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Carbohydrate metabolism and de novo lipogenesis in human obesity: Insulin resistance drives hepatic de novo lipogenesis in nonalcoholic fatty liver disease

The pentose-phosphate pathway is active in adipose tissue of healthy humans, consistent with an active role of this tissue in de novo lipogenesis.

Ethan Walker
Thursday, August 9, 2018
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  • The latter closely correspond to serum FFA profiles in humans, at least with regard to Cn7 and other DNL-derived fatty acids 44 ,

  • On each occasion, they underwent a metabolic study during which their energy expenditure and net substrate oxidation rates indirect calorimetrycarbohyydrate the fractional activity of the pentose-phosphate pathway in subcutaneous adipose tissue subcutaneous microdialysis with 1,6 13 C2,6,6 2 H2 glucose were assessed before and after administration of glucose. The pentose-phosphate pathway is active in adipose tissue of healthy humans, consistent with an active role of this tissue in de novo lipogenesis.

  • Effects of enteral carbohydrates on de novo lipogenesis in critically ill patients.

  • Results: Carbohydrate overfeeding increased basal and postglucose energy expenditure and net carbohydrate oxidation.

  • Louis, MissouriUSA. Am J Clin Nutr.

Publication types

Consequently, both carbohydrates and lipids are potential sources of these stored fats. Publication types Review. Basic equations are provided in this review to facilitate the interpretation of the different subcomponents of fat balance endogenous vs exogenous under different nutritional circumstances. The role of DNL and its importance in health and disease remain to be further clarified, in particular the putative effect of DNL on the control of energy intake and energy expenditure, as well as the occurrence of DNL in other tissues such as in myocytes in addition to hepatocytes and adipocytes. Publication types Review.

Publication types Review. Three issues, which are still controversial today, will ,ipogenesis addressed: 1 Is the increase of fat mass induced by CHO overfeeding explained by DNL only, or by decreased endogenous fat oxidation, or both? Adipose tissue biopsies were obtained at the end of on experiments to monitor mRNAs of key lipogenic enzymes. In case of positive balance, lipids stored in adipose tissue can originate from dietary exogenous lipids or from nonlipid precursors, mainly from carbohydrates CHOs but also from ethanol, through a process known as de novo lipogenesis DNL. This is possible mostly under laboratory conditions and not yet in free-living conditions. Research methods and procedures: Nine healthy lean volunteers five men and four women were studied after 4 days of either isocaloric feeding or carbohydrate overfeeding. Many factors affect the onset of obesity including satiety control, reduced levels of physical exercise as well as hormonal and genetic parameters which influence the metabolic pathways leading to the net accumulation of triacylglycerol TAG.

Although the numerous factors mostly exogenous influencing DNL have been studied, in particular the effect of CHO overfeeding, there is little information on the rate of DNL in habitual conditions of life, that is, large day-to-day fluctuations of CHO intakes, different types of CHO ingested with different glycemic indexes, alcohol combined with excess CHO intakes, etc. Abstract Many factors affect the onset of obesity including satiety control, reduced levels of physical exercise as well as hormonal and genetic parameters which influence the metabolic pathways leading to the net accumulation of triacylglycerol TAG. Abstract The measurement of fat balance fat input minus fat output involves the accurate estimation of both metabolizable fat intake and total fat oxidation. This is possible mostly under laboratory conditions and not yet in free-living conditions. Many studies have been carried out using a variety of differing experimental protocols on healthy, obese or diabetic humans and animals in positive or neutral energy balance to establish the underlying molecular basis for obesity particularly in humans. On each occasion, they underwent a metabolic study during which their energy expenditure and net substrate oxidation rates indirect calorimetryand the fractional activity of the pentose-phosphate pathway in subcutaneous adipose tissue subcutaneous microdialysis with 1,6 13 C2,6,6 2 H2 glucose were assessed before and after administration of glucose. The role of DNL and its importance in health and disease remain to be further clarified, in particular the putative effect of DNL on the control of energy intake and energy expenditure, as well as the occurrence of DNL in other tissues such as in myocytes in addition to hepatocytes and adipocytes.

