Simple versus complex carbohydrates and health: A frequently neglected problem.

AIMS: For several decades, there has been a notion that dietary fat is made of different components (at least SAFA, MUFA, and PUFA) that exhibit different and sometimes contrasting effects when associated with health and diseases: coronary heart disease (CHD) and cardiovascular diseases (CVD) in general. A similar fact is not noticed in carbohydrates and their components considering that even some major recent studies on the issue did not segregate simple carbohydrates from complex carbohydrates. In this study, we aimed to stress this need. DATA SYNTHESIS: A small number of selected studies are presented and commented where segregation of simple from complex carbohydrates was either performed or disregarded to address the inconsistency of not disentangling them. CONCLUSIONS: If only total fats were considered in investigations where fat was studied, the present notion and attitude toward different roles of the various classes of fats, at least SAFA versus unsaturated (MUFA and PUFA) would be missing. Therefore, there is a need to disentangle simple from complex carbohydrates, and this should be systematically applied when addressing CHD or CVD mortality risks and their preventive measures.

A glycaemic index compendium of non-western foods.

Current international tables published on the glycaemic index (GI) of foods represent valuable resources for researchers and clinicians. However, the vast majority of published GI values are of Western origin, notably European, Australian and North American. Since these tables focus on Western foods with minimal inclusion of other foods from non-Western countries, their application is of limited global use. The objective of this review is to provide the GI values for a variety of foods that are consumed in non-Western countries. Our review extends and expands on the current GI tables in an attempt to widen its application in many other regions of the world.

Usual Dietary Intake of Resistant Starch in US Adults from NHANES 2015-2016.

BACKGROUND: Resistant starch (RS) confers many health benefits, mostly due to nonenzymatic human digestion and gut microbiota fermentation capacity. The usual intake of naturally occurring dietary RS in US adults is unclear. OBJECTIVES: This study estimated usual daily RS intake in grams per 1000 kcal in US adults by sex, age, and ethnic group, as well as the most frequent food category contributing to RS intake using data from the NHANES 2015-2016. METHODS: RS content of foods consumed was matched with Food and Nutrient Database for Dietary Studies food codes. The National Cancer Institute method was used to estimate adults' usual RS intake from 2 24-h dietary recalls. Day 1 RS contribution from food groups to overall RS intake was ranked for the total sample, across age-sex categories, and across ethnic groups. RESULTS: In total, 5139 US adults (48.4% male) had a mean daily usual intake of RS of 1.9 ± 0.0 g/(1000 kcal⋅d). Males and females had a similar intake of RS [2.0 ± 0.0 g compared with 1.9 ± 0.0 g/(1000 kcal⋅d)] with no differences between sexes within the same age category. When comparing ethnic groups within each age category, the non-Hispanic white males and females had significantly lower RS intake than all other ethnic groups [range: 1.7-1.8 compared with 2.1-2.3 g RS/(1000 kcal⋅d), respectively], with no differences among the other ethnic groups. French fries and other fried white potatoes, rice, and beans, peas, and legumes were the most frequently consumed food categories contributing to RS intake in all adults. CONCLUSIONS: US adults should improve the intake of natural RS food sources. Increasing RS intake will improve gastrointestinal health as a prebiotic and potentially increase insulin sensitivity with adequate consumption (e.g., ∼15 g/d).

Development of feed composition tables using a statistical screening procedure.

