ventricular arrhythmia susceptibility were investigated in apolipoprotein E/low-density lipoprotein receptor double-knockout (AL) mice. The underlying mechanisms, cardiac sympathovagal balance, beta-adrenergic receptor (ADRB) levels, and gap junction channel protein connexin 43 (Cx43) expression, were examined. Male AL mice fed an LCHP diet with or without ethanol were bred for 16 weeks. Age-matched male AL and wild-type mice received standard chow diet and served as controls. The following were used to assess LV systolic function, lethal ventricular arrhythmia susceptibility, cardiac sympathovagal balance, Cx43 expression, and ADRB levels: The results demonstrated that ethanol consumption in combination with dietary LCHP intake worsened LCHP-induced LV systolic dysfunction in AL mice and enhanced their susceptibility in the ventricular arrhythmia-evoked test. There were concomitant increases in LV weight, LF/HF ratio shown by HRV, TH, ADRB1, ADRB2, and Cx43 expressions by LV fluorescence immunohistochemistry, and LV Cx43 messenger ribonucleic acid expression by PCR. In AL mice, alcohol consumption combined with dietary LCHP intake may thus promote a shift in cardiac sympathovagal balance toward sympathetic predominance, the increases in beta-adrenergic receptors (ADRB1 and ADRB2), and then affect the gap junction channel protein Cx43, which in turn could contribute to increased risks of LV systolic dysfunction and susceptibility to lethal ventricular arrhythmia.

Low-protein/high-carbohydrate diet induces AMPK-dependent canonical and non-canonical thermogenesis in subcutaneous adipose tissue

Low-protein/high-carbohydrate (LPHC) diet has been suggested to promote metabolic health and longevity in adult humans and animal models. However, the complex molecular underpinnings of how LPHC diet leads to metabolic benefits remain elusive. Through a multi-layered approach, here we observed that LPHC diet promotes an energy-dissipating response consisting in the parallel recruitment of canonical and non-canonical (muscular) thermogenic systems in subcutaneous white adipose tissue (sWAT). In particular, we measured Ucp1 induction in association with up-regulation of actomyosin components and several Serca (Serca1, Serca2a, Serca2b) ATPases. In beige adipocytes, we observed that AMPK activation is responsible for transducing the amino acid lowering in an enhanced fat catabolism, which sustains both Ucp1-and Serca-dependent energy dissipation. Limiting AMPK activation counteracts the expression of brown fat and muscular genes, including Ucp1 and Serca, as well as mitochondrial oxidative genes. We observed that mitochondrial reactive oxygen species are the upstream molecules controlling AMPK-mediated metabolic rewiring in amino acid-restricted beige adipocytes. Our findings delineate a novel metabolic phenotype of responses to amino acid shortage, which recapitulates some of the benefits of cool temperature in sWAT. In conclusion, this highlights LPHC diet as a valuable and practicable strategy to prevent metabolic diseases through the enhancement of mitochondrial oxidative metabolism and the recruitment of different energy dissipating routes in beige adipocytes.

Exploring the Impact of a Low-Protein High-Carbohydrate Diet in Mature Broodstock of a Glucose-Intolerant Teleost, the Rainbow Trout.

Sustainable aquaculture production requires a greater reduction in the use of marine-derived ingredients, and one of the most promising solutions today is the augmentation in the proportion of digestible carbohydrates in aquafeed. This challenge is particularly difficult for high trophic level teleost fish as they are considered to be glucose-intolerant (growth delay and persistent postprandial hyperglycemia observed in juveniles fed a diet containing more than 20% of carbohydrates). It was previously suggested that broodstock could potentially use carbohydrates more efficiently than juveniles, probably due to important metabolic changes that occur during gametogenesis. To investigate this hypothesis, 2-year old male and female rainbow trout (Oncorhynchus mykiss) were either fed a diet containing no carbohydrates (NC) or a 35%-carbohydrate diet (HC) for an entire reproductive cycle. Zootechnical parameters as well as the activities of enzymes involved in carbohydrate metabolism were measured in livers and gonads. Fish were then reproduced to investigate the effects of such a diet on reproductive performance. Broodstock consumed the HC diet, and in contrast to what is commonly observed in juveniles, they were able to grow normally and they did not display postprandial hyperglycemia. The modulation of their hepatic metabolism, with an augmentation of the glycogenesis, the pentose phosphate pathway and a possible better regulation of gluconeogenesis, may explain their improved ability to use dietary carbohydrates. Although the HC diet did induce precocious maturation, the reproductive performance of fish was not affected, confirming that broodstock are able to reproduce when fed a low-protein high-carbohydrate diet. In conclusion, this exploratory work has shown that broodstock are able to use a diet containing digestible carbohydrates as high as 35% and can then grow and reproduce normally over an entire reproductive cycle for females and at least at the beginning of the cycle for males. These results are highly promising and suggest that dietary carbohydrates can at least partially replace proteins in broodstock aquafeed.

