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The question of whether the ratio of dietary carbohydrates to fat substantially impacts total energy expenditure (TEE) or body fat has been investigated for decades, with most studies pointing to no clinically meaningful effect. However, a recent study by Ebbeling et al. (https://doi.org/10.1136/bmj.k4583) reported substantial differences in TEE between diets varying in their ratio of carbohydrate to fat. The original pre-registered statistical analysis plan for the primary study outcome of Ebbeling et al. addressed the question of whether the reduction in TEE during weight loss maintenance compared to the pre-weight loss baseline depended on the dietary carbohydrate to fat ratio. However, the final analysis plan was modified to make the diet comparisons with the TEE measurements collected in the immediate post-weight loss period rather than at the pre-weight loss baseline. Here, we reanalyzed the data according to the original plan we found that the TEE differences were no longer statistically significant between the diet groups and the nominal diet differences of ~100 kcal/d were much smaller than the ~250 kcal/d differences reported in the publication. In other words, when conducting the analysis originally planned by the authors we found that the significant increases in TEE with the low carbohydrate diet that were reported by Ebbeling et al. disappeared. Furthermore, the TEE effect modification by baseline insulin secretion also disappeared.

Introduction: When dietary carbohydrate replaces fat, HDL-C and apoA1 decrease. The proportion in plasma of large HDL2 decreases while small HDL3 increases. These findings suggest that diet affects metabolically important attributes of HDL that produce the size changes. We studied in humans the effect of dietary carbohydrate and unsaturated fat on the HDL proteome and metabolism of 9 HDL proteins across 6 HDL sizes. Methods and Results: Twelve participants were placed on a controlled high unsaturated fat (HF) or high carbohydrate (HC) diet in a randomized crossover design. At the end of each 4-week diet period, subjects were infused with D3-Leu tracer, and blood was collected for 70 hrs. ApoA1-HDL was prepared by immunoaffinity purification, separated into 6 sizes α0, α1, α2, α3, preβ, and Conclusions: Dietary carbohydrate when it replaces unsaturated fat alters the HDL proteome and metabolism of several HDL proteins on specific HDL sizes. Carbohydrate increases the abundance of proteins involved in lipid metabolism and the acute phase response, decreases antioxidant and protease inhibitor proteins, and enhances turnover of apoE and apoA1. This study suggests that diet modulates HDL function by affecting HDL composition and the metabolism of major HDL proteins.

Introduction: While much has been published on the effect of different amounts of dietary carbohydrate (carb) on cardiovascular disease (CVD) risk, data on effects of different types of carb (simple, refined and unrefined) are limited. Objective: To determine the relative comparability for an isocaloric replacement of unrefined-carb (UC; e.g., brown rice and bread/pasta made from whole wheat flour), refined-carb (RC; e.g., white rice and bread/pasta made from white flour) and simple-carb (SC; e.g., sucrose and high fructose corn syrup) on serum lipid and lipoprotein profile, adipose tissue gene expression of macrophage and inflammation markers, cytokine secretion and adipocyte size, and cholesterol efflux in peripheral blood mononuclear cells (PBMC). Methods: Study subjects (men and postmenopausal women [N=11], 65±8 y, BMI 29.8±3.2 kg/m 2 , LDL-C ≥2.6 mmol/L) were provided with isocaloric diets (60% E total carb, 15% E protein, 25% E fat) enriched in SC, RC or UC for 4.5 weeks, with a 2-week washout period between diet phases, using a randomized, cross-over design. Body weight was maintained within +/- 2 kg. At the end of each diet phase serum lipid and lipoprotein profile was determined using standard methods. Abdominal subcutaneous adipose tissue biopsies were collected and used to assess gene expression of macrophage and inflammation markers, cytokine secretion, and cell size. PBMCs were isolated and cultured to assess cholesterol efflux. Results: Fasting serum TC (p=0.004) and LDL-C (p=0.002) concentrations were higher after subjects consumed the RC diet than after the SC and UC diet phases. No significant differences were observed among diets in serum HDL-C (p=0.32), VLDL-C (p=0.17), TG (p=0.19), and NEFA (p=0.99) concentrations. Adipocyte size was largest after subjects consumed the RC diet and smallest after the SC diet (p Conclusions: Consuming the RC diet resulted in higher serum TC and LDL-C concentrations, and concurrently increased abdominal subcutaneous adipocyte size. Dietary carb type had no significant effect on markers of macrophage infiltration, inflammation or cytokine secretion in adipose tissue, or macrophage cholesterol efflux. Results from this study provide mechanistic support for the epidemiologic findings that increasing consumption of RC diet is positively associated with CVD risk.

