ABSTRACT
CONTEXT: Diseases related to excessive sugar consumption have become a public health concern. However, there may be a direct association between the consumption of artificial sweeteners and changes in body weight. OBJECTIVE: The aim was to evaluate potential industry financial conflicts of interest in publications on the relationship between high-intensity sweetener consumption and changes in body weight in observational and intervention studies. DATA SOURCES: The systematic review used the Medline, Embase, Cochrane, Scopus, and the VHL (Virtual Health Library) Regional Portal, including the LILACS databases. The PICOS strategy were used in the search strategy for intervention studies and for observational studies used the exposure factor as the criterion. DATA EXTRACTION: Inclusion criteria were observational and intervention studies in adults, without population or health status restrictions, without restriction on the year of publication, but restricted to full articles in Portuguese, English, and Spanish. Exclusion criteria were humans younger than 18 years, cross-sectional studies, and animal and in vitro studies. DATA ANALYSIS: There were extracted effect estimates, odds ratios, and linear associations, quantifying the effects per unit of intake of high-intensity sweeteners. The risk of bias in the intervention studies was assessed using the Cochrane Collaboration Risk of Bias tool (RoB). The Newcastle Ottawa Scale was used for observational studies (case-control and cohort). CONCLUSION: Most clinical trials favor using artificial sweeteners and receive contributions from the food industry. Observational studies, for the most part, show that the use of artificial sweeteners is unfavorable. In these studies, there was no sponsorship from the food industry, only from regulatory bodies. This result suggests that studies that had the support of the food industry had their influence on their outcomes. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration no: CRD42016036204.
ABSTRACT
PURPOSE OF REVIEW: This review aims to critically examine how VLCKD affects plasma lipoprotein, lipid and cholesterol metabolism. Cardiovascular disease is a worldwide health problem affecting millions of people and leading to high rates of mortality and morbidity. There is a well-established association between cardiovascular disease and circulating cholesterol. Various dietary recommendations are currently available for the management of dyslipidemia. RECENT FINDINGS: The very low-calorie ketogenic diet (VLCKD) is becoming increasingly popular as a treatment option for several pathological conditions, including dyslipidemia. In addition to being low in calories, the VLCKD's main feature is its unique calorie distribution, emphasizing a reduction in carbohydrate consumption in favor of fat as the primary calorie source. Lowering calorie intake through a VLCKD can reduce the endogenous production of cholesterol. However, if the foods consumed are from animal sources, dietary cholesterol intake may increase due to the higher fat content of animal products. When combined, these dietary practices may have opposing effects on plasma cholesterol levels. Studies investigating the impact of VLCKD on plasma cholesterol and low-density lipoprotein cholesterol levels report contradictory findings. While some studies found an increase in low-density lipoprotein cholesterol levels, others showed a decrease in total cholesterol and low-density lipoprotein cholesterol, along with an increase in high-density lipoprotein cholesterol.
Subject(s)
Caloric Restriction , Diet, Ketogenic , Lipid Metabolism , Humans , Dyslipidemias/diet therapy , Cholesterol/blood , Energy Intake , Cardiovascular Diseases/prevention & control , Cardiovascular Diseases/diet therapy , Cholesterol, Dietary , Cholesterol, LDL/bloodABSTRACT
Bakery products, including biscuits, cakes and breads, generally present a high content of simple sugars of rapid absorption, high fat content and low amount of dietary fiber, which make them highly caloric foods. Although sucrose is a very important ingredient in bakery products for its preservation characteristics and a significant source of energy, there is a growing interest in replacing this sugar with alternative substances, such as high-intensity sweeteners (HIS) that provide sweetness with no or low calories. In Brazil, there is no data on the use of HIS in this class of food. Therefore, the objective of this study was to evaluate the presence of HIS in baked food commercially available in the country and estimate the dietary exposure to these food additives. For that, an analytical method was established for the simultaneous determination of nine HIS in bakery products using ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). Sample preparation steps were required based on mechanical kneading for homogenization, hexane extraction of fats, dilution in mobile phase and vortex homogenization, prior to injection into the system. The results obtained during validation showed that coefficients of variation (CV%) for precision were lower than 13.8% and the accuracy was between 91.6% and 109.1%. Aspartame, acesulfame potassium, sodium cyclamate, saccharin, sucralose and steviol glycosides were found in the samples, used alone or in combinations of up five substances. Steviol glycosides were the most found HIS in biscuit samples, while sucralose was the most common sweetener in cake and bread samples. Analysis of product labels revealed only three different claims, .i.e. 'no sugar', 'no added sugar' and 'zero sugar', with the latter being found in 70% of the samples. Exposure to HIS through the consumption of bakery products estimated per eating occasion showed no concerns regarding toxicological risk.