Publication types Review. An increase in mRNAs coding for key lipogenic enzymes suggests that de novo lipogenesis occurred, at least in part, in adipose tissue. Many studies have been carried out using a variety of differing experimental protocols on carbohydrate metabolism and de novo lipogenesis in human obesity, obese or diabetic humans and animals in positive or neutral energy balance to establish the underlying molecular basis for obesity particularly in humans. Abstract Many factors affect the onset of obesity including satiety control, reduced levels of physical exercise as well as hormonal and genetic parameters which influence the metabolic pathways leading to the net accumulation of triacylglycerol TAG. From these observations it should be possible to determine the relevance of the hypothesis to humans and to speculate how these aspects of metabolism may impact the risk of developing related diseases such as coronary heart disease, Type 2 diabetes and certain forms of cancer.

On each occasion, they underwent a metabolic study during carbohydrate metabolism and de novo lipogenesis in human obesity their energy expenditure and net substrate oxidation rates indirect calorimetryand the fractional activity of the pentose-phosphate pathway in subcutaneous adipose tissue subcutaneous microdialysis with 1,6 13 C2,6,6 2 H2 glucose were assessed before and carbobydrate administration of glucose. Csrbohydrate factors affect the onset of obesity including satiety control, reduced levels of physical exercise as well as hormonal and genetic parameters which influence the metabolic pathways leading to the net accumulation of triacylglycerol TAG. Consequently, both carbohydrates and lipids are potential sources of these stored fats. The predominant fatty acid of human adipose tissue TAGs is oleic acid, reflecting primarily the composition of the diet but also the product of de novo lipogenesis. Research methods and procedures: Nine healthy lean volunteers five men and four women were studied after 4 days of either isocaloric feeding or carbohydrate overfeeding. Recent studies have demonstrated that acute CHO overfeeding influences adipose tissue lipogenic gene expression and that CHO may stimulate DNL in skeletal muscles, at least in vitro. This is possible mostly under laboratory conditions and not yet in free-living conditions.

Publication types Review. Many studies have been carried out using a variety of differing experimental protocols on healthy, obese or diabetic humans and animals in positive or neutral energy balance to establish the underlying molecular basis for obesity particularly in humans. Substances Dietary Carbohydrates Fats Lipids. The measurement of fat balance fat input minus fat output involves the accurate estimation of both metabolizable fat intake and total fat oxidation.

Evaluating Dietary Fat and DNL

Many studies have been carried out using a variety of differing experimental protocols on healthy, obese or diabetic humans and animals in positive or neutral energy balance to establish the underlying molecular basis for obesity particularly in humans. Basic equations are provided in this review to facilitate the interpretation of the different subcomponents of fat balance endogenous vs exogenous under different nutritional circumstances. On each occasion, they underwent a metabolic study during which their energy expenditure and net substrate oxidation rates indirect calorimetryand the fractional activity of the pentose-phosphate pathway in subcutaneous adipose tissue subcutaneous microdialysis with 1,6 13 C2,6,6 2 H2 glucose were assessed before and after administration of glucose. Recent studies have demonstrated that acute CHO overfeeding influences adipose tissue lipogenic gene expression and that CHO may stimulate DNL in skeletal muscles, at least in vitro.

  • Figure 3: SAT lipogenic gene expression in obese compared with non-obese subjects. Our data suggest that daily hour increases in plasma insulin and glucose concentrations associated with insulin-resistant glucose metabolism contribute to the stimulation of hepatic DNL.

  • Basic equations are provided in this review to facilitate the interpretation of the different subcomponents of fat balance endogenous vs exogenous under different nutritional circumstances.

  • Find articles by Yoshino, M. Macrophage inhibitory factor, plasminogen activator inhibitor-1, other acute phase proteins, and inflammatory mediators normalize as a result of weight loss in morbidly obese subjects treated with gastric restrictive surgery.

  • Recent studies have demonstrated that acute CHO overfeeding influences adipose tissue lipogenic gene expression and that CHO may stimulate DNL in skeletal muscles, at least in vitro. Whole body net de novo lipogenesis after glucose loading was markedly increased at the expense of glycogen synthesis.

  • DNL in adipose tissue TGs was very minimal and did not differ between groups: 1.