A common-garden experiment was carried out to compare two genetically distinct strains of Atlantic salmon (Salmo salar) fed diets with either high (CHO) or low (NoCHO) digestible carbohydrate (starch). Twenty salmon from either a commercial farmed strain (F) or a land-locked population (G) were placed in two tanks (10 fish of each population in each tank) and fed either CHO or NoCHO feeds. At the end of the experiment fish were fasted for 8 h, euthanized and blood and liver collected. Both diet and population had an effect on circulating glucose levels with G showing hypoglycaemia and dietary starch increasing this parameter. In contrast, G showed increased plasma triacylglycerol levels regardless of dietary treatment suggesting faster conversion of glucose to triacylglycerol. This different ability to metabolize dietary starch among strains was also reflected at a molecular (gene) level as most of the metabolic pathways evaluated were mainly affected by the factor population rather than by diet. The data are promising and suggest different regulatory capacities toward starch utilization between land-locked salmon and the farmed stock. Further analyses are necessary in order to fully characterize the capacity of land-locked salmon to utilize dietary carbohydrate. © 2018 Betancor, Olsen, Marandel, Skulstad, Madaro, Tocher and Panserat. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

In experiment 1, juvenile sea urchins (n = 80, 0.088 ± 0.001 g wet weight and 5.72 ± 0.04 mm diameter) were held individually and fed ad libitum one of three semi-purified formulated diets (n = 16 individuals treatment-1). In the diets, protein was held constant (310g kg-1 dry, as fed) and carbohydrate level varied (190, 260, or 380 g kg-1 dry, as fed). Wet weights were measured every 2 weeks. Total wet weight gain was inversely proportional to dietary carbohydrate level and energy content of the respective diet. In experiment 2, sea urchins (5.60 ± 0.48g wet weight, n= 40) fed 190 g kg-1 carbohydrate consumed significantly more dry feed than those fed 260 g kg-1, but not more than those fed 380 g kg-1 carbohydrate. Based on differential feed intake rates, sea urchins that consumed more feed also consumed higher levels of protein and had the highest weight gain. Consequently, protein content and/or protein: energy ratio may be important in determining feed utilization and growth among sea urchins in this study. The average digestible energy intake was approximately 70 kcal kg-1 body weight day-1, suggesting daily caloric intake of juvenile Lytechinus variegatus is lower than in shrimp and fish.

Molecular dynamics (MD) simulation is an emerging technique in studying the interactions between macromolecules with small ligands in different media. In this review, the application of MD simulation in food carbohydrate research, including carbohydrate hydration, carbohydrate interaction with other components and carbohydrate inclusion complexation, will be discussed. The advantages and disadvantages of MD simulation in food carbohydrate research and trends will be proposed. The frequently used software to run the MD simulation and a standard protocol for MD simulation procedures have been discussed. This review offers a general idea about how to use MD simulation in food carbohydrate research, and what could be expected from such research. Industrial relevance This review offers a general idea about how to use MD simulation in food carbohydrate research, and what could be expected from such research. This review might be useful for the flavor and nutraceuticals encapsulation, dietary carbohydrate and modified starch industries.

Background and aims The positive and negative health effects of dietary carbohydrates are of interest to both researchers and consumers. Methods International experts on carbohydrate research held a scientific summit in Stresa, Italy, in June 2013 to discuss controversies surrounding the utility of the glycemic index (GI), glycemic load (GL) and glycemic response (GR). Results The outcome was a scientific consensus statement which recognized the importance of postprandial glycemia in overall health, and the GI as a valid and reproducible method of classifying carbohydrate foods for this purpose. There was consensus that diets low in GI and GL were relevant to the prevention and management of diabetes and coronary heart disease, and probably obesity. Moderate to weak associations were observed for selected cancers. The group affirmed that diets low in GI and GL should always be considered in the context of diets otherwise understood as healthy, complementing additional ways of characterizing carbohydrate foods, such as fiber and whole grain content. Diets of low GI and GL were considered particularly important in individuals with insulin resistance. Conclusions Given the high prevalence of diabetes and pre-diabetes worldwide and the consistency of the scientific evidence reviewed, the expert panel confirmed an urgent need to communicate information on GI and GL to the general public and health professionals, through channels such as national dietary guidelines, food composition tables and food labels.