Subject(s)
Dietary Exposure , Sweetening Agents , Tandem Mass Spectrometry , Sweetening Agents/analysis , Brazil , Humans , Dietary Exposure/analysis , Chromatography, High Pressure Liquid , Food Analysis , Bread/analysisABSTRACT
Calorie restriction is a nutritional intervention that reproducibly protects against the maladaptive consequences of cardiovascular diseases. Pathological cardiac hypertrophy leads to cellular growth, dysfunction (with mitochondrial dysregulation), and oxidative stress. The mechanisms behind the cardiovascular protective effects of calorie restriction are still under investigation. In this study, we show that this dietetic intervention prevents cardiac protein elevation, avoids fetal gene reprogramming (atrial natriuretic peptide), and blocks the increase in heart weight per tibia length index (HW/TL) seen in isoproterenol-induced cardiac hypertrophy. Our findings suggest that calorie restriction inhibits cardiac pathological growth while also lowering mitochondrial reverse electron transport-induced hydrogen peroxide formation and improving mitochondrial content. Calorie restriction also attenuated the opening of the Ca2+-induced mitochondrial permeability transition pore. We also found that calorie restriction blocked the negative correlation of antioxidant enzymes (superoxide dimutase and glutatione peroxidase activity) and HW/TL, leading to the maintenance of protein sulphydryls and glutathione levels. Given the nature of isoproterenol-induced cardiac hypertrophy, we investigated whether calorie restriction could alter cardiac beta-adrenergic sensitivity. Using isolated rat hearts in a Langendorff system, we found that calorie restricted hearts have preserved beta-adrenergic signaling. In contrast, hypertrophic hearts (treated for seven days with isoproterenol) were insensitive to beta-adrenergic activation using isoproterenol (50 nM). Despite protecting against cardiac hypertrophy, calorie restriction did not alter the lack of responsiveness to isoproterenol in isolated hearts harvested from isoproterenol-treated rats. These results suggest (through a series of mitochondrial, oxidative stress, and cardiac hemodynamic studies) that calorie restriction possesses beneficial effects against hypertrophic cardiomyopathy.
Subject(s)
Calcium , Caloric Restriction , Oxidative Stress , Animals , Rats , Calcium/metabolism , Male , Cardiomegaly/metabolism , Cardiomegaly/prevention & control , Electron Transport , Isoproterenol , Mitochondria/metabolism , Mitochondria, Heart/metabolism , Rats, Sprague-DawleyABSTRACT
OBJECTIVE: To examine the relationship between pressure injury (PI) development and achievement of nutritional goals (protein and caloric), as well as consider the clinical conditions, hospitalisation factors, and risk assessment for PI development in patients who are critically ill and receiving enteral nutrition (EN) in the intensive care unit (ICU). METHOD: An observational cohort study was conducted in the ICU of the University Hospital in São Paulo, Brazil. Inclusion criteria were as follows: age ≥18 years; length of ICU stay ≥24 hours; without PI at ICU admission; and receiving EN exclusively during ICU stay. The development of PI was considered the dependent variable. The Chi-squared test was applied to compare categorical variables, and the Mann-Whitney U test was used to compare continuous variables between groups of patients with and without a PI. The analysis of the achievement of nutritional goals was performed using Fisher's exact test. A significance level of 5% (p-value<0.05) and a confidence interval (CI) of 95% was adopted in all statistical tests. RESULTS: A total of 181 patients met the inclusion criteria, of whom 102 (56.4%) were male and 79 (43.6%) were female. Mean age was 55.1 years, and mean length of ICU stay was 17.5 days. PI development was associated with not achieving nutritional goals. There was a higher percentage (65.3%) of patients without a PI when both protein and caloric goals were achieved. In contrast, 45.6% of patients developed a PI when the goals were not achieved. The mean days for sedation, vasoactive drugs and mechanical ventilation were all significantly higher in patients who developed a PI (p<0.001). CONCLUSION: There was a significant association between patients developing a PI and deficits in caloric and protein intake. Patients who did not develop PIs had a greater calorie and protein intake compared with those who developed a PI.
