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Effects of Dietary Phytoestrogens on Hormones throughout a Human Lifespan: A Review.
Domínguez-López, I, Yago-Aragón, M, Salas-Huetos, A, Tresserra-Rimbau, A, Hurtado-Barroso, S
Nutrients. 2020;12(8)
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Phytoestrogens are polyphenolic molecules with a structural similarity to endogenous human hormones. The main dietary source of these plant secondary metabolites is legumes (particularly soy), and to a lesser extent fruits, vegetables, and cereals. The aim of this study was to synthesize the results obtained by human studies and assess the potential hormone-related health effects of dietary phytoestrogens throughout the human lifespan. Literature shows that: - the impact of phytoestrogens can vary according to the life stage. - soy isoflavones appear not to have any influence on sex and thyroid hormones, bone remodelling and insulin-like growth factor. - although phytoestrogens transfer from maternal blood to the foetus, no effects have been observed in early life. - in later stages of childhood, an increase of androgens and decrease of oestrogens associated with dietary phytoestrogens have been observed in girls and boys, respectively. - in adulthood, endocrine changes arising from phytoestrogen consumption are unclear, although goitrogenic [compounds that interfere with the normal function of the thyroid gland] activity has been observed in men. - in premenopausal women results regarding sex hormones, breast cancer protection and bone remodelling are uncertain. Authors conclude that intake of phytoestrogens does have some physiological effects in humans related to hormone regulation, but like hormones, the benefits depend on the stage of life.
Abstract
Dietary phytoestrogens are bioactive compounds with estrogenic activity. With the growing popularity of plant-based diets, the intake of phytoestrogen-rich legumes (especially soy) and legume-derived foods has increased. Evidence from preclinical studies suggests these compounds may have an effect on hormones and health, although the results of human trials are unclear. The effects of dietary phytoestrogens depend on the exposure (phytoestrogen type, matrix, concentration, and bioavailability), ethnicity, hormone levels (related to age, sex, and physiological condition), and health status of the consumer. In this review, we have summarized the results of human studies on dietary phytoestrogens with the aim of assessing the possible hormone-dependent outcomes and health effects of their consumption throughout a lifespan, focusing on pregnancy, childhood, adulthood, and the premenopausal and postmenopausal stages. In pregnant women, an improvement of insulin metabolism has been reported in only one study. Sex hormone alterations have been found in the late stages of childhood, and goitrogenic effects in children with hypothyroidism. In premenopausal and postmenopausal women, the reported impacts on hormones are inconsistent, although beneficial goitrogenic effects and improved glycemic control and cardiovascular risk markers have been described in postmenopausal individuals. In adult men, different authors report goitrogenic effects and a reduction of insulin in non-alcoholic fatty liver patients. Further carefully designed studies are warranted to better elucidate the impact of phytoestrogen consumption on the endocrine system at different life stages.
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Bridging the Reciprocal Gap between Sleep and Fruit and Vegetable Consumption: A Review of the Evidence, Potential Mechanisms, Implications, and Directions for Future Work.
Noorwali, E, Hardie, L, Cade, J
Nutrients. 2019;11(6)
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Both sleep disruption and a low intake of fruit and vegetables (FV) are associated with higher rates of premature death and chronic disease. This review looked at previous studies in order to determine whether there is a link between sleep and FV consumption. A recent meta-analysis found that shorter sleep duration is consistently associated with low fruit and vegetable intake in children, but in adults the association is less clear. Studies looking at the effect of sleep on FV intake had variable results. Tart cherries and kiwi fruits were the most commonly studied fruits for their effect on sleep measures. Observational studies tended to find that both short- and long-sleepers tend to eat less FV than those that sleep for 7-8 hours. A lot of evidence shows that people who go to sleep later (‘owls’) tend to consume unhealthier diets with lower intakes of FV than people who go to bed earlier (‘larks’). The researchers also looked at potential mechanisms for the association between sleep and FV intake. Polyphenols in FV may influence sleep by increasing neurotransmitters via the gut-brain axis, improving energy metabolism and through alterations in circadian rhythms and the CLOCK genes. Ways in which disrupted sleep may affect FV consumption included changes in hunger hormones, emotional stress and impaired decision making. With further research, interactions between sleep measures and FV consumption may be clarified and potentially reduce the burden of chronic diseases and premature deaths.