Millions of feed composition records generated annually by testing laboratories are valuable assets that can be used to benefit the animal nutrition community. However, it is challenging to manage, handle, and process feed composition data that originate from multiple sources, lack standardized feed names, and contain outliers. Efficient methods that consolidate and screen such data are needed to develop feed composition databases with accurate means and standard deviations (SD). Considering the interest of the animal science community in data management and the importance of feed composition tables for the animal industry, the objective was to develop a set of procedures to construct accurate feed composition tables from large data sets. A published statistical procedure, designed to screen feed composition data, was employed, modified, and programmed to operate using Python and SAS. The 2.76 million data received from 4 commercial feed testing laboratories were used to develop procedures and to construct tables summarizing feed composition. Briefly, feed names and nutrients across laboratories were standardized, and erroneous and duplicated records were removed. Histogram, univariate, and principal component analyses were used to identify and remove outliers having key nutrients outside of the mean ± 3.5 SD. Clustering procedures identified subgroups of feeds within a large data set. Aside from the clustering step that was programmed in Python to automatically execute in SAS, all steps were programmed and automatically conducted using Python followed by a manual evaluation of the resulting mean Pearson correlation matrices of clusters. The input data set contained 42, 94, 162, and 270 feeds from 4 laboratories and comprised 25 to 30 nutrients. The final database included 174 feeds and 1.48 million records. The developed procedures effectively classified by-products (e.g., distillers grains and solubles as low or high fat), forages (e.g., legume or grass-legume mixture by maturity), and oilseeds versus meal (e.g., soybeans as whole raw seeds vs. soybean meal expellers or solvent extracted) into distinct sub-populations. Results from these analyses suggest that the procedure can provide a robust tool to construct and update large feed data sets. This approach can also be used by commercial laboratories, feed manufacturers, animal producers, and other professionals to process feed composition data sets and update feed libraries.

Production, structure, and bioactivity of polysaccharide isolated from Tremella fuciformis XY.

Tremella fuciformis polysaccharide (TFP) is an important bioactive substance in Tremella, that contributes to its use as medicine and food. In this study, a novel fungus Tremella fuciformis XY was isolated and introduced to produce macromolecule polysaccharides (TFPB). The fermentation conditions were optimized and results demonstrates that the initial pH, optimal temperature and liquid volume were 6.0, 26 °C and 80 mL in a 500 mL flask, respectively. The maximum yield of TFPB was 9.05 ± 0.05 g/L, which is 59.05% higher than the basic yield (5.69 ± 0.02 g/L). The TFPB, purified by DEAE column, had a molecular weight (Mw) of 1.14 × 103 kDa and consisted mainly of mannose, glucuronic acid, glucose, galactose, xylose, and rhamnose at a molar ratio of 3.5:1.2:2:1.6:1.4:3. The structure of TFPB was preliminarily investigated by methylation analysis, infrared spectroscopy, and nuclear magnetic resonance analysis. The main linkage types were identified as 1,4-xylp, 1,4-manp, 1-xylp, 1-manp, 1,4-glcp, and 1,3,4-galp. Moreover, the antioxidant assays showed that TFPB could scavenge reactive oxygen species and hydroxyl radicals.

Carbohydrate quality changes and concurrent changes in cardiovascular risk factors: a longitudinal analysis in the PREDIMED-Plus randomized trial.

BACKGROUND: Overall quality of dietary carbohydrate intake rather than total carbohydrate intake may determine the risk of cardiovascular disease (CVD). OBJECTIVE: We examined 6- and 12-mo changes in carbohydrate quality index (CQI) and concurrent changes in several CVD risk factors in a multicenter, randomized, primary-prevention trial (PREDIMED-Plus) based on an intensive weight-loss lifestyle intervention program. METHODS: Prospective analysis of 5373 overweight/obese Spanish adults (aged 55-75 y) with metabolic syndrome (MetS). Dietary intake information obtained from a validated 143-item semiquantitative food-frequency questionnaire was used to calculate 6- and 12-mo changes in CQI (categorized in quintiles), based on 4 criteria (total dietary fiber intake, glycemic index, whole grain/total grain ratio, and solid carbohydrate/total carbohydrate ratio). The outcomes were changes in intermediate markers of CVD. RESULTS: During the 12-mo follow-up, the majority of participants improved their CQI by increasing their consumption of fruits, vegetables, legumes, fish, and nuts and decreasing their consumption of refined cereals, added sugars, and sugar-sweetened beverages. After 6 mo, body weight, waist circumference (WC), systolic and diastolic blood pressure (BP), fasting blood glucose, glycated hemoglobin (HbA1c), triglyceride levels, triglycerides and glucose (TyG) index, and TyG-WC decreased across successive quintiles of improvement in the CQI. After 12 mo, improvements were additionally observed for HDL cholesterol and for the ratio of total to HDL cholesterol. Favorable improvements (expressed in common units of SD and 95% CI) for quintile 5 compared with quintile 1 of CQI change were observed for most risk factors, including TyG-WC (SD -0.20; 95% CI -0.26, -0.15), HbA1c (SD -0.16; 95% CI -0.23, -0.10), weight (SD -0.12; 95% CI -0.14, -0.09), systolic BP (SD -0.11; 95% CI -0.19, -0.02) and diastolic BP (SD -0.11; 95% CI -0.19, -0.04). CONCLUSIONS: Improvements in CQI were strongly associated with concurrent favorable CVD risk factor changes maintained over time in overweight/obese adults with MetS. This trial was registered as ISRCTN 89898870.