Subject(s)
Enteral Nutrition , Pressure Ulcer , Female , Humans , Male , Middle Aged , Brazil/epidemiology , Critical Care , Energy Intake , Enteral Nutrition/adverse effects , Goals , Intensive Care Units , Length of Stay , Pressure Ulcer/prevention & control , AdultABSTRACT
Objetivo: Objetiva-se avaliar a relação entre consumo de proteínas (CP), atividade física (AF) e massa muscular (MM) em indivíduos com 60 anos ou mais de idade. Metodologia: Trata-se de um estudo prospectivo a partir da linha de base e segunda onda do estudo ELSA-Brasil. O CP foi avaliado por meio de um questionário de frequência alimentar semiquantitativo (QFA). A AF foi mensurada pelo International Physical Activity Questionnaire (IPAQ). A MM foi estimada por meio de equação de predição, e calculada a diferença de MM entre a 2a e a 1a onda. Análises bivariadas foram realizadas adotando o valor de p < 0,05. Para as análises multivariadas, utilizou-se a regressão de Poisson, com quatro modelos distintos, que incluíram as covariáveis com valor de p < 0,20. Utilizou-se o pacote estatístico SPSS versão 21. Resultados: A amostra foi constituída de 2216 idosos, sendo 55,10% de mulheres, com média de idade de 65,20 ± 4,15. Indivíduos com redução de MM entre as duas ondas estão situados no primeiro quartil de consumo de proteína. Além disso, a média de AF mostrou diferença significativa entre os grupos e a AF no lazer apenas para as mulheres (p < 0,05). Após ajuste por variáveis sociodemográficas, de saúde e hábitos de vida, indivíduos com menor consumo de proteínas apresentaram risco de 1,45 (1,29 1,63) de apresentar MM diminuída. Conclusões: O menor CP e AF forte estão associados à MM diminuída, e aqueles com menor CP no primeiro e segundo quartis apresentam maior risco de possuir MM diminuída. (AU)
Objective: The objective was to evaluate the relationship between protein consumption, physical activity, and muscle mass in individuals aged ≥ 60 years. Methods: This prospective study was based on the baseline and second wave of the ELSA Brazil study. Protein consumption was assessed using a semiquantitative food frequency questionnaire. Physical activity was measured using the International Physical Activity Questionnaire. Muscle mass was estimated using a prediction equation, and the difference in MM between the first and second waves was calculated. Bivariate analyses were performed, with p < 0.05 considered significant. Multivariate analysis consisted of 4 Poisson regression models including covariates with p < 0.20. The statistical analysis was performed in IBM SPSS Statistics 21. Results: The sample included 2216 older adults, 55.10% of whom were women, with a mean age of 65.20 (SD, 4.15). Participants whose muscle mass decreased between the waves were in the first quartile of protein consumption. Mean physical activity significantly differed between the groups, while leisure-time physical activity differed only for women (p < 0.05). After adjusting for sociodemographic, health, and lifestyle variables, participants with lower protein intake had a 1.45 (1.291.63) relative risk of muscle mass loss. Conclusions: Lower protein consumption and higher physical activity were associated with decreased muscle mass, and those with protein consumption in the first and second quartiles are at higher risk of muscle mass loss. (AU)
Subject(s)
Humans , Aged , Aged, 80 and over , Body Composition , Protein-Energy Malnutrition , Muscle, SkeletalABSTRACT
PURPOSE OF REVIEW: This review aims to explore in-depth the different aspects of the association between very low-calorie ketogenic diet (VLCKD), obesity and obesity-related thyroid dysfunction. RECENT FINDINGS: The VLCKD, proposed as a non-pharmacological strategy for the management of certain chronic diseases, is becoming increasingly popular worldwide. Initially used to treat epilepsy, it has been shown to be effective in controlling body weight gain and addressing various pathophysiological conditions. Research has shown that a low-calorie, high-fat diet can affect thyroid hormone levels. Weight loss can also influence thyroid hormone levels. Studies have suggested that long-term use of VLCKD for refractory epilepsy may be related to the development of hypothyroidism, with an effect seen in various populations. In particular, women with obesity following VLCKD tend to have reduced T3 levels. We propose further research to unravel the underlying mechanisms linking VLCKD to obesity and obesity-related thyroid dysfunction.