Dietary shifts can drive molecular evolution in mammals and a major transition in human history, the agricultural revolution, favored carbohydrate consumption. We investigated the evolutionary history of nine genes encoding brush-border proteins involved in carbohydrate digestion/absorption. Results indicated widespread adaptive evolution in mammals, with several branches experiencing episodic selection, particularly strong in bats. Many positively selected sites map to functional protein regions (e.g., within glucosidase catalytic crevices), with parallel evolution at SI (sucrase-isomaltase) and MGAM (maltase-glucoamylase). In human populations, five genes were targeted by positive selection acting on noncoding variants within regulatory elements. Analysis of ancient DNA samples indicated that most derived alleles were already present in the Paleolithic. Positively selected variants at SLC2A5 (fructose transporter) were an exception and possibly spread following the domestication of specific fruit crops. We conclude that agriculture determined no major selective event at carbohydrate metabolism genes in humans, with implications for susceptibility to metabolic disorders.

Nos ultimos anos a chia ( Salvia hispanica L .) vem se tornando cada vez mais presente na dieta dos brasileiros e despertando o interesse de muitos pesquisadores, pelas suas propriedades funcionais e seus respectivos beneficios a saude. O objetivo desse trabalho foi desenvolver massas alimenticias com diferentes percentuais de farinha de chia em substituicao a farinha de trigo e avaliar o impacto da chia nas caracteristicas nutricionais, tecnologicas e sensoriais. As massas foram desenvolvidas pela substituicao de 7,5% (T1), 15% (T2) e 30% (T3) da farinha de trigo por farinha de chia em relacao a formulacao controle (C). Avaliou-se a qualidade das massas por meio de testes de cozimento (aumento de peso e de volume, tempo de cozimento e perda de solidos na agua de cozimento), composicao quimica (umidade, lipidios, fibras, proteina, cinzas e carboidratos) cor, pelo colorimetro Minolta e analise sensorial atraves de teste de aceitacao. As massas formuladas com farinha de chia apresentaram maior valor nutricional e caracteristicas tecnologicas superiores a controle. Os resultados da analise sensorial demonstraram que a massa com 7,5% de farinha de chia obteve maior aceitabilidade no sabor e a massa controle na cor e textura.

IBS is one of the most common types of functional bowel disorder. Increasing attention has been paid to the causative role of food in IBS. Food ingestion precipitates or exacerbates symptoms, such as abdominal pain and bloating in patients with IBS through different hypothesised mechanisms including immune and mast cell activation, mechanoreceptor stimulation and chemosensory activation. Wheat is regarded as one of the most relevant IBS triggers, although which component(s) of this cereal is/are involved remain(s) unknown. Gluten, other wheat proteins, for example, amylase-trypsin inhibitors, and fructans (the latter belonging to fermentable oligo-di-mono-saccharides and polyols (FODMAPs)), have been identified as possible factors for symptom generation/exacerbation. This uncertainty on the true culprit(s) opened a scenario of semantic definitions favoured by the discordant results of double-blind placebo-controlled trials, which have generated various terms ranging from non-coeliac gluten sensitivity to the broader one of non-coeliac wheat or wheat protein sensitivity or, even, FODMAP sensitivity. The role of FODMAPs in eliciting the clinical picture of IBS goes further since these short-chain carbohydrates are found in many other dietary components, including vegetables and fruits. In this review, we assessed current literature in order to unravel whether gluten/wheat/FODMAP sensitivity represent 'facts' and not 'fiction' in IBS symptoms. This knowledge is expected to promote standardisation in dietary strategies (gluten/wheat-free and low FODMAP) as effective measures for the management of IBS symptoms.

BACKGROUND/OBJECTIVES: The relationship between food intake and nutritional status has been clearly established. Yet, there are only limited studies on food intake among family members and their nutritional status. The study examined the relationship between intra-household food distribution and coexistence of dual forms of malnutrition (DFM) in the same household. SUBJECTS/METHODS: Households with a malnourished child and overweight mother were categorized as DFM. Intra-household food distribution among family members was reported using ratios, which are a measure of individual intakes as compared to all household member intakes adjusted to RDA. RESULTS: A1,899 families were included in the study. The prevalence of DFM was 29.8% (95%CI 26.5-31.2). Children consumed lower amounts of energy (OR 1.34; 95%CI 1.06-1.69, P = 0.011), carbohydrates (OR 1.2; 95%CI1.03-1.61, P = 0.022), protein (OR 1.3; 95%CI 1.03-1.64, P = 0.026), and fat (OR 1.3; 95%CI 1.05-1.66, P = 0.016) than their mothers and other family members. In contrast, mothers consumed more carbohydrates than children and other family members (OR1.24; 95%CI 1.02-1.51, P = 0.03). CONCLUSIONS: This study is the first to report on the food distribution among family members and its relationship with occurrence of DFM in Indonesia. The results confirm the occurrence of an unequal food distribution between children and mothers, which increases risk of DFM in the household. The results also demonstrate that nutritional education at the household level is important to increase awareness of the impact of DFM. Nutrition Research and Practice 2015;9(2):174-179; doi:10.4162/nrp.2015.9.2.174; pISSN 1976-1457 eISSN 2005-6168