Likewise, in the fed state, DNL is also determined by the type of simple sugar consumed. Subjects were recruited between April and November via the Volunteers for Health database at the Washington University School of Medicine and via local postings. DNL in adipose tissue TGs was very minimal and did not differ between groups: 1. Nonsignificant terms were hierarchically-backward eliminated as suggested by Kleinbaum and Klein

Abstract Objective: To evaluate the effect of a 4-day carbohydrate overfeeding on whole body net de novo lipogenesis and on markers of de novo lipogenesis in lippogenesis adipose tissue of carbohydrate metabolism and de novo lipogenesis in human obesity lean humans. Adipose tissue biopsies were obtained at the end of the experiments to monitor mRNAs of key lipogenic snd. The hypothesis focuses on the central role of stearoyl-CoA desaturase SCD and its inhibition by polyunsaturated fatty acids PUFAs acting via transcription factors based upon data obtained from both animal and human studies. The measurement of fat balance fat input minus fat output involves the accurate estimation of both metabolizable fat intake and total fat oxidation. Results: Carbohydrate overfeeding increased basal and postglucose energy expenditure and net carbohydrate oxidation. Carbohydrate overfeeding also increased mRNA levels for the key lipogenic enzymes sterol regulatory element-binding protein-1c, acetyl-CoA carboxylase, and fatty acid synthase. Many studies have been carried out using a variety of differing experimental protocols on healthy, obese or diabetic humans and animals in positive or neutral energy balance to establish the underlying molecular basis for obesity particularly in humans.

Historical Perspective for a Role of Sugar in Obesity

Sign up for email alerts. J Am Heart Assoc. Proposed molecular mechanisms of DNL-induced lipotoxicity are, for example, exaggerated synthesis of insulin resistance-inducing ceramides from palmitate C ref. Find articles by Beals, J.

Publication types Review. Although the numerous factors mostly exogenous influencing DNL have onvo studied, in particular the effect of CHO overfeeding, there is little information on the rate lipogenesiss DNL in habitual conditions of life, that is, large day-to-day fluctuations of CHO intakes, different types of CHO ingested with different glycemic indexes, alcohol combined with excess CHO intakes, etc. Three issues, which are still controversial today, will be addressed: 1 Is the increase of fat mass induced by CHO overfeeding explained by DNL only, or by decreased endogenous fat oxidation, or both? The predominant fatty acid of human adipose tissue TAGs is oleic acid, reflecting primarily the composition of the diet but also the product of de novo lipogenesis. Results: Carbohydrate overfeeding increased basal and postglucose energy expenditure and net carbohydrate oxidation. Abstract Many factors affect the onset of obesity including satiety control, reduced levels of physical exercise as well as hormonal and genetic parameters which influence the metabolic pathways leading to the net accumulation of triacylglycerol TAG.

Substances Dietary Carbohydrates Fats Lipids. Abstract Objective: To evaluate the effect of a 4-day carbohydrate overfeeding on whole body net de novo lipogenesis and on markers of de novo lipogenesis in subcutaneous adipose tissue of healthy lean humans. Three issues, which are still controversial today, will be addressed: 1 Is the increase of fat mass induced by CHO overfeeding explained by DNL only, or by decreased endogenous fat oxidation, or both? Discussion: Carbohydrate overfeeding markedly increased net de novo lipogenesis at the expense of glycogen synthesis. Consequently, both carbohydrates and lipids are potential sources of these stored fats.

Publication types

Bariatric surgery is a clinical intervention that often leads to marked weight loss and an improvement of metabolic health with the potential to cure T2D. Second, we avoided overestimating the potential contribution of fatty acids synthesized de novo in adipose tissue that could have been released into the circulation and incorporated into VLDL-TGs in the liver 14 — You have full access to this article via your institution. A glucose-responsive transcription factor that regulates carbohydrate metabolism in the liver. Lipids 43—

Publication types Review. Three issues, which are still controversial today, will be addressed: 1 Is the increase of fat mass induced by Humna carbohydrate metabolism and de novo lipogenesis in human obesity explained by DNL only, or by decreased endogenous fat oxidation, or both? Research methods and procedures: Nine healthy lean volunteers five men and four women were studied after 4 days of either isocaloric feeding or carbohydrate overfeeding. The measurement of fat balance fat input minus fat output involves the accurate estimation of both metabolizable fat intake and total fat oxidation. Basic equations are provided in this review to facilitate the interpretation of the different subcomponents of fat balance endogenous vs exogenous under different nutritional circumstances. Results: Carbohydrate overfeeding increased basal and postglucose energy expenditure and net carbohydrate oxidation.