Subject(s)
Caloric Restriction , Diet, Ketogenic , Hypothyroidism , Obesity , Humans , Obesity/diet therapy , Hypothyroidism/diet therapy , Weight Loss , Thyroid Hormones/blood , Thyroid Gland , Female , Epilepsy/diet therapyABSTRACT
This study assesses the feasibility of calorie restriction (CR) and time-restricted feeding (TRF) in overweight and obese cancer patients who realized little to no physical activity undergoing curative radiotherapy, structured as a prospective, interventional, non-randomized open-label clinical trial. Of the 27 participants initially enrolled, 21 patients with breast cancer were selected for analysis. The participants self-selected into two dietary interventions: TRF, comprising a sugar and saturated fat-free diet calibrated to individual energy needs consumed within an 8 h eating window followed by a 16 h fast, or CR, involving a 25% reduction in total caloric intake from energy expenditure distributed across 4 meals and 1 snack with 55% carbohydrates, 15% protein, and 30% fats, excluding sugars and saturated fats. The primary goal was to evaluate the feasibility of these diets in the specific patient group. The results indicate that both interventions are effective and statistically significant for weight loss and reducing one's waist circumference, with TRF showing a potentially stronger impact and better adherence. Changes in the LDL, HDL, total cholesterol, triglycerides, glucose and insulin were not statistically significant.
Subject(s)
Neoplasms , Overweight , Humans , Overweight/therapy , Caloric Restriction , Prospective Studies , Obesity/therapy , Neoplasms/complications , Neoplasms/radiotherapyABSTRACT
BACKGROUND: Patients with cancer receiving adequate enteral nutrition (EN) have improved clinical outcomes. Unfortunately, discrepancies may exist between the amounts prescribed and received. This study aimed to investigate: (1) the receiving exclusive EN, (2) the relationship between inadequacy and unfavorable outcomes, and (3) the impact of inadequate EN administration on the survival of patients with cancer. METHODS: This study included hospitalized patients with solid tumors who exclusively received EN and were evaluated using data extracted from electronic medical records. Nutritional risk was evaluated using Nutritional Risk Screening (NRS - 2002). EN adequacy was assessed from days 3-7 of hospitalization. Calorie and protein delivery by EN was classified as adequate (≥80 % of EN administration) or inadequate (<80 % of EN administration). Data were analyzed using dispersion and Bland-Altman plots, Pearson's chi-square and Fisher's exact tests, and Kaplan-Meier survival curves. RESULTS: A total of 114 patients were evaluated (63.9 ± 13.1 years of age, 67.5 % male, 32.5 % with head and neck cancer, and 86.8 % at nutritional risk). During the 5-day evaluation period, only 14 % of the patients received the mean volume, proteins, and calories according to the EN prescription. A relationship was observed between inadequate EN (<80 %) and 30-day in-hospital mortality. This result was confirmed by Kaplan-Meier survival analysis (p = 0.020), which showed a survival benefit in patients at nutritional risk who received adequate calories and protein. CONCLUSION: This study demonstrated significant caloric and protein deficits related with EN. Furthermore, adequate calorie and protein administration could contribute to improved survival in patients with cancer who are at a risk of malnutrition, however, randomized controlled trials are required to confirm whether adequate calorie administration could contribute to improved survival.