Abstract
A substantial burden of disease and mortality globally is attributable to both sleep disruption and low intakes of fruit and vegetable (FV) and there is increasing mechanistic and epidemiological evidence to support a reciprocal relationship between the two. This review provides an overview of experimental and observational studies assessing the relations between sleep and FV consumption from 52 human adult studies. Experimental studies are currently limited and show inconsistent results. Observational studies support a non-linear association with adults sleeping the recommended 7-9 hours/day having the highest intakes of FV. The potential mechanisms linking sleep and FV consumption are highlighted. Disrupted sleep influences FV consumption through homeostatic and non-homeostatic mechanisms. Conversely, FV consumption may influence sleep through polyphenol content via several potential pathways. Few human experimental studies have examined the effects of FV items and their polyphenols on sleep and there is a need for more studies to address this. An appreciation of the relationship between sleep and FV consumption may help optimize sleep and FV consumption and may reduce the burden of chronic diseases. This review provides implications for public health and directions for future work.
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Inverse Association between Organic Food Purchase and Diabetes Mellitus in US Adults.
Sun, Y, Liu, B, Du, Y, Snetselaar, LG, Sun, Q, Hu, FB, Bao, W
Nutrients. 2018;10(12)
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In recent years, accumulating evidence has highlighted the importance of modifiable risk factors, including diet and environmental factors, in the prevention of diabetes. The aim of this study was to examine the association of organic food purchases, as a proxy of organic food consumption, and the frequency of purchasing total and individual organic foods with diabetes prevalence in U.S. adults. The study population consisted of 8199 participants from the 2007–2008 and 2009–2010 cycles of the National Health and Nutrition Examination Survey. Results indicate an inverse association between the purchase of organic foods and diabetes in U.S. adults; more frequent purchase of organic foods was associated with lower odds of diabetes. Moreover, in terms of individual organic food items, the associations were more pronounced for organic milk, eggs, and meats than for organic fruits or vegetables. Authors conclude the further investigation is needed to comprehensively evaluate the long-term effects of organic food consumption on chronic diseases, including diabetes.
Abstract
BACKGROUND The organic food market has grown rapidly worldwide in the past 15 years. However, evidence concerning the health effects of organic foods is scarce. We evaluated the cross-sectional association of organic food purchase, as a proxy of organic food consumption, with diabetes in a nationally representative population. METHODS We included 8199 participants aged ≥20 years from the National Health and Nutrition Examination Survey 2007⁻2008 and 2009⁻2010. Organic food purchase and frequency were ascertained by questionnaires. Diabetes was defined as a self-reported physician diagnosis or a hemoglobin A1c level ≥6.5% or both. We used logistic regression with sample weights to estimate the odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS Individuals who reported purchasing organic foods were less likely to have diabetes compared to those who did not report organic food purchase. After adjustment for age, gender, race/ethnicity, family history of diabetes, socioeconomic status, and dietary and lifestyle factors, the OR of diabetes associated with organic food purchase was 0.80 (95% CI 0.68⁻0.93). The association remained significant after additional adjustment for BMI with OR of 0.80 (0.69⁻0.94). CONCLUSIONS In a nationally representative population, frequent organic food purchase was inversely associated with diabetes prevalence in adults in the United States.
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Probiotic fruit beverages with different polyphenol profiles attenuated early insulin response.
Xu, J, Jönsson, T, Plaza, M, Håkansson, Å, Antonsson, M, Ahrén, IL, Turner, C, Spégel, P, Granfeldt, Y
Nutrition journal. 2018;17(1):34
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Elevated levels of blood glucose after eating, known as postprandial hyperglycaemia, contribute to the development of cardiovascular disease and type 2 diabetes. Postprandial hyperglycaemia is a condition that can be improved through lifestyle and diet modifications. The aim of the study was to investigate and compare the postprandial glycaemic and insulin responses after consuming five different probiotic fruit or vegetable beverages. A secondary aim was to analyse beverages for their polyphenol content and antioxidative capacity. The study is a randomised, controlled, crossover study which included twelve healthy young adults (6 men and 6 women) with a BMI of 24.3 +/- 2.4kg/m2. Results indicate that Bilberry showed the most profound insulin lowering effect, followed by Rose hip. The analysis also showed that Bilberry had the highest values of the total phenolic compounds and flavonols, whereas Mango had the lowest. The highest values of antioxidative capacity were found in Bilberry and Beetroot. Authors conclude that consumption of food products that induce a lower insulin response may enhance insulin sensitivity.