Cardio-metabolic consequences of dietary carbohydrates: reconciling contradictions using nutritional geometry.

Carbohydrates are the major source of dietary energy, but their role in health and disease remains controversial. Recent epidemiological evidence suggests that the increased consumption of carbohydrates is associated with obesity and increased risk of mortality and dietary trials show that carbohydrate restriction leads to weight loss and improved glycaemic status in obese and diabetic subjects. In contrast, the diets of populations with long and healthy lifespans (e.g. traditional Okinawans from Japan) are high in carbohydrate and low in protein, and several clinical and preclinical studies have linked low-carbohydrate-high-protein diets with increased mortality risk. In this paper we attempt to reconcile these contradictory findings by moving beyond traditional single-nutrient analyses to consider the interactions between nutrients on health outcomes. We do so using the Geometric Framework (GF), a nutritional modelling platform that explicitly considers the main and interactive effects of multiple nutrients on phenotypic characteristics. Analysis of human data by GF shows that weight loss and improved cardio-metabolic outcomes under carbohydrate restriction derive at least in part from reduced caloric intake due to the concomitantly increased proportion of protein in the diet. This is because, as in many animals, a specific appetite for protein is a major driver of food intake in humans. Conversely, dilution of protein in the diet leverages excess food intake through compensatory feeding for protein ('protein leverage'). When protein is diluted in the diet by readily digestible carbohydrates and fats, as is the case in modern ultra-processed foods, protein leverage results in excess calorie intake, leading to rising levels of obesity and metabolic disease. However, when protein is diluted in the diet by increased quantities of less readily digestible forms of carbohydrate and fibre, energy balance is maintained and health benefits accrue, especially during middle age and early late-life. We argue that other controversies in carbohydrate research can be resolved using the GF methodology in dietary studies.

Effects of Synbiotic Supplement on Human Gut Microbiota, Body Composition and Weight Loss in Obesity.

Targeting gut microbiota with synbiotics (probiotic supplements containing prebiotic components) is emerging as a promising intervention in the comprehensive nutritional approach to reducing obesity. Weight loss resulting from low-carbohydrate high-protein diets can be significant but has also been linked to potentially negative health effects due to increased bacterial fermentation of undigested protein within the colon and subsequent changes in gut microbiota composition. Correcting obesity-induced disruption of gut microbiota with synbiotics can be more effective than supplementation with probiotics alone because prebiotic components of synbiotics support the growth and survival of positive bacteria therein. The purpose of this placebo-controlled intervention clinical trial was to evaluate the effects of a synbiotic supplement on the composition, richness and diversity of gut microbiota and associations of microbial species with body composition parameters and biomarkers of obesity in human subjects participating in a weight loss program. The probiotic component of the synbiotic used in the study contained Lactobacillus acidophilus, Bifidobacterium lactis, Bifidobacterium longum, and Bifidobacterium bifidum and the prebiotic component was a galactooligosaccharide mixture. The results showed no statistically significant differences in body composition (body mass, BMI, body fat mass, body fat percentage, body lean mass, and bone mineral content) between the placebo and synbiotic groups at the end of the clinical trial (3-month intervention, 20 human subjects participating in weight loss intervention based on a low-carbohydrate, high-protein, reduced energy diet). Synbiotic supplementation increased the abundance of gut bacteria associated with positive health effects, especially Bifidobacterium and Lactobacillus, and it also appeared to increase the gut microbiota richness. A decreasing trend in the gut microbiota diversity in the placebo and synbiotic groups was observed at the end of trial, which may imply the effect of the high-protein low-carbohydrate diet used in the weight loss program. Regression analysis performed to correlate abundance of species following supplementation with body composition parameters and biomarkers of obesity found an association between a decrease over time in blood glucose and an increase in Lactobacillus abundance, particularly in the synbiotic group. However, the decrease over time in body mass, BMI, waist circumstance, and body fat mass was associated with a decrease in Bifidobacterium abundance. The results obtained support the conclusion that synbiotic supplement used in this clinical trial modulates human gut microbiota by increasing abundance of potentially beneficial microbial species.