Subject(s)
Malnutrition , Neoplasms , Humans , Male , Aged , Female , Enteral Nutrition , Energy Intake , Hospitalization , Neoplasms/therapyABSTRACT
BACKGROUND: To assess oxidative effects induced by a high-calorie diet on the retina of Wistar rats and test the antioxidative effects of carnosine supplementation. METHODS: Wistar rats were randomly divided into the following groups: standard diet (SD), high-calorie diet (HcD), standard diet + carnosine (SD + Car), and high-calorie diet + carnosine (HcD + Car). The body weight, adiposity index, plasma glucose, total lipids, high-density lipoprotein (HDL), low-density lipoprotein (LDL), uric acid, creatinine, and triglycerides of the animals were evaluated. The retinas were analyzed for markers of oxidative stress. Hydrogen peroxide production was assessed by 2',7'-dichlorodihydrofluorescein diacetate (DCF) oxidation. The total glutathione (tGSH), total antioxidant capacity (TAC), protein carbonyl, and sulfhydryl groups of the antioxidant system were analyzed. RESULTS: TAC levels increased in the retinas of the SD + Car group compared to the SD group (p < 0.05) and in the HcD + Car group compared to the HcD group (p < 0.05). The levels of GSH and the GSSH:GSSG ratio were increased in the HcD + Car group compared to the SD + Car group (p < 0.05). An increase in the retinal carbonyl content was observed in the HcD group compared to the SD group (p < 0.05) and in the HcD + Car group compared to the SD + Car group (p < 0.05). A high-calorie diet (HcD) was also associated with a decrease in retinal sulfhydryl-type levels compared to the SD group (p < 0.05). CONCLUSION: The results suggest that feeding a high-calorie diet to rats can promote an increase in carbonyl content and a reduction in sulfhydryl groups in their retinas. The administration of carnosine was not effective in attenuating these oxidative markers. TRIAL REGISTRATION: Animal Ethics Committee of Botucatu Medical School - Certificate number 1292/2019.
Subject(s)
Antioxidants , Carnosine , Rats , Animals , Antioxidants/pharmacology , Carnosine/pharmacology , Rats, Wistar , Oxidative Stress , Diet , Dietary SupplementsABSTRACT
Government regulatory actions and public policies have been recently implemented in Brazil due to the excessive consumption of sugar. Therefore, it becomes relevant to determine the levels of high-intensity sweeteners in tabletop sweeteners consumed by the Brazilian population. Thus, an analytical method was developed and validated for the simultaneous determination of nine sweeteners (acesulfame potassium, aspartame, advantame, sodium cyclamate, neotame, saccharin, sucralose, stevioside, and rebaudioside A) by using ultra-high performance liquid chromatography coupled to mass spectrometry in tandem. The sample preparation encompassed only dilution steps. The method was validated taking into account the parameters of linearity, precision, accuracy, and matrix effects. The analytes were determined in two different batches of 21 commercial liquid and powder tabletop sweeteners available on the local market, totaling 42 samples. A minimum of one and a maximum of four sweeteners were found in the analyzed products and sweeteners that were not described on the label were not detected. It is expected that the established method can be used in monitoring programs and that the presented results can contribute to exposure assessments performed nationally.