One subject withdrew from the study because of an inability to lose weight; data from 6 subjects are reported here. Since that time, studies have demonstrated that high-sugar diets and hepatic DNL can increase the risk for elevated blood lipid levels, cardiovascular disease, NAFLD, insulin resistance, and type 2 diabetes mellitis. Hepatic DNL was assessed using the deuterated water method corrected for the potential confounding contribution of adipose tissue DNL. Early and longer term effects of gastric bypass surgery on tissue-specific insulin sensitivity and beta cell function in morbidly obese patients with and without type 2 diabetes. Fructose and liver function—is this behind nonalcoholic liver disease? Weight loss has profound effects on IHTG content.

Western blot analysis Protein extraction and western blot analysis were performed as described Cell— Effects of enteral carbohydrates on de novo lipogenesis in critically ill patients. A large proportion of people with obesity or NAFLD have insulin resistance, 31 and most people with insulin resistance have increased liver fat concentration.

  • Figure 1 Relationships among hepatic DNL and metabolic characteristics. The supernatant was then collected while carefully avoiding the lipid layer on top and protein concentration was measured with a BCA protein quantification kit Thermo Scientific.

  • From these observations it farbohydrate be possible to determine the relevance of the hypothesis to humans and to speculate how these aspects of metabolism may impact the risk of developing related diseases such as coronary heart disease, Type 2 diabetes and certain forms of cancer. Carbohydrate overfeeding also increased mRNA levels for the key lipogenic enzymes sterol regulatory element-binding protein-1c, acetyl-CoA carboxylase, and fatty acid synthase.

  • Enoch, H. The effect of dietary carbohydrate on genes for fatty acid synthase and inflammatory cytokines in adipose tissues from lean and obese subjects.

  • On each occasion, they underwent a metabolic study during which their energy expenditure and net substrate oxidation rates indirect calorimetryand the fractional activity of the pentose-phosphate pathway in subcutaneous adipose tissue subcutaneous microdialysis with 1,6 13 C2,6,6 2 H2 glucose were assessed before and after administration of glucose.

  • On the basis of anf interindividual variability in hepatic DNL, assessed using the D 2 O technique in individuals with obesity with normal IHTG content and in those with obesity and NAFLD, and reported by others previously 14and on the basis of whole-body insulin sensitivity, assessed as the glucose Rd during a HECP we reported previously 61we estimated that 15 to 25 subjects per group would be needed to detect between-groups differences in hepatic DNL of 7. Jr, Zechne,r, R.

  • This is lipovenesis mostly under laboratory conditions and not yet in free-living conditions. Many studies have been carried out using a variety of differing experimental protocols on healthy, obese or diabetic humans and animals in positive or neutral energy balance to establish the underlying molecular basis for obesity particularly in humans.

The role of DNL and carbohyxrate importance in health and disease remain to be further clarified, in particular the putative effect of DNL on the control of energy intake and energy expenditure, as well as the occurrence of DNL in other tissues such as in myocytes in addition to hepatocytes and adipocytes. Adipose tissue biopsies were obtained at the end of the experiments to monitor mRNAs of key lipogenic enzymes. Consequently, both carbohydrates and lipids are potential sources of these stored fats. Recent studies have demonstrated that acute CHO overfeeding influences adipose tissue lipogenic gene expression and that CHO may stimulate DNL in skeletal muscles, at least in vitro. In case of positive balance, lipids stored in adipose tissue can originate from dietary exogenous lipids or from nonlipid precursors, mainly from carbohydrates CHOs but also from ethanol, through a process known as de novo lipogenesis DNL.

ALSO READ: World Obesity Chart 2011 Gmc

For detailed analyses, gender-matched subgroups including non-obese non-diabetic subjects controlsobese non-diabetic subjects obese and obese subjects with T2D obese-diabetic were selected from the total cohort. Adipocytes as regulators of energy balance and glucose homeostasis. Article Google Scholar 37 Roberts, R. Ann Rev Nutr. Y Schutz.

Find articles by Nyangau, E. In contrast to Cn7, we detected a strong decrease in obese and obese-diabetic subjects for stearate C Fig. Studies of the substrate specificity, enzyme-substrate interactions, and the function of lipid. Exclusion criteria were type 1 diabetes and acute inflammatory disease. Coca-Cola Journey website.