Review article: biological mechanisms for symptom causation by individual FODMAP subgroups - the case for a more personalised approach to dietary restriction.

BACKGROUND: Due to the paucity of targeted therapy for irritable bowel syndrome (IBS), many patients turn to dietary modifications for symptom management. The combination of five subgroups of poorly absorbed and rapidly fermented carbohydrates-fructans, galacto-oligosaccharides, lactose, excess fructose and polyols-are thought to trigger gastrointestinal symptoms and are referred to collectively as "FODMAPs". AIMS: To examine the biological plausibility and mechanisms by which foods high in specific FODMAP subgroups cause symptoms, and to use this information to explore the possibility of targeting select dietary components to allow for a more personalised approach to dietary adjustment METHODS: Recent literature was analysed via search databases including Medline, PubMed and Scopus. RESULTS: Lactose, fructans and galacto-oligosaccharides have strong biologic plausibility for symptom generation due to lack of hydrolases resulting in distention from osmosis and rapid fermentation. However, excess fructose and polyols may only cause symptoms in specific individuals when consumed in high doses, but this remains to be established. There is evidence to suggest that certain patient characteristics such as ethnicity may predict response to lactose, but differentiation of other subgroups is difficult prior to dietary manipulation. CONCLUSIONS: While some clear mechanisms of action for symptom generation have been established, further research is needed to understand which patients will respond to specific FODMAP subgroup restriction. We suggest that clinicians consider in some patients a tailored, personalised "bottom-up" approach to the low-FODMAP diet, such as dietary restriction relevant to the patients' ethnicity, symptom profile and usual dietary intake.

Types of Carbohydrates Intake during Pregnancy and Frequency of a Small for Gestational Age Newborn: A Case-Control Study.

The objective of this study was to assess the relationship between consumption of different types of carbohydrates (CHO) during pregnancy and the risk of having a small for gestational age (SGA) newborn. A retrospective matched case⁻control design was carried out with a total of 518 mother-offspring pairs. A total of 137 validated items were included in the food frequency questionnaire (FFQ). Conditional logistic regression models were used to calculate crude odds ratios (cORs) and adjusted odds ratios (aORs) with 95% confidence intervals (CIs). Having more than 75 g/day of brown bread showed an inverse association with SGA (aOR = 0.64, CI 0.43⁻0.96). In contrast, an intake of industrial sweets more than once a day (aOR = 2.70, CI 1.42⁻5.13), or even 2⁻6 times a week (aOR = 1.84, CI 1.20⁻2.82), increased the odds of having a SGA newborn. During pregnancy, the higher the increase of wholegrain cereal and bread, the lower the possibility of having a SGA newborn, but the opposite occurred with refined sugar products-just consuming industrial bakery products or pastries twice a week increased the odds of having an SGA infant. Case⁻control studies cannot verify causality and only show associations, which may reflect residual confusion due to the presence of unknown factors. It is possible that a high consumption of sugary foods is a marker of a generally poor lifestyle.