Subject(s)
Non-Nutritive Sweeteners , Sweetening Agents , Sweetening Agents/analysis , Non-Nutritive Sweeteners/analysis , Powders , Aspartame/analysis , Food AdditivesABSTRACT
Prior studies on perceived healthiness of foods have often compared nutrient and hedonic claims, neglecting comparisons to a control condition. The effect of food claims focusing on the food processing level has received considerably less research attention, although food processing has been included in dietary guidelines in Brazil. Thus, the present study aimed to explore the effect of a control and processing claim, additionally to the effects of a nutrient. and hedonic claim, on perceptions related to a food item typically considered "less healthy" (chocolate cake). We further compared these effects between Brazil and Germany, a country where food processing is currently not included in dietary guidelines. A total of 634 lay adults were recruited in a cross-sectional online study and randomised to see the photo of a piece of cake with one of the four different claim conditions and to report their health-related perceptions of the cake. The main analyses included two-way ANCOVAs (4 claims x 2 countries) for each dependent variable controlled for gender, age and level of hunger; followed by post hoc tests. Overall, results revealed that in both countries, the claims highlighting nutrients or processing aspects rendered the perceptions of the cake healthier compared to the control claim. These effects were more pronounced among Brazilian than among German participants. Food-related perceptions mostly did not differ between the hedonic and control claim and did not differ at all between the nutrient and processing claims. In conclusion, it is noteworthy that, even for an inherently considered "less healthy food item" (chocolate cake) nutrient and processing claims increase healthiness perceptions. While our findings may imply that in both countries lay people are highly susceptible to nutrient claims, food processing aspects seem to be similarly relevant.
ABSTRACT
Previously, we demonstrated a non-linear association between meal caloric intake and meal energy density (ED, kcal/g) in data from a controlled trial in the US and from free-living participants in the UK [1]. In both datasets, meal caloric intake increased with ED in lower energy-dense meals (below â¼1.75 kcal/g) and decreased in higher energy-dense meals (above â¼1.75 kcal/g). In the current study, we sought to explore whether this pattern extends to data from free-living participants in Argentina (N = 2738 meals) and Malaysia (N = 4658 meals). Again, a significant breakpoint was found in both the Argentinean (2.04 kcal/g (SE = 0.06)) and Malaysian (2.17 kcal/g (SE = 0.06)) datasets with mean centered meal caloric intake increasing with ED below the breakpoint and decreasing above the breakpoint. These results lend further support for our two-component theoretical model of meal size (g) in which a volume signal is dominant in lower energy-dense meals and a calorie-content signal is dominant in higher energy-dense meals. Together, our research adds to evidence supporting human sensitivity to calories and exposes a complexity in the correspondence between meal energy content and meal size in everyday (non-manipulated) meals. Further research is needed to provide causal evidence for this sensitivity and whether individual variation impacts meal size and energy balance.
Subject(s)
Energy Intake , Meals , Humans , Argentina , MalaysiaABSTRACT
Research background: The extensive cultivation of bananas (Musa sp.) is related to producing tons of residues, such as leaves, pseudostems and bracts (inflorescences). The banana bract is a commercially interesting residue due to its dietary fibre content and high antioxidant potential. With this in mind, this study evaluates the effects of administering banana bract flour in animal models fed a cafeteria diet. Experimental approach: Thirty-two male rats were divided into 4 groups: (i) control diet, (ii) control diet with 10 % banana bract flour, (iii) hypercaloric diet, and (iv) hypercaloric diet with 10 % bract banana flour. The study was conducted for 12 weeks and included analysis of phenolic compounds, assessment of the antioxidant effect of banana bract flour, determination of serum biochemical parameters (glucose, total cholesterol, triglycerides, aspartate aminotransferase (AST), alanine transaminase (ALT), amylase, albumin, uric acid, creatine, total protein, and oral glucose), determination of faecal fat content, and histomorphological analysis of the liver, pancreas and adipose tissue. In addition, molecular parameters such as IL6, total and phosphorylated JNK, total and phosphorylated IKKß, TNFα, TLR4 and HSP70 were determined. Results and conclusions: The banana bract flour showed a high content of phenolic compounds and an antioxidant effect. The in vivo results suggest that the supplementation of a hypercaloric diet with banana bract flour prevented pathological damage by reducing total cholesterol and glucose amounts, which may imply a hepatoprotective effect of this supplement. Thus, using banana bract flour as a supplement can increase the consumption of fibre, antioxidants and bioactive compounds. Novelty and scientific contribution: The development of flour from banana waste and its inclusion in the diet can prevent and/or help treat obesity. In addition, the use of banana bracts can help protect the environment, as they are considered a source of waste by the food industry.