The Effect of Low-Calorie High Protein Diet on Insulin, TNF- α and P38MAPK Levels in Insulin-Resistant PCOS Mice Models

Introduction: Polycystic Ovary Syndrome (PCOS) is found in 33% -38% of women who are overweight. The characteristic correlation of PCOS with insulin resistance, hyperandrogenemia and chronic inflammation such as tumor necrosis factor-α (TNF-α) involves activity of the mitogen protein signaling pathway (MAPK). Calorie restriction or a low carbohydrate diet for women with PCOS is beneficial for their hormonal and metabolic profile. Objective: The purpose of this study is to determine the effect of low carbohydrate high protein diet (LCHP) in reducing insulin levels, TNF-α levels and p38MAPK expression. Methods: This study used PCOS mice models which were divided into three groups: K- (untreated mice given standard feed), K+ (PCOS-IR mice model given standard feed) and P (PCOS mice model given the LCHP diet) for 20 days. The PCOS mice model was obtained from the injection of testosterone propionate for 28 days. Insulin and TNF-α levels of the blood serum were measured using ELISA and p38MAPK examination was done using immunohistochemicals on ovarian tissue. Results: Results showed that there was a significant difference of insulin and TNF-α levels between the group given the LCHP diet and the other groups (p 0.05). Conclusion: The findings in this study could potentially be due to the activity of the MAPK pathway caused by oxidative stress in cells that effects p38MAPK activity, in which it is still unclear whether oxidative stress causes the occurrence of kinase activation or not. However, it has no effect on insulin signaling pathways and the proinflammatory cytokine TNF-α.

Influence of macronutrient composition of commercial diets on circulating leptin and adiponectin concentrations in overweight dogs.

Leptin and adiponectin play important roles in obesity‐related inflammation and comorbidities. Previous research suggests that alterations in dietary macronutrient composition can modify circulating leptin and adiponectin concentrations in people, but limited research on this subject has been performed in dogs. This study investigated the effects of commercial high protein (HP), high fat (HF) and high carbohydrate medium protein (HCMP) diets on baseline (T−1) concentrations, post‐prandial peak concentrations and total release in a ten‐hour time span of leptin and adiponectin in dogs, when compared to a maintenance high carbohydrate low protein (HCLP) diet. Thirty‐six overweight dogs were fed the HCLP diet in a one‐week control period, after which the animals were assigned to one of three groups. In three four‐week periods, each group was fed all test diets in a different sequence. At the last day of each period, blood was sampled at one hour before feeding (T−1) and at three (T3), six (T6) and nine (T9) hours after feeding. Feeding caused peak leptin concentrations at T6 and T9 (p < .001). No significant post‐prandial change in adiponectin concentrations was found (p = .056). The HP diet resulted in lower leptin peak concentrations (p = .004) and AUCT−1–T9 (p = .01), but none of the diets influenced baseline leptin concentrations (p = .273). Baseline adiponectin concentrations were lower for the HF diet (p = .018) and HCMP (p < .001), and the HP, HF and HCMP AUCT−1–T9 (p < .001) were lower compared with the HCLP diet. Female dogs had lower adiponectin baseline concentrations (p = .041) and AUCT−1–T9 (p = .023) than male dogs. In conclusion, the HP diet was associated with the lowest post‐prandial peak leptin concentration and the least decrease in adiponectin release, suggesting that a HP diet may improve immune‐metabolic health and post‐prandial satiety in overweight dogs.

Impact of Weight Loss Strategies on Obesity-Induced DNA Damage.

ScopeObesity causes DNA damage, which is causally related to several disorders including cancer, infertility, and cognitive dysfunctions. The aim of this study is to investigate whether weight loss improves the integrity of the genetic material.Methods and ResultsOverweight mice are fed ad libitum either with a Western diet (WD), with a 40% caloric restricted WD, or with a high carbohydrate low protein (HCLP) diet. Caloric restriction and also the HCLP diet lead to ca. 30% weight loss, which is paralleled by decreased DNA damage (“comet” formation) and oxidative damage of purines in inner organs, additionally the activity of nucleotide excision repair increased. The effects are more pronounced in animals that have received the HCLP chow. Results of biochemical analyses indicate that the reduction of DNA damage is associated with a decrease of pro‐inflammatory cytokines and lower insulin levels.ConclusionThe study indicates that weight loss may prevent obesity‐associated adverse health effects due to reduction of overall DNA damage.

The Gut Microbiome on a Periodized Low-Protein Diet Is Associated With Improved Metabolic Health.