A comparative feeding trial was undertaken to evaluate the relative use of dietary carbohydrate, non-essential amino acids (NEAA), and lipids for energy by hybrid striped bass Morone chrysops ♀ × M. saxatilis ♂. The control diet was formulated to contain 40% crude protein, 25% dextrinized corn starch as available carbohydrate (CHO) and 10% lipid. In the three experimental diets, the 25% dextrinized starch was replaced with either, 25% NEAA (12.5% l -glutamate and 12.5% l -aspartate), an additional 11% lipid (21% total lipid; designated high-lipid diet), or 0% CHO with protein and lipid components concentrated to 53.3% and 13.3%, respectively, and each diet was fed to juvenile fish such that all groups received equal amounts of intact protein. Juvenile hybrid striped bass (average initial weight of 21.1 g/fish) were stocked as groups of 12 fish in 110-L aquaria containing fresh water and operated as a recirculating system. Fish in triplicate aquaria were fed each dietary treatment at a rate approaching apparent satiation for 6 weeks. Fish fed the control diet with 25% CHO or high-lipid diet had significantly ( P

Consuming dietary fibre confers a number of large bowel health benefits through various interacting mechanisms. Here we describe and mathematically model how these key mechanisms respond to changes in the concentration of fibre consumed. The key markers of bowel health and function, short chain fatty acid (SCFA) and branched chain fatty acid (BCFA) concentrations, faecal bulk, transit time and pH are interrelated and captured in a model with just four parameters. The model was parameterised using animal (rat) data from the literature for faecal bulking, BCFA production, SCFA production and increasing acidity by the gut microbiota. Surprisingly, the model replicated the data in the absence of explicit representation of both the microbiota and their interactions with mucins. Interestingly, the model identified that there was an optimal fibre concentration at which SCFA was maximised, and further increases in fibre actually caused SCFA to decline. Extrapolating beyond the range of fibre content in the dataset predicted interesting results in terms of very short transit times for digesta and high faecal bulk, suggesting the need for new experiments to verify the range of fibre concentrations for which the model is valid. The parameterised and validated model may have value as a tool for predicting the potential health benefits arising from consuming varying fibre concentrations.

Nutrition therapy is considered a key component of diabetes management, yet evidence around the ideal macronutrient composition of the diet remains inconclusive. A systematic review and meta-analysis was performed to assess the effects of carbohydrate-restricted diets (≤45% of total energy) compared to high carbohydrate diets (>45% of total energy) on glycemic control in adults with diabetes mellitus. Six databases were searched for articles published between January 1980 and August 2016. Primary outcome was between-group difference in HbA1c change. Individual effect sizes were standardized, and a meta-analysis performed to calculate pooled effect size using random effects. 25 RCTs involving 2412 participants were included. Carbohydrate-restricted diets, in particular those that restrict carbohydrate to

US organic poultry producers are under pressure to find feed alternatives to corn and wheat. Hulless oats offer advantages such as wide geographic adaptation of the plant and high concentrations of protein and oil in the grain. They have shown considerable potential in experimental work as a feed grain for poultry, but more research is needed into their influence on the sensory and nutritional properties of eggs. In this study, hulless oats were substituted for corn or wheat at 200 g kg−1 in diets fed to Hy-Line Brown hens and eggs were sampled for sensory evaluation after 8 weeks. Discrimination tests of blended and baked egg samples found evidence of difference between eggs from oat-based diets and those from the oat-free control (p < 0.05 for eggs from an oat-corn diet, p < 0.01 for eggs from an oat-wheat diet). Acceptance tests of similar samples showed that eggs from the oat-wheat diet were significantly less liked than control eggs for their texture (p < 0.01) and response to cooking (p < 0.01), while eggs from the oat-corn diet were somewhat less liked. Yolk weight was greater (p < 0.05) in control eggs (34.1 g) than eggs from oat-corn (31.6 g) or oat-wheat (31.2 g) diets, leading to smaller yolk proportion in the oat-fed eggs. Fatty acid profile differences across treatments were not of nutritional significance, and no evidence was found that the feeding of hulless oats improved storage properties of eggs. In this study, modifying the carbohydrate source in layer diets was shown to change textural properties of cooked eggs in a way that was perceptible to untrained consumers, probably by reducing the yolk proportion. This finding was not commercially relevant owing to small effect size, and results overall add to existing evidence that hulless oats can be fed to poultry at a moderate proportion of the diet with no negative effect on consumer acceptability of eggs. Regardless of the small effect size, however, findings are interesting from the food chemistry perspective because they provide novel evidence of how the thermal properties of eggs can be altered by a change in hen dietary carbohydrate source.