Optimization of the microwave-assisted enzymatic extraction of Rosa roxburghii Tratt. polysaccharides using response surface methodology and its antioxidant and α-d-glucosidase inhibitory activity.

An extraction assay applying microwave-assisted enzymatic treatment for polysaccharides in Rosa roxburghii was developed using response surface methodology. The process parameters were optimized using Plackett-Burman (PB) design and central composite design to enhance the Rosa roxburghii polysaccharide extraction yield. Specific conditions (microwave power, 575W; microwave time, 18min; liquid-to-material ratio, 13.5:1mL/g; and enzyme dose, 6.5g/mL) generated an experimental yield of 36.21±0.62%, which closely agreed with the predicted value of 35.75%. Purification with a DEAE-52 cellulose column generated two fractions, PR-1 (from 6.2×103 to 7.4KDa) and PR-2 (from 559.8 to 106.6KDa). Subsequently, the antioxidant activity and α-d-glucosidase inhibitory activity of the two polysaccharide fractions were assessed; PR-1 exhibited stronger antioxidant activity and α-d-glucosidase inhibitory activity than PR-2. Finally, the monosaccharide composition of PR-1 was determined by HPLC using a 1-phenyl-3-methyl-5-pyrazolone precolumn derivatization method. The result showed that PR-1 contained mannose, ribose, rhamnose, glucosamine hydrochloride, glucuronic acid, galacturonic acid, glucose, galactose, arabinose and fucose with molar percentages of 2.1%, 0.54%, 2.1%, 0.26%, 1.5%, 22.7%, 24.0%, 26.4%, 19.6% and 0.89%, respectively.

Short communication: Supplementation of fructo-oligosaccharides does not improve insulin sensitivity in heavy veal calves fed different sources of carbohydrates.

Heavy veal calves (4-6 mo old) often develop problems with insulin sensitivity. This could lead to metabolic disorders and impaired animal growth performance. Studies in various animal species have shown that the supplementation of short-chain fructo-oligosaccharides (scFOS) can improve insulin sensitivity. We therefore studied the effects of scFOS supplementation on insulin sensitivity in heavy veal calves. Forty male Holstein-Friesian calves (BW = 190 ± 2.9 kg; age = 162 ± 1.4 d at the start of the trial) were fed either a control milk replacer (MR) diet or a diet in which one-third of the lactose was replaced by glucose, fructose, or glycerol for 10 wk prior to the start of the trial. At the start of the trial, calves were subjected to a frequently sampled intravenous glucose tolerance test to assess whole-body insulin sensitivity (muscle and hepatic insulin sensitivity). Calves within each dietary treatment group were ranked based on their insulin sensitivity value. Half of the calves received scFOS (12 mg/kg of BW) with the MR for 6 wk (supplementation was equally distributed over the insulin sensitivity range). Subsequently, a second frequently sampled intravenous glucose tolerance test was conducted to assess the effect of scFOS. In addition, fasting plasma levels of glucose, insulin, triglycerides, and cholesterol were determined to calculate the quantitative insulin sensitivity check index and triglyceride:high-density lipoprotein cholesterol ratio (fasting indicators of insulin sensitivity). Whole-body insulin sensitivity was low at the start of the trial and remained low in all groups [1.0 ± 0.1 and 0.8 ± 0.1 (mU/L)-1 · min-1 on average, respectively]. Supplementation of scFOS did not improve insulin sensitivity in any of the treatment groups. The quantitative insulin sensitivity check index and the triglyceride:high-density lipoprotein cholesterol ratio also did not differ between scFOS and non-scFOS calves and averaged 0.326 ± 0.003 and 0.088 ± 0.004, respectively, at the end of the trial. We conclude that scFOS supplementation does not improve insulin sensitivity in heavy veal calves regardless of the carbohydrate composition of the MR. This is in contrast to other animals (e.g., dogs and horses), where scFOS supplementation did improve insulin sensitivity. The absence of an effect of scFOS might be related to the dosage or to metabolic differences between ruminants and nonruminants. Increasing evidence indicates that dietary interventions in veal calves have little or no effect on insulin sensitivity, possibly because of low levels of insulin sensitivity.