ABSTRACT
Background: Sirtuin 1 (SIRT1) has been associated with longevity and protection against cardiometabolic diseases, but little is known about how it influences human vascular function. Therefore, this study evaluated the effects of SIRT1 activation by resveratrol and energy restriction on vascular reactivity in adults. Methods: A randomized trial allocated 48 healthy adults (24 women and 24 men), aged 55 to 65 years, to resveratrol supplementation or energy restriction for 30 days. Blood lipids, glucose, insulin, C-reactive protein, noradrenaline, SIRT1 (circulating and gene expression), and flow-mediated vasodilation (FMD) and nitrate-mediated vasodilation (NMD) were measured. Results: Both interventions increased circulating SIRT1 (p < 0.001). Pre- and post-tests changes of plasma noradrenaline were significant for both groups (resveratrol: p = 0.037; energy restriction: p = 0.008). Baseline circulating SIRT1 was inversely correlated with noradrenaline (r = -0.508; p < 0.01), and post-treatment circulating SIRT1 was correlated with NMD (r = 0.433; p < 0.01). Circulating SIRT1 was a predictor of FMD in men (p = 0.045), but not in women. SIRT1 was an independent predictor of NMD (p = 0.026) only in the energy restriction group. Conclusions: Energy restriction and resveratrol increased circulating SIRT1 and reduced sympathetic activity similarly in healthy adults. SIRT1 was independently associated with NMD only in the energy restriction group.
Subject(s)
Sirtuin 1 , Stilbenes , Male , Adult , Humans , Female , Resveratrol/pharmacology , Sirtuin 1/metabolism , Glucose/metabolism , Lipids , Insulin , Stilbenes/pharmacologyABSTRACT
The very-low-calorie KD (VLCKD) is characterized by a caloric intake of under 800 kcal/day divided into less than 50 g/day of carbohydrate (13%) and 1 to 1.5 g of protein/kg of body weight (44%) and 43% of fat. This low carbohydrate intake changes the energy source from glucose to ketone bodies. Moreover, clinical trials have consistently shown a beneficial effect of VLCKD in several diseases, such as heart failure, schizophrenia, multiple sclerosis, Parkinson's, and obesity, among others. The gut microbiota has been associated with the metabolic conditions of a person and is regulated by diet interactions; furthermore, it has been shown that the microbiota has a role in body weight homeostasis by regulating metabolism, appetite, and energy. Currently, there is increasing evidence of an association between gut microbiota dysbiosis and the pathophysiology of obesity. In addition, the molecular pathways, the role of metabolites, and how microbiota modulation could be beneficial remain unclear, and more research is needed. The objective of the present article is to contribute with an overview of the impact that VLCKD has on the intestinal microbiota composition of individuals with obesity through a literature review describing the latest research regarding the topic and highlighting which bacteria phyla are associated with obesity and VLCKD.
Subject(s)
Diet, Ketogenic , Gastrointestinal Microbiome , Humans , Weight Loss , Obesity/metabolism , Body Weight , CarbohydratesABSTRACT
Background: Chile's landmark food labeling and advertising policy led to major reductions in sugar purchases. However, it is unclear whether this led to increases in the purchases of nonnutritive sweeteners (NNS). Objectives: The objective of this study was to assess the changes in NNS and caloric-sweetened (CS) products purchased after the law's first phase. Methods: Longitudinal data on food and beverage purchases from 2,381 households collected from January 1, 2015 to December 31, 2017, were linked to nutritional information and categorized into added sweetener groups (unsweetened, NNS-only, CS-only, or NNS with CS). Logistic random-effects models and fixed-effects models were used to compare the percentage of households purchasing products and the mean volume purchased by sweetener category to a counterfactual based on pre-regulation trends. Results: Compared with the counterfactual, the percentage of households purchasing any NNS beverages (NNS-only or NNS with CS) increased by 4.2 percentage points (pp) (95% CI: 2.8, 5.7; P < 0.01). This increase was driven by households purchasing NNS-only beverages (12.1 pp, 95% CI: 10.0, 14.2; P < 0.01). The purchased volume of beverages with any NNS increased by 25.4 mL/person/d (95% CI: 20.1, 30.7; P < 0.01) or 26.5%. Relative to the counterfactual, there were declines of -5.9 pp in households purchasing CS-only beverages (95% CI: -7.0, -4.7; P < 0.01). Regarding the types of sweeteners purchased, we found significant increases in the amounts of sucralose, aspartame, acesulfame K, and steviol glycosides purchased from beverages. Among foods, differences were minimal. Conclusions: The first phase of Chile's law was associated with an increase in the purchases of beverages containing NNS and decreases in beverages containing CS, but virtually no changes in foods.