RESUMO Os quatis são mamíferos carnívoros da família Procyonidae, são animais onívoros, encontrados nas Américas do Norte, Central e Sul, sendo amplamente distribuídos no Brasil. O objetivo deste trabalho é analisar as alterações nos parâmetros sanguíneos de duas diferentes populações de quatis (Nasua nasua), da região oeste do Paraná, e avaliar a qualidade de vida e a interferência antrópica nos hábitos alimentares desses animais. A análise sorológica foi realizada em duas diferentes populações de quatis (Nasua nasua) que habitam duas unidades de conservação em regiões distintas no município de Foz do Iguaçu. Em uma das populações, foram visualizados cerca de cinquenta indivíduos, os quais se revelam em exposição direta aos seres humanos, e outra população menor, em torno de trinta indivíduos, os quais não possuem exposição direta aos seres humanos, o que, por sua vez, revelou importantes indicativos da qualidade de vida e de saúde desses animais. Foram realizadas avaliações bioquímicas do soro sanguíneo de 10 quatis adultos; cinco animais do grupo 1, população exposta aos seres humanos, e cinco animais do grupo 2, população com menor exposição. Com os resultados obtidos, foram feitas as comparações dos valores bioquímicos entre os grupos e com os valores de referência pesquisados na literatura. Os exames bioquímicos revelaram alterações significativas nos níveis de glicose e proteínas totais e alterações no nível plasmático de triglicerídeos nos quatis capturados na população em contado direto com seres humanos. Conclui-se que a saúde dos animais que possuem exposição direta com seres humanos está sendo afetada pelo consumo de uma dieta rica em carboidratos e gorduras, oriunda de alimentos industrializados fornecidos pelos turistas. ABSTRACT The coatis, carnivorous mammals of the Procyonidae family, are omnivorous animals, found in North, Central and South America and are widely distributed in Brazil. The objective of this study was to analyze changes in blood parameters in two different populations of coatis (Nasua nasua), of the western region of Paraná, and to evaluate the quality of life and the human interference in eating habits of these animals. Serologic analysis was performed in two different populations of coatis (Nasua nasua) inhabiting two conservation units in different areas in the city of Foz do Iguaçu. In one population, approximately fifty individuals were visualized, revealing themselves in direct exposure to humans as well as another minor population of about thirty individuals, which have no direct exposure to humans, which revealed important indicatives of the quality of life and health of these animals. Biochemical assessments of ten adults coatis serum were perfomred, five animals in group 1, population exposed to humans and five animals of the group 2, population less exposed. With the obtained results, comparisons were made between the groups’ biochemical values and the reference values found in the literature. Biochemical tests revealed significant changes in glucose levels and total protein and changes in plasma levels of triglycerides in coatis captured in the population in direct contact with humans. It follows that the health of animals that have direct exposure to humans is being affected by the consumption of a diet high in carbohydrates and fats, coming from processed foods provided by tourists.

Objectives The preferred countermeasure to avoid exercise-related hypoglycemia was investigated in a group of patients with type 1 diabetes participating in a stressful event, a 24×1-hour relay marathon. The carbohydrates actually consumed were compared to those estimated for each patient by applying a customizable algorithm, Exercise Carbohydrates Requirement Estimating Software (ECRES), based on patient's usual therapy and diet and on the exercise characteristics. Methods Glycemia was tested at the start, middle and end of the races. Usual therapies and diets and the adopted countermeasures were recorded in detail. Results We studied 19 patients who walked/ran 10.4±2.8 km with a heart rate of 167±11 beats per minute. Of the 19 patients, 7 patients reduced the administered insulin (premeal bolus or basal infusion rate). Glycemia fell by the end of the races (p=0.006; median −1.8 mmol⋅L −1 ; interquartile range −0.4 mmol⋅L −1 to −5.3 mmol⋅L −1 ), despite 9 patients being hyperglycemic at the start. Of the patients, 14 concluded the race with glycemia on target, and 4 patients were hyperglycemic. Amounts of carbohydrates actually consumed (median 30 g; interquartile range 0 g to 71 g) were not significantly different from those estimated by ECRES (median 38 g; interquartile range 24 g to 68 g), the 2 quantities being significantly related (R=0.64; p=0.003). ECRES estimated lower carbohydrate levels (−13 g) than the amounts actually consumed by the 4 patients who concluded their exercises with hyperglycemia. Conclusions Patients preferred to consume extra carbohydrates to avoid the possible exercise-induced hypoglycemia. ECRES would provide satisfactory estimates of the carbohydrate requirements, even for a stressful condition, and almost equal to the quantities consumed following medical advice.