Association between a dietary carbohydrate index and cardiovascular disease in the SUN (Seguimiento Universidad de Navarra) Project.

BACKGROUND AND AIMS: Beyond the quantity of carbohydrate intake, further research is needed to know the relevance of carbohydrate quality following operational indices. No previous longitudinal study has assessed the association between an index for quality of dietary carbohydrate intake and the risk of cardiovascular disease (CVD). Here, we examined the association between a carbohydrate quality index (CQI) and the risk of CVD. METHODS AND RESULTS: We used a validated semi-quantitative 136-item food-frequency questionnaire (FFQ) in a prospective follow-up study of 17,424 middle-aged adults from Spain. The CQI was defined by four criteria: dietary fiber intake, glycemic index, whole-grain/total-grain carbohydrate ratio, and solid/total carbohydrate ratio. We observed 129 incident cases of CVD during 10.1 y of median follow-up. An inverse association for CQI was found (hazard ratio = 0.44, 95% confidence interval (CI): 0.25-0.78 for the highest versus the lowest tertile, p for trend = 0.008). Participants in the highest tertile of the whole-grain/total-grain carbohydrate ratio had 47% lower risk of CVD (95% CI: 0.33-0.85, p for trend = 0.008). Participants with higher baseline CQI and higher baseline energy from carbohydrates had the lowest risk of CVD. CONCLUSION: In this Mediterranean cohort, a better quality of dietary carbohydrates measured by the CQI, showed a significant inverse association with the incidence of CVD. Specially, a higher proportion of carbohydrates from whole grains was strongly inversely associated with CVD. "Heart-healthy" diets should be focused not only on carbohydrate quantity but also on a multidimensional assessment of the type and quality of carbohydrates.

The Truth about Sugar.

Sugars are used by the industry to enhance the attractiveness of foods and drinks. These added sugars, or 'free sugars', are not easily identified in food or drink labels. Certain manufactured foods and drinks with 'safe' names, such as dried fruit and fruit juice, still contain free sugars and can be confusing. Guidance states that daily consumption of free sugars should be less than 10% of total energy intake (no more than 5% in the UK). However, it is found that both tooth decay and obesity are associated with consumption of free sugars in large quantities and at inappropriate times.

Carbohydrate quality, weight change and incident obesity in a Mediterranean cohort: the SUN Project.

BACKGROUND/OBJECTIVES: To evaluate the association between the carbohydrate quality index (CQI) and weight change or incident overweight/obesity (body mass index ⩾25 kg/m(2)) in the 'Seguimiento Universidad de Navarra (SUN)' cohort. SUBJECTS/METHODS: A total of 8741 participants who were initially free of overweight/obesity were followed up for a median of 7.9 years. We evaluated at baseline the CQI according to four criteria: dietary fiber intake, glycemic index, whole grains/total grains ratio and solid carbohydrates/total carbohydrates ratio. Subjects were classified into quintiles according to CQI. Weight was recorded at baseline and updated every 2 years during follow-up. RESULTS: Increasing CQI of diet was not significantly associated with lower weight gain, although participants in the highest quintile had the lowest average crude weight gain (+211 g/year). We observed 1862 incident cases of overweight/obesity during follow-up. CQI was significantly associated (P for trend 0.006) with a lower risk of overweight/obesity; adjusted odds ratio for the fourth and fifth quintiles were 0.81 (95% confidence interval (CI): 0.66-0.99) and 0.74 (95% CI: 0.60-0.92), respectively. CONCLUSIONS: In this Mediterranean cohort, CQI showed a significant inverse association with the incidence of overweight/obesity, which highlights that carbohydrate intake guidelines related to obesity prevention should be focused on improving the CQI of the diet.