Abstract
BACKGROUND Consumption of polyphenol-rich fruits and vegetables may improve postprandial glucose and insulin levels and hence promote well-being. Previously it has been observed that consumption of bilberry decreases the postprandial insulin demand. The intention with the present study was to compare the impact of different supplements with various polyphenol profiles, on the postprandial glucose and insulin responses in healthy young adults. METHODS In a randomized, controlled, crossover study the postprandial glycemic and insulin responses were observed in eleven healthy adults after intake of five different beverages containing bilberry (European blueberry), blackcurrant, beetroot, mango and rose hip, respectively; all drinks were enriched with the same composition of fermented oatmeal and probiotics. The control was a glucose drink. The profile and content of the polyphenols in the different beverages were determined by HPLC-DAD analysis. The antioxidative capacity of the different beverages were measured by TEAC and DPPH assays. RESULTS Beverages containing bilberry, blackcurrant, mango or rose hip significantly attenuated the early postprandial insulin response (0-90 min), but showed no effect on glucose response. Drinks with bilberry or rose hip reduced the insulin response from the very early phase (0-30 min), and had significantly lower insulin index compared with the control. The efficiency of the bilberry and rose hip to decrease early postprandial insulin responses correlated with higher phenolic contents. CONCLUSIONS Supplements with bilberry, blackcurrant, mango or rose hip in the tested probiotic and oatmeal enriched beverage attenuated early-phase insulin response, but had no effect on the postprandial glycemic response. The improved ability of bilberry and rose hip to lower the very early phase of insulin response seems to be due to a higher phenolic content. TRIAL REGISTRATION The study was retrospectively registered at ClinicalTrials.gov with number NCT03159065 .
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Alcoholic Beverage and Meal Choices for the Prevention of Noncommunicable Diseases: A Randomized Nutrigenomic Trial.
Di Renzo, L, Cioccoloni, G, Sinibaldi Salimei, P, Ceravolo, I, De Lorenzo, A, Gratteri, S
Oxidative medicine and cellular longevity. 2018;2018:5461436
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Noncommunicable diseases (NCDs) are the first cause of death worldwide. Cardiovascular diseases (CVDs) represent the 48% of NCDs, followed by cancer (21%), respiratory chronic diseases (12%), and diabetes (3.5%). The aims of this study were to examine the oxidative status of low-density lipoprotein, and to evaluate gene expression of selected genes belonging to inflammatory and oxidative stress (oxidative stress is a condition that results in an imbalance between the concentrations of pro- and antioxidant species) pathway. The study is a controlled randomised clinical trial based on 55 healthy volunteers in fasting status or in the postprandial time (after a meal), after a Mediterranean or a high-fat meal, with or without alcohol beverages intake. Study results indicate that moderate alcohol consumption has significant health benefits. Genetic regulation due to red wine consumption occurred both with the beverage alone and in combination with a meal. Whereas ethanol had a positive effect on gene oxidation pathway only if combined with an antioxidant meal. Authors conclude that a good dietetic plan, finalised to the reduction of NCDs onset and progression, should consider moderate consumption of alcoholic beverages.