Background Gene-diet interactions have been reported to contribute to the development of type 2 diabetes (T2D). However, to our knowledge, few examples have been consistently replicated to date. Objective We aimed to identify existing evidence for genemacronutrient interactions and T2D and to examine the reported interactions in a large-scale study. Design We systematically reviewed studies reporting genemacronutrient interactions and T2D. We searched the MEDLINE, Human Genome Epidemiology Network, and WHO International Clinical Trials Registry Platform electronic databases to identify studies published up to October 2015. Eligibility criteria included assessment of macronutrient quantity (e.g., total carbohydrate) or indicators of quality (e.g., dietary fiber) by use of self-report or objective biomarkers of intake. Interactions identified in the review were subsequently examined in the EPIC (European Prospective Investigation into Cancer)-InterAct case-cohort study (n = 21,148, with 9403 T2D cases; 8 European countries). Prentice-weighted Cox regression was used to estimate countryspecific HRs, 95% CIs, and P-interaction values, which were then pooled by random-effects meta-analysis. A primary model was fitted by using the same covariates as reported in the published studies, and a second model adjusted for additional covariates and estimated the effects of isocaloric macronutrient substitution. Results Thirteen observational studies met the eligibility criteria (n , 1700 cases). Eight unique interactions were reported to be significant between macronutrients [carbohydrate, fat, saturated fat, dietary fiber, and glycemic load derived from self-report of dietary intake and circulating n–3 (v-3) polyunsaturated fatty acids] and genetic variants in or near transcription factor 7–like 2 (TCF7L2), gastric inhibitory polypeptide receptor (GIPR), caveolin 2 (CAV2), and peptidase D (PEPD) (P-interaction , 0.05). We found no evidence of interaction when we tried to replicate previously reported interactions. In addition, no interactions were detected in models with additional covariates. Conclusions Eight gene-macronutrient interactions were identified for the risk of T2D from the literature. These interactions were not replicated in the EPIC-InterAct study, which mirrored the analyses undertaken in the original reports. Our findings highlight the importance of independent replication of reported interactions.

A key element contributing to deteriorating exercise capacity during physically demanding sport appears to be reduced carbohydrate availability coupled with an inability to effectively utilize alternative lipid fuel sources. Paradoxically, cognitive and physical decline associated with glycogen depletion occurs in the presence of an over-abundance of fuel stored as body fat that the athlete is apparently unable to access effectively. Current fuelling tactics that emphasize high-carbohydrate intakes before and during exercise inhibit fat utilization. The most efficient approach to accelerate the body's ability to oxidize fat is to lower dietary carbohydrate intake to a level that results in nutritional ketosis (i.e., circulating ketone levels >0.5 mmol/L) while increasing fat intake for a period of several weeks. The coordinated set of metabolic adaptations that ensures proper interorgan fuel supply in the face of low-carbohydrate availability is referred to as keto-adaptation. Beyond simply providing a stable source of fuel for the brain, the major circulating ketone body, beta-hydroxybutyrate, has recently been shown to act as a signalling molecule capable of altering gene expression, eliciting complementary effects of keto-adaptation that could extend human physical and mental performance beyond current expectation. In this paper, we review these new findings and propose that the shift to fatty acids and ketones as primary fuels when dietary carbohydrate is restricted could be of benefit for some athletes.