Invited review: Enteric methane in dairy cattle production: quantifying the opportunities and impact of reducing emissions.

Many opportunities exist to reduce enteric methane (CH4) and other greenhouse gas (GHG) emissions per unit of product from ruminant livestock. Research over the past century in genetics, animal health, microbiology, nutrition, and physiology has led to improvements in dairy production where intensively managed farms have GHG emissions as low as 1 kg of CO2 equivalents (CO2e)/kg of energy-corrected milk (ECM), compared with >7 kg of CO2 e/kg of ECM in extensive systems. The objectives of this review are to evaluate options that have been demonstrated to mitigate enteric CH4 emissions per unit of ECM (CH4/ECM) from dairy cattle on a quantitative basis and in a sustained manner and to integrate approaches in genetics, feeding and nutrition, physiology, and health to emphasize why herd productivity, not individual animal productivity, is important to environmental sustainability. A nutrition model based on carbohydrate digestion was used to evaluate the effect of feeding and nutrition strategies on CH4/ECM, and a meta-analysis was conducted to quantify the effects of lipid supplementation on CH4/ECM. A second model combining herd structure dynamics and production level was used to estimate the effect of genetic and management strategies that increase milk yield and reduce culling on CH4/ECM. Some of these approaches discussed require further research, but many could be implemented now. Past efforts in CH4 mitigation have largely focused on identifying and evaluating CH4 mitigation approaches based on nutrition, feeding, and modifications of rumen function. Nutrition and feeding approaches may be able to reduce CH4/ECM by 2.5 to 15%, whereas rumen modifiers have had very little success in terms of sustained CH4 reductions without compromising milk production. More significant reductions of 15 to 30% CH4/ECM can be achieved by combinations of genetic and management approaches, including improvements in heat abatement, disease and fertility management, performance-enhancing technologies, and facility design to increase feed efficiency and life-time productivity of individual animals and herds. Many of the approaches discussed are only partially additive, and all approaches to reducing enteric CH4 emissions should consider the economic impacts on farm profitability and the relationships between enteric CH4 and other GHG.

[Foods as sources of mono and disaccharides: biochemical and metabolic aspects]. / Los alimentos como fuente de mono y disacáridos: aspectos bioquímicos y metabólicos.

Carbohydrates are important and necessary components of human diet. Although they primarily play an energetic function, they also have structural and functional roles. According to the European Food Safety Authority, carbohydrate intake should range between 45 and 60 percent of the energy in adults and children older than one year of age. An important part of carbohydrates available in foods are mono and disaccharides, commonly referred to as sugars. Dietary sources of sugars include fruits, fruit juices, vegetables, milk and milk products, and foods containing added sucrose and starch hydrolyzates. Despite their importance in daily life, there is currently no clear and adequate terminology on the various types of carbohydrates, particularly sugars. Nor are there available sugar intake recommendations or food composition tables. Without these recommendations or reference values, dietary unbalances might occur, which subsequently may end in the premature onset of most chronic or degenerative diseases of our society. The aims of the present work are: to classify dietary carbohydrates, to define the biochemical and common terms for sugars, to explain their nutritional value and their metabolism as well as their food sources and to carry out a SWOT (Strengths, Weaknesses, Opportunities, Threats) analysis about the nomenclature and dietary intakes of sugars.