A periodized (14 days on/14 days off) 5% low protein-high carbohydrate (pLPHC) diet protects against weight gain, improves glucose tolerance in mice and interacts with concurrent voluntary activity wheel training on several parameters including weight maintenance and liver FGF21 secretion. The gut microbiome (GM) responds to both diet and exercise and may influence host metabolism. This study compared the cecal GM after a 13.5-week intervention study in mice on a variety of dietary interventions ± concurrent voluntary exercise training in activity wheels. The diets included chronic chow diet, LPHC diet, 40 E% high protein-low carbohydrate (HPLC) diet, an obesigenic chronic high-fat diet (HFD) and the pLPHC diet. Our hypothesis was that the GM changes with pLPHC diet would generally reflect the improved metabolic health of the host and interact with concurrent exercise training. The GM analyses revealed greater abundance phylum Bacteroidetes and the genus Akkermansia on chronic and periodized LPHC and higher abundance of Oscillospira and Oscillibacter on HFD. The differences in diet-induced GM correlated strongly with the differences in a range of host metabolic health-measures. In contrast, no significant effect of concurrent exercise training was observed. In conclusion, pLPHC diet elicits substantial changes in the GM. In contrast, only subtle and non-significant effects of concurrent activity wheel exercise were observed. The pLPHC-associated microbiome may contribute to the healthier host phenotype observed in these mice.

Changes in amino acid profiles and liver alterations in pregnant rats with a high carbohydrate/low protein diet

Introduction and aimIntake of a high-carbohydrate, low-protein diet (HCD/LPD) during pregnancy promotes metabolic disturbances. It has been suggested that liver function during pregnancy contributes to the synthesis of proteins necessary for fetal development during this stage. The liver is a site of response to the synthesis of macronutrients such as proteins. However, it is unknown how HCD/LPD is associated with modifications to the amino acid profiles and hepatic alterations in the maternal environment during pregnancy. Materials and methodsA transverse longitudinal study was done in primiparous mothers during gestation (G) (G1 day 1, G5 day 5, G15 day 15, and G20 day 20). Histological analysis was used to assess hepatic alterations, and amino acid profiles in the liver were analyzed with high performance liquid chromatography (HPLC). Food and water intake was quantified, and peripheral biochemical indicators in serum were measured. ResultsMothers with HCD/LPD had increased micro and macro vesicles of fat, necrosis, and inflammation in the liver on G5. The total concentration of hepatic amino acids increased by 40% on G1, 17% on G5, and 25% on G15; and, there was a 12% decrease on G20. The following increases were observed in the liver on G1: arginine 68%, histidine 75%, alanine 18%, methionine 71%, and phenylalanine 51% (p>0.05); on G5: arginine 12%, methionine 34%, and phenylalanine 83% (p>0.05); on G15: arginine and phenylalanine 66%, tryptophan 81% and histidine 60.4% (p>0.05); and on G20: arginine 32% (p>0.05). No weight loss, changes in food consumption, or hepatomegaly occurred. ConclusionsHCD/LPD during pregnancy in primiparous mothers may promote development of fat vesicles. Possibly, this condition causes metabolic adaptations and nitrogen management reflected in decreased levels of serum urea and altered amino acid profiles in the liver.

Low-carbohydrate high-protein diet diminishes the insulin response to glucose load via suppression of SGLT-1 in mice

The purpose of this study was to examine the effects of a low-carbohydrate high-protein (LCHP) diet on the expression of glucose transporters and their relationships to glucose metabolism. Male C57BL/6 mice were fed a normal control or LCHP diet for 2weeks. An oral glucose tolerance test and insulin tolerance test (ITT) were performed, and the expression of glucose transporters was determined in the gastrocnemius muscle, jejunum and pancreas. The increase in plasma insulin concentrations after glucose administration was reduced in the LCHP group. However, LCHP diet had no effects on peripheral insulin sensitivity or glucose transporters expression in the gastrocnemius and pancreas. Soluble glucose transporter (SGLT)-1 protein content in jejunum was lower in the LCHP group. Taken together, these results suggest that the blunted insulin response after glucose administration in LCHP diet-fed mice might be due to decreased SGLT-1 expression, but not to an increase in peripheral insulin sensitivity. Abbreviations: LCHP: low-carbohydrate high-protein; ITT: insulin tolerance test; GLUT: glucose transporter; SGLT: soluble glucose transporter; OGTT: oral glucose tolerance test; AUC: area under the curve.