Introduction

Consequently, both carbohydrates and lipids are potential sources of these stored fats. Abstract The measurement of fat balance fat carbohyydrate minus fat output involves the accurate estimation of both metabolizable fat intake and total fat oxidation. Many studies have lbesity carried out using a variety of differing experimental protocols on healthy, obese or diabetic humans and animals in positive or neutral energy balance to establish the underlying molecular basis for obesity particularly in humans. Abstract Objective: To evaluate the effect of a 4-day carbohydrate overfeeding on whole body net de novo lipogenesis and on markers of de novo lipogenesis in subcutaneous adipose tissue of healthy lean humans. The role of DNL and its importance in health and disease remain to be further clarified, in particular the putative effect of DNL on the control of energy intake and energy expenditure, as well as the occurrence of DNL in other tissues such as in myocytes in addition to hepatocytes and adipocytes.

  • Markers of de novo lipogenesis in adipose tissue: associations with small adipocytes and insulin sensitivity in humans.

  • Whole body net de novo lipogenesis after glucose loading was markedly increased at the expense of glycogen synthesis.

  • How important is the relative balance of fat and carbohydrate as sources of energy in relation to health? Fructose-induced in vivo insulin resistance and elevated plasma triglyceride levels in rats.

  • Dixon, J.

Abstract Objective: To evaluate the effect human obesity a 4-day carbohydrate overfeeding on whole body net de novo lipogenesis and on markers of de novo lipogenesis in subcutaneous adipose tissue of healthy lean humans. In case of positive balance, lipids stored in adipose tissue can originate from dietary exogenous lipids or from nonlipid precursors, mainly from carbohydrates CHOs but also from ethanol, through a process known as de novo lipogenesis DNL. Publication types Review. On each occasion, they underwent a metabolic study during which their energy expenditure and net substrate oxidation rates indirect calorimetryand the fractional activity of the pentose-phosphate pathway in subcutaneous adipose tissue subcutaneous microdialysis with 1,6 13 C2,6,6 2 H2 glucose were assessed before and after administration of glucose. An increase in mRNAs coding for key lipogenic enzymes suggests that de novo lipogenesis occurred, at least in part, in adipose tissue. Consequently, both carbohydrates and lipids are potential sources of these stored fats.

Epidemiologic studies suggest a link between excess sugar consumption and obesity, fatty liver disease, metabolic syndrome, and type 2 diabetes mellitus. Effect of a high-fructose weight-maintaining diet on lipogenesis and liver fat. Hepatic glucose control can be restored by restricting added sucrose and fructose in one's diet. Download references. Lipid Res.

Volume In an outpatient study 13 in obese Latino and African American children with features of metabolic syndrome eg, elevated triglycerides, insulin resistance, carbohydrate metabolism and de novo lipogenesis in human obesity who reported high levels of sugar intake, 9 days of fructose restriction with isocaloric substitution of complex carbohydrates resulted in reductions in fasting glucose and insulin levels, improved glucose tolerance, 41 and less atherogenic lipoprotein profiles. Open bars and symbols are females; RPearson correlation coefficient. Advanced Search. This suggests increased SCD activity in adipose tissue of obese individuals and can explain the most prominent fatty acid changes we observed in obese subjects, namely a decrease in C and an increase in Cn9 Fig.

  • Cao, H. Latest Most Read Most Cited Vitamin C and scar strength: analysis of a historical trial and implications for collagen-related pathologies.

  • Publication types Research Support, Non-U.

  • None of the cancer patients exhibited signs of metastases or reported excessive, unintended recent weight loss.

Consequently, both carbohydrates and lipids are potential sources of these stored fats. An increase in mRNAs coding for key lipogenic enzymes suggests that de novo lipogenesis occurred, at least in part, in adipose tissue. The role of Complications of obesity medscape cardiology and its importance in health and disease remain to be further clarified, in particular the putative effect of DNL on the control of energy intake and energy expenditure, as well as the occurrence of DNL in other tissues such as in myocytes in addition to hepatocytes and adipocytes. The pentose-phosphate pathway is active in adipose tissue of healthy humans, consistent with an active role of this tissue in de novo lipogenesis. Many studies have been carried out using a variety of differing experimental protocols on healthy, obese or diabetic humans and animals in positive or neutral energy balance to establish the underlying molecular basis for obesity particularly in humans.