Abstract
BACKGROUND Noncommunicable diseases (NCDs) are the first cause of death worldwide. Mediterranean diet may play a crucial role in the prevention of NCDs, and the presence of wine in this diet could play a positive role on health. METHODS 54 healthy volunteers consumed one of the following beverages: red (RW) or white wine (WW), vodka (VDK), and/or Mediterranean meal (MeDM) and high-fat meal (HFM). RESULTS OxLDL-C changed significantly between baseline versus HFM, MeDM versus HFM, and HFM versus HFM + RW (p < 0.05). Significant upregulation of catalase (CAT) was observed only after RW. Conversely, WW, VDK, RW + MeDM, HF + WW, and HF + VDK determined a significant downregulation of CAT gene. Superoxide dismutase 2 (SOD2) gene expression was upregulated in WW, MeDM + VDK, and RW. Contrariwise, HFM + VDK determined a downregulation of its expression. RW, RW + MeDM, and RW + HFM caused the upregulation of glutathione peroxidase-1 (GPX1). CONCLUSIONS Our results suggest that the association of low/moderate intake of alcohol beverages, with nutraceutical-proven effectiveness, and ethanol, in association with a Mediterranean diet, could determine a reduction of atherosclerosis risk onset through a positive modulation of antioxidant gene expression helping in the prevention of inflammatory and oxidative damages.
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Olive Polyphenols and the Metabolic Syndrome.
Saibandith, B, Spencer, JPE, Rowland, IR, Commane, DM
Molecules (Basel, Switzerland). 2017;22(7)
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Up to 25% of the world’s population has metabolic syndrome (MetS), characterised by a combination of high blood pressure, high blood sugar, obesity and abnormal levels of fats in the blood. People with MetS have an increased risk of developing type 2 diabetes and heart disease. The development of MetS is related to modifiable diet and lifestyle factors. This review presents evidence from previous studies investigating the relationship between consumption of olive products, and aspects of MetS, and discusses potential mechanisms linking olive consumption to improvements in markers of health. The authors found good evidence from previous human studies showing that the consumption of olives and olive oil lowers blood pressure in people diagnosed with high blood pressure. There is also good evidence that olives and olive oil can improve blood glucose levels in those with prediabetes and improve markers of lipid peroxidation. There is limited, but promising evidence for effects on dyslipidaemia and the inhibition of weight gain. Studies that used extra virgin olive oil (EVOO) used doses of up to 50g per day, well above the amount that is consumed habitually in most diets. Further evidence is needed to confirm the mechanisms and benefits of olive polyphenols, but the authors suggest that they may explain some of the metabolic benefits associated with a Mediterranean diet.
Abstract
Here, the effects of consuming polyphenol-rich olive products, including olive leaves, their crude extract, and extra virgin olive oil, on aspects of the metabolic syndrome are reviewed. We have sought to summarize the available scientific evidence from dietary intervention trials demonstrating a role for these phytochemicals in ameliorating aberrant glucose metabolism, high blood pressure and elevated blood lipids, and we discuss the potential mechanisms underpinning these observations. Searches for relevant literature published in English were conducted via PubMed and Science Direct. Based on published dietary intervention studies, there is convincing evidence to show that olive polyphenols, independently of olive lipids, reduce risk factors for metabolic syndrome, in particular by improving blood sugar and blood pressure control, and in reducing low density lipoprotein oxidation. There is more limited evidence to suggest that the consumption of olive polyphenols or related products can reduce body weight and visceral fat or impede weight gain, and similarly there are some limited data suggesting improved lipid profiles. There is some mechanistic data to support observations made in human volunteers, but further work is needed in this area. The consumption of olive polyphenols within the context of a healthy pattern of food intake may, in part, explain the reduced risk of metabolic disease associated with adherence to the Mediterranean diet.
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Combined epigallocatechin-3-gallate and resveratrol supplementation for 12 wk increases mitochondrial capacity and fat oxidation, but not insulin sensitivity, in obese humans: a randomized controlled trial.