Open-water swimming (OWS) is a rapidly developing discipline. Events of 5–25 km are featured at FINA World Championships, and the international circuit includes races of 5–88 km. The Olympic OWS event, introduced in 2008, is contested over 10 km. Differing venues present changing environmental conditions, including water and ambient temperatures, humidity, solar radiation, and unpredictable tides. Furthermore, the duration of most OWS events (1–6 hr) creates unique physiological challenges to thermoregulation, hydration status, and muscle fuel stores. Current nutrition recommendations for open-water training and competition are either an extension of recommendations from pool swimming or are extrapolated from other athletic populations with similar physiological requirements. Competition nutrition should focus on optimizing prerace hydration and glycogen stores. Although swimmers should rely on self-supplied fuel and fluid sources for shorter events, for races of 10 km or greater, fluid and fuel replacement can occur from feeding pontoons when tactically appropriate. Over the longer races, feeding pontoons should be used to achieve desirable targets of up to 90 g/hr of carbohydrates from multitransportable sources. Exposure to variable water and ambient temperatures will play a significant role in determining race nutrition strategies. For example, in extreme environments, thermoregulation may be assisted by manipulating the temperature of the ingested fluids. Swimmers are encouraged to work with nutrition experts to develop effective and efficient strategies that enhance performance through appropriate in-competition nutrition.

A wide variety of natural sources are under investigation to evaluate their possible use for new functional ingredient formulation. Some records attested the traditional and ancient use of wild harvested microalgae as human food but their cultivation for different purposes started about 40 years ago. The most popular species are Arthrospira (traditional name, Spirulina), Chlorella spp., Dunaliella spp. and Haematococcus spp. Microalgae provide a bewildering array of opportunities to develop healthier food products using innovative approaches and a number of different strategies. Compared to other natural sources of bioactive ingredients, microalgae have many advantages such as their huge biodiversity, the possibility to grow in arid land and with limited fresh water consumption and the flexibility of their metabolism, which could be adapted to produce specific molecules. All these factors led to very sustainable production making microalgae eligible as one of the most promising foods for the future, particularly as source of proteins, lipids and phytochemicals. In this work, a revision of the knowledge about the use of microalgae as food and as a source of functional ingredients has been performed. The most interesting results in the field are presented and commented upon, focusing on the different species of microalgae and the activity of the nutritionally relevant compounds. A summary of the health effects obtained together with pros and cons in the adoption of this natural source as functional food ingredients is also proposed. © the Partner Organisations 2014.

Despite the potential relationship with metabolic derangements, the association between dietary carbohydrate intake and renal function remains unknown. The present study investigated the impact of dietary carbohydrate intake on the development of incident chronic kidney disease (CKD) in a large-scale prospective cohort with normal renal function. A total of 6746 and 1058 subjects without and with diabetes mellitus (DM) were analyzed, respectively. Carbohydrate intake was assessed by a 24-h dietary recall food frequency questionnaire. The primary endpoint was CKD development, defined as a composite of estimated glomerular filtration rate (eGFR) of &le, 60 mL/min/1.73 m2 and the development of proteinuria. CKD newly developed in 20.1% and 36.0% of subjects during median follow-ups of 140 and 119 months in the non-DM and DM subjects, respectively. Categorization of non-DM subjects into dietary carbohydrate density quartiles revealed a significantly higher risk of CKD development in the third and fourth quartiles than in the first quartile (P = 0.037 for first vs. third, P = 0.001 for first vs. fourth). A significant risk elevation was also found with increased carbohydrate density when carbohydrate density was treated as a continuous variable (P = 0.008). However, there was no significant difference in the incident CKD risk among those with DM according to dietary carbohydrate density quartiles. Carbohydrate-rich diets may increase the risk of CKD development in non-DM subjects.