Los hidratos de carbono constituyen una parte importante y necesaria en la alimentación humana. Aunque desempeñan una función primordialmente energética, también tienen funciones estructurales y funcionales. Según la Agencia Europea para la Seguridad Alimentaria, la ingesta de hidratos de carbono debe oscilar entre un 45 y 60% de la energía en adultos y niños mayores de un año. Una parte importante de los hidratos de carbono disponibles en los alimentos la componen los mono y disacáridos, comúnmente denominados azúcares. Las principales fuentes dietéticas de azúcares son las frutas, los zumos de fruta, algunos productos vegetales, la leche y los productos lácteos, y los alimentos que contengan sacarosa añadida e hidrolizados de almidón. A pesar de ser fundamentales en nuestra vida diaria, no existe una terminología adecuada y clara sobre los diversos tipos de hidratos de carbono, y de forma muy especial de los azúcares. Tampoco en lo referente a las recomendaciones de ingesta y contenido en los alimentos. Sin recomendaciones ni valores de referencia, pueden producirse desajustes alimentarios, que pueden asociarse con la aparición precoz de la mayor parte de las enfermedades crónicas o degenerativas en nuestra sociedad. Los objetivos de este trabajo son: clasificar los hidratos de carbono presentes en los alimentos, establecer definiciones claras sobre todos los términos bioquímicos y comunes relacionados con los azúcares, explicar su valor nutricional y describir su metabolismo, así como las fuentes alimentarias que contienen tanto mono como disacáridos y, finalmente, realizar un análisis DAFO (Debilidades, Amenazas, Fortalezas y Oportunidades) sobre la nomenclatura y las ingestas de azúcares.

Carbohydrate quality is not associated with liver enzyme activity and plasma TAG and HDL concentrations over 5 years in an older population.

Non-alcoholic fatty liver disease (NAFLD) is closely associated with insulin resistance and obesity. Hence, carbohydrate quality could be of relevance to the risk of NAFLD, but prospective data are lacking. The aim of the present study was to investigate longitudinal associations between carbohydrate quality (including dietary glycaemic index (GI) and intakes of sugar, starch and fibre) and markers of liver function in an older Australian population. The analysis was based on 866 participants ( ≥ 49 years) of the Blue Mountains Eye Study with fasting blood specimens and dietary intake data at baseline and 5-year follow-up. Multi-level mixed regression analysis was used to relate dietary GI and sugar, starch and fibre intake to the liver enzymes alanine aminotransferase (ALT) and γ-glutamyltransferase (GGT), as well as fasting TAG and HDL-cholesterol (HDL-C). After adjustment for potential confounding factors, a lower fibre intake was cross-sectionally related to higher GGT (P= 0.02) and fasting TAG (P= 0.002) levels, with fruit fibre being the most relevant fibre source (P= 0.095 for GGT; P= 0.003 for TAG). A higher dietary GI was associated with lower HDL-C (P= 0.046). Changes in carbohydrate quality during 5 years were not related to changes in ALT, GGT, TAG or HDL-C (P≥ 0.08). In conclusion, the absence of longitudinal associations between carbohydrate quality and liver enzymes and serum lipids in this older population does not support a major role of carbohydrate nutrition in liver function among the elderly.

Insulin resistance predicts the effectiveness of different glycemic index diets on weight loss in non-obese women.

OBJECTIVE: The present study aimed to evaluate whether baseline insulin resistance (IR) modify weight change associated to glycemic index (GI) of the diet. METHOD: This is a secondary analysis of a randomized GI intervention according to baseline HOMA-IR. Middle-aged (25-45 years), non-obese (BMI 23-29.9 kg/m²) women were randomized to low or high GI diets matched on total energy, macronutrient composition, and fiber content. Both groups received dietary counseling based on a small energy restriction (100-300 kcal/day). Women were classified in two groups according to their baseline HOMA-IR: IR (n = 64) and non-IR (n = 121). RESULTS: At baseline, IR and non-IR groups had similar BMI (26.7 vs. 26.3 kg/m²; p = 0.21), but the IR group presented with higher waist circumference (82.7 vs. 80.8 cm; p = 0.02) and showed greater weight loss after 12 months of follow-up (-1.6 vs. -1.1 kg; p = 0.01), mainly among those in a high-GI diet (-2.1 vs. -1.0 kg; p = 0.005) compared to the non-IR group (-1.4 vs. -0.8 kg; p = 0.04). CONCLUSIONS: The high-GI group showed statistically significant higher reduction in body weight, mainly among those women with baseline IR . Low-GI diet did not facilitate weight loss neither in IR women nor in non-IR women.