Most, J, Timmers, S, Warnke, I, Jocken, JW, van Boekschoten, M, de Groot, P, Bendik, I, Schrauwen, P, Goossens, GH, Blaak, EE
The American journal of clinical nutrition. 2016;104(1):215-27
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The prevalence of obesity and related chronic diseases is continuously increasing. Insulin resistance is a major risk factor for the progression of obesity toward chronic metabolic diseases, including cardiovascular disease and type 2 diabetes. Polyphenols were identified as dietary ingredients with antioxidant properties decades ago. Epigallocatechin-3-gallate (EGCG), which is most abundant in green tea, and resveratrol (RS), which is present in grape skins, have been implicated in the prevention of body weight gain and improvements in markers of insulin sensitivity in human and animal studies. The aim of this randomised control study was to investigate the longer-term effect of EGCG and RES (EGCG+RES) supplementation on metabolic profile, mitochondrial capacity, fat oxidation, lipolysis, and tissue-specific insulin sensitivity. 38 overweight and obese men and women received supplementation with either EGCG+RES (282 and 80 mg/d, respectively) or a placebo for 12 weeks. Before and after the intervention, oxidative capacity, lipid metabolism and insulin sensitivity were measured. EGCG+RES supplementation did not affect the fasting plasma metabolic profile. Although whole-body fat mass was not affected, visceral adipose tissue mass decreased after the intervention compared with placebo. EGCG+RES supplementation significantly increased oxidative capacity in muscle fibres. Fat oxidation and energy expenditure were not significantly affected by EGCG+RES. Finally, EGCG+RES had no effect on insulin-stimulated glucose disposal, suppression of endogenous glucose production, or lipolysis. The authors concluded that 12 weeks of EGCG+RES supplementation increased mitochondrial capacity and stimulated fat oxidation compared with placebo, and this may improve physical condition and play a role in the prevention of weight gain and worsening of insulin resistance in the long term.
Expert Review
Conflicts of interest:
None
Take Home Message:
- 12 wks of EGCG+RES intake increased skeletal muscle oxidative capacity as well as upregulating mitochondrial pathways, which may translate into an improved metabolic risk profile over time because greater mitochondrial capacity has been associated with higher insulin sensitivity in other studies
- The fat oxidation alterations in those taking the active ingredients vs. the placebo group suggests that this intervention could lead to metabolic adaptation towards lipids instead of CHOs as a fuel source, over time.
- EGCG+RES intake attenuated the increase in plasma triacylglycerol levels during the HFMM test, while the levels were significantly increased in the placebo group after 12 wks. This suggests that the intervention may provide positive support for individuals with high triacylglcerol (triglyceride) levels
- The ratio of total cholesterol to HDL cholesterol tended to decrease after EGCG+RES supplementation but not after placebo. Increased total & HDL cholesterol marker for myocardial infarction risk, so this intervention could help with persons who have disordered cholesterol values, and perhaps contribute to reducing their MI risk over time.
Evidence Category:
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A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
- This randomised controlled trial investigated the effect of 12-wk supplementation of combined epigallocatechin-3-gallate and resveratrol (EGCG+RES) on metabolic profile, mitochondrial capacity, fat oxidation, lipolysis, and insulin sensitivity.
- 38 overweight and obese subjects (active ingredient cohort n = 18; placebo n = 20) received 282 mg/d EGCG and 80 mg/d resveratrol; one capsule of each was taken at breakfast and dinner. Subjects were medically screened 10 times in total, including: 3 times before starting supplementation, 3 times during the supplementation period, and 3 in the last week of supplementation.
- EGCG capsules contained 94% epigallocatechin-3-gallate (141 mg/capsule) and resveratrol capsules contained 20% trans-resveratrol (40 mg trans-resveratrol in Polygonum cuspidatum extract/capsule).
- Medical screening included skeletal muscle biopsies (Vastus lateralis), with various tests done to measure oxidative capacity, X-ray absorptionmetry, a high-fat mixed meal (HFMM) test, and an insulin test via hyperinsulinemic-euglycemic clamp; meal intake before screening was standardised.
- Blood probes were also taken, and subjects completed food records; exact kcals per macronutrient were calculated.
Clinical practice applications:
The results of the study, which relate to clinical practice, highlight:
- 12 weeks of ECGC+RES supplementation increased mitochondrial capacity.
- EGCG+RES increased skeletal muscle oxidative capacity as well as protein expression of OxPhos complexes in skeletal muscle.
- EGCG+RES supplementation significantly affected fasting substrate oxidation, whereas fat oxidation declined in the placebo group; this suggests that it could help to improve fat metabolism.
- 12 weeks of ECGC+RES supplementation preserved fasting and postprandial fat oxidation compared with placebo.