ABSTRACT
Obesity significantly decreases life expectancy and increases the incidence of age-related dysfunctions, including ß-cell dysregulation leading to inadequate insulin secretion. Here, we show that diluted plasma from obese human donors acutely impairs ß-cell integrity and insulin secretion relative to plasma from lean subjects. Similar results were observed with diluted sera from obese rats fed ad libitum, when compared to sera from lean, calorically restricted, animals. The damaging effects of obese circulating factors on ß-cells occurs in the absence of nutrient overload, and mechanistically involves mitochondrial dysfunction, limiting glucose-supported oxidative phosphorylation and ATP production. We demonstrate that increased levels of adiponectin, as found in lean plasma, are the protective characteristic preserving ß-cell function; indeed, sera from adiponectin knockout mice limits ß-cell metabolic fluxes relative to controls. Furthermore, oxidative phosphorylation and glucose-sensitive insulin secretion, which are completely abrogated in the absence of this hormone, are restored by the presence of adiponectin alone, surprisingly even in the absence of other serological components, for both the insulin-secreting INS1 cell line and primary islets. The addition of adiponectin to cells treated with plasma from obese donors completely restored ß-cell functional integrity, indicating the lack of this hormone was causative of the dysfunction. Overall, our results demonstrate that low circulating adiponectin is a key damaging element for ß-cells, and suggest strong therapeutic potential for the modulation of the adiponectin signaling pathway in the prevention of age-related ß-cell dysfunction.
Subject(s)
Insulin Resistance , Insulin-Secreting Cells , Mice , Humans , Rats , Animals , Adiponectin/metabolism , Insulin Secretion , Insulin/metabolism , Obesity/metabolism , Insulin-Secreting Cells/metabolism , Glucose/metabolism , Insulin Resistance/physiologyABSTRACT
Growth hormone (GH) receptor (GHR) is abundantly expressed in neurons that co-release the agouti-related protein (AgRP) and neuropeptide Y (NPY) in the arcuate nucleus of the hypothalamus (ARH). Since ARHAgRP/NPY neurons regulate several hypothalamic-pituitary-endocrine axes, this neuronal population possibly modulates GH secretion via a negative feedback loop, particularly during food restriction, when ARHAgRP/NPY neurons are highly active. The present study aims to determine the importance of GHR signaling in ARHAgRP/NPY neurons on the pattern of GH secretion in fed and food-deprived male mice. Additionally, we compared the effect of two distinct situations of food deprivation: 16 h of fasting or four days of food restriction (40% of usual food intake). Overnight fasting strongly suppressed both basal and pulsatile GH secretion. Animals lacking GHR in ARHAgRP/NPY neurons (AgRP∆GHR mice) did not exhibit differences in GH secretion either in the fed or fasted state, compared to control mice. In contrast, four days of food restriction increased GH pulse frequency, basal GH secretion, and pulse irregularity/complexity (measured by sample entropy), whereas pulsatile GH secretion was not affected in both control and AgRP∆GHR mice. Hypothalamic Ghrh mRNA levels were unaffected by fasting or food restriction, but Sst expression increased in acutely fasted mice, but decreased after prolonged food restriction in both control and AgRP∆GHR mice. Our findings indicate that short-term fasting and prolonged food restriction differentially affect the pattern of GH secretion, independently of GHR signaling in ARHAgRP/NPY neurons.