본 연구는 2013 ~ 2017년 국민건강영양조사의 검진조사에 참여한 만 20세 이상 성인을 대상으로 고식이섬유 섭취 및 고탄수화물 섭취와 대사질환 간의 연관성을 확인하였다. 한국 성인의 평균 식이섬유 섭취량은 24.1 g/일이었으며, 탄수화물 섭취 수준이 증가할수록 식이섬유 섭취량도 증가하는 경향을 보였다. 고식이섬유 섭취와 대사증후군과의 연관성을 확인하기 위해 식이섬유 섭취량을 5분위수로 분류하였을 때, 충분섭취량 이상의 고식이섬유 섭취는 대사증후군 위험 감소와 연관이 있었다. 또한, 식이섬유 섭취가 탄수화물 섭취와 밀접한 관련이 있다는 점을 반영하여 고탄수화물 섭취와 대사질환과의 연관성을 식이섬유 섭취수준에 따라 확인하고자 하였다. 이에 식이섬유 충분섭취량을 기준으로 하여 성별로 저식이섬유 섭취 그룹과 고식이섬유 섭취 그룹으로 분류한 후, 탄수화물 에너지섭취비율과 대사질환과의 연관성을 분석한 결과 식이섬유 섭취수준에 따라 고탄수화물 섭취와 대사질환과의 연관성이 다름을 확인하였다. 저식이섬유 섭취 그룹에서는 남자의 경우 탄수화물 섭취가 삼분위군 일 때 일분위군에 비해 대사증후군과 죽상경화성 이상지질혈증의 교차비가 유의적으로 증가하고, 여자의 경우 탄수화물 섭취가 이분위군일 때 일분위군에 비해 고콜레스테롤혈증의 교차비가 유의적으로 증가하였다. 그리고 고식이섬유 섭취 그룹에서는 남자의 경우 탄수화물 섭취비율이 증가할수록 고중성지방혈증의 위험도가 증가하는 경향을 보였다. 본 연구의 결과는 한국 성인의 고식이섬유 섭취가 대사증후군의 낮은 위험도와 관련이 있다는 근거를 제시하였으며, 특히 남자의 경우 고탄수화물 섭취와 대사지표와의 연관성을 살펴볼 때 식이섬유 섭취 수준을 살펴보는 것이 필요함을 제시했다는데 의의가 있다. 따라서, 향후 우리나라 사람들을 대상으로 전향적인 연구를 실시하여 식이섬유, 탄수화물 섭취와 대사질환과의 인과관계를 검증할 필요가 있으며, 이를 통해 탄수화물의 질적 섭취에 대한 실질적인 섭취 지침을 마련할 필요가 있다.

In this study, juvenile beluga (Huso huso) were fed diets containing different carbohydrate to lipid ratios for 5 months. At the end of the culture period, proximate compositions of the fish carcasses (moisture, protein, fat, and ash) were measured. Then, qualitative changes in the fishes were evaluated during 24-days refrigeration (4°C), along with changes in their total volatile bases nitrogen (TVN), thiobarbituric acid (TBA), free fatty acids (FFA), pH, and muscle texture profile analysis. The results of proximate analysis of the carcasses showed that moisture, protein, and ash of the carcasses increased significantly (p < 0.05) with higher carbohydrate to lipid ratio, but fat content of the carcasses decreased significantly (p < 0.05). Further, during refrigeration, TVN, TBA, and FFA increased significantly in all the samples (p < 0.05), but these changes did not follow the same pattern in all the treatments. Tissue hardness decreased during preservation. Although pH changes in the fillets were low, t...

Acute carbohydrate-protein ingestion has been shown to improve steady-state endurance performance. This study compared the effects of carbohydrate and carbohydrate-protein ingestion on self-regulated simulated multiple-sprint sport performance. Nine participants completed two trials of a modified Loughborough Intermittent Shuttle Test involving 4 x 15 min blocks of regulated exercise followed by 2 x 15 min blocks of self-regulated exercise. Participants consumed 2.5 ml · kg(-1) of an 8% carbohydrate (CHO trial) or 6% carbohydrate plus 2% whey protein beverage (CHO-P trial) every 15 minutes. Distance covered (4.2%) and maximal speed (6.1%) decreased (P0.05) in the final 15 min of exercise, and whilst not significant, carbohydrate-protein elicited a very likely moderate (2.5: 90% confidence limits; ±1.4%) and possibly small (1.9: ±3.3%) improvement in each variable, respectively. Average running speed declined in the final 15 min of the CHO trial only (P = 0.002), with protein providing a likely small improvement (2.7%: ±2.5%). No differences (P0.05) between beverages were observed in body mass or plasma volume change, urine volume, heart rate, gut fullness, rating of perceived exertion (RPE), blood glucose or serum insulin. Blood urea concentration increased in the CHO-P trial only (mean ± SD: 45.4 ± 9.9 c.f. 39.2 ± 11.4 g · dL(-1), P = 0.003). These findings show carbohydrate-protein ingestion is likely to enhance multiple-sprint sport exercise performance above carbohydrate, potentially through altered central fatigue or increased protein oxidation.

Relatively few studies have been conducted on the effect of diet on the intestinal microbiota. We followed the response of the fecal microbiota to a carbohydrate-restricted diet in an obese volun- teer. The community composition was estimated through 16S rRNA gene sequence analysis. Bacteria of the Prevotella genus dominated the microbiota. Elimination of carbohydrates from diet triggered an immediate decrease in Prevotella, compensated by the increase in all other bacteria, and higher fluctuations in the community composition. Fecal microbiota changed back to its previous structure no later than 4 weeks after reintroducing carbohydrates in diet. Our results show the dependence of Prevotella on dietary carbohydrates and confirm the resilience of the microbiota to short-term dietary interventions. The potential link between Prevotella and obesity warrants further research.