- Plasma triacylglycerol levels were not significantly increased in the EGCG+RES cohort on being given an HFMM test after 12 wks, whereas they went up in the placebo group, indicating that this intervention preserved fasting and post-prandial fat oxidation.
- EGCG+RES group tended to decrease visceral adipose tissue mass by ~11% vs. placebo,
- These findings suggest that combined ECGC+RES supplementation might support mitochondrial function and weight loss/insulin sensitivity over a longer period of time
Considerations for future research:
- The EGCG+RES supplementation had no effect on postprandial glucose, insulin and FFA concentrations or local interstitial glucose and glycerol concentrations. Altering the study parameters in the future might identify changes of these markers.
- There was a tendency toward visceral adipose tissue mass decrease that was not considered significant, but altering dosage and length of time of a similar study might result in a more notable outcome related to weight loss, which was a targeted endpoint
- The combined supplements were not found to affect energy expenditure, contrary to a previous study by the same team, which was for a much shorter time period. It would be interesting to identify why this was.
- Complex and numerous gene set enrichment analyses were performed indicating that the most upregulated pathways after EGCG+RES supplementation were related to the Krebs cycle and electron transport chain, whereas pathways related to CHO metabolism were upregulated in the placebo group. This was taken to indicate that the increased mitochondrial capacity after EGCG +RES supplementation is accompanied by changes at the transcriptional and translational levels; further follow-up of this would be useful to know what clinical impact this has longer term
Abstract
BACKGROUND The obese insulin-resistant state is characterized by impairments in lipid metabolism. We previously showed that 3-d supplementation of combined epigallocatechin-3-gallate and resveratrol (EGCG+RES) increased energy expenditure and improved the capacity to switch from fat toward carbohydrate oxidation with a high-fat mixed meal (HFMM) test in men. OBJECTIVE The present study aimed to investigate the longer-term effect of EGCG+RES supplementation on metabolic profile, mitochondrial capacity, fat oxidation, lipolysis, and tissue-specific insulin sensitivity. DESIGN In this randomized double-blind study, 38 overweight and obese subjects [18 men; aged 38 ± 2 y; body mass index (kg/m(2)): 29.7 ± 0.5] received either EGCG+RES (282 and 80 mg/d, respectively) or placebo for 12 wk. Before and after the intervention, oxidative capacity and gene expression were assessed in skeletal muscle. Fasting and postprandial (HFMM) lipid metabolism was assessed by using indirect calorimetry, blood sampling, and microdialysis. Tissue-specific insulin sensitivity was assessed by a hyperinsulinemic-euglycemic clamp with [6,6-(2)H2]-glucose infusion. RESULTS EGCG+RES supplementation did not affect the fasting plasma metabolic profile. Although whole-body fat mass was not affected, visceral adipose tissue mass tended to decrease after the intervention compared with placebo (P-time × treatment = 0.09). EGCG+RES supplementation significantly increased oxidative capacity in permeabilized muscle fibers (P-time × treatment < 0.05, P-EGCG+RES < 0.05). Moreover, EGCG+RES reduced fasting (P-time × treatment = 0.03) and postprandial respiratory quotient (P-time × treatment = 0.01) compared with placebo. Fasting and postprandial fat oxidation was not significantly affected by EGCG+RES (P-EGCG+RES = 0.46 and 0.38, respectively) but declined after placebo (P-placebo = 0.05 and 0.03, respectively). Energy expenditure was not altered (P-time × treatment = 0.96). Furthermore, EGCG+RES supplementation attenuated the increase in plasma triacylglycerol concentrations during the HFMM test that was observed after placebo (P-time × treatment = 0.04, P-placebo = 0.01). Finally, EGCG+RES had no effect on insulin-stimulated glucose disposal, suppression of endogenous glucose production, or lipolysis. CONCLUSION Twelve weeks of EGCG+RES supplementation increased mitochondrial capacity and stimulated fat oxidation compared with placebo, but this did not translate into increased tissue-specific insulin sensitivity in overweight and obese subjects. This trial was registered at clinicaltrials.gov as NCT02381145.