Identification of a lipokine, a lipid hormone linking adipose tissue to systemic metabolism. To what extent Cn7 is an insulin-sensitizing factor in humans, as it is in mice 467is a matter of ongoing debate 434445 and cannot be directly inferred from our data. J Am Heart Assoc. Studies conducted in primary hepatocytes and in rodent models of obesity and diabetes support the notion of selective pathway—specific insulin resistance in the liver 31 — Article Google Scholar 16 Faraj, M. Weight loss decreased IHTG content, in conjunction with a decrease in hepatic DNL and hour plasma glucose and insulin concentrations. Fatty acid composition in total lipid extracts of VAT was determined by gas chromatography, as described previously

Abstract Many factors affect the onset of obesity including satiety control, reduced levels of physical exercise as well as hormonal and genetic parameters which influence the metabolic pathways leading to the net accumulation of triacylglycerol TAG. Three issues, which are still controversial today, will be addressed: 1 Is the increase of fat mass induced by CHO overfeeding explained by DNL only, or by decreased endogenous fat oxidation, or both? Research methods and procedures: Nine healthy lean volunteers five men and four women were studied after 4 days of either isocaloric feeding or carbohydrate overfeeding.

Oxford Lipogenesix Press is a department of the University of Oxford. Effects of a low-fat, high-carbohydrate diet on VLDL-triglyceride assembly, production, and clearance. These findings support the notion of a dissociation between insulin action on hepatic glucose and lipid metabolism in individuals with NAFLD, manifested by insulin-resistant hepatic glucose metabolism but insulin-sensitive hepatic lipogenesis. One subject withdrew from the study because of an inability to lose weight; data from 6 subjects are reported here. At hours, a primed 8.

Research methods and procedures: Nine lipovenesis lean volunteers five men and four women were studied after 4 days of either isocaloric feeding hyman carbohydrate overfeeding. Publication types Review. Adipose tissue biopsies were obtained at the carbohydrate metabolism and de novo lipogenesis in human obesity of the experiments to monitor mRNAs of key lipogenic enzymes. Abstract Objective: To evaluate the effect of a 4-day carbohydrate overfeeding on whole body net de novo lipogenesis and on markers of de novo lipogenesis in subcutaneous adipose tissue of healthy lean humans. On each occasion, they underwent a metabolic study during which their energy expenditure and net substrate oxidation rates indirect calorimetryand the fractional activity of the pentose-phosphate pathway in subcutaneous adipose tissue subcutaneous microdialysis with 1,6 13 C2,6,6 2 H2 glucose were assessed before and after administration of glucose. Publication types Research Support, Non-U. The measurement of fat balance fat input minus fat output involves the accurate estimation of both metabolizable fat intake and total fat oxidation.

Research methods and procedures: Nine healthy lean volunteers five men and four women were studied after 4 days of either isocaloric feeding or carbohydrate overfeeding. Discussion: Carbohydrate overfeeding markedly increased net de novo lipogenesis at the expense of glycogen synthesis. Consequently, both carbohydrates and lipids are potential sources of these stored fats. Abstract Objective: To evaluate the effect of a 4-day carbohydrate overfeeding on whole body net de novo lipogenesis and on markers of de novo lipogenesis in subcutaneous adipose tissue of healthy lean humans. On each occasion, they underwent a metabolic study during which their energy expenditure and net substrate oxidation rates indirect calorimetryand the fractional activity of the pentose-phosphate pathway in subcutaneous adipose tissue subcutaneous microdialysis with 1,6 13 C2,6,6 2 H2 glucose were assessed before and after administration of glucose.

  • Louis, Missouri, USA.

  • Many factors affect the onset of obesity including satiety control, reduced levels of physical exercise as well as hormonal and genetic parameters which influence the metabolic pathways leading to the net accumulation of triacylglycerol TAG.

  • Accessed June 5, Logarithmic regression analysis was used to determine the lines of best fit to the data.

  • Find articles by Chondronikola, M. After baseline testing was completed, 7 subjects in the obese-NAFLD group participated in a weight loss program supervised by our study dietitian and behavioral psychologist, involving weekly individual dietary and behavioral education sessions with all food provided as prepackaged meals.

  • This is possible mostly under laboratory conditions and not yet in free-living conditions. From these observations it should be possible to determine the relevance of the hypothesis to humans and to speculate how these aspects of metabolism may impact the risk of developing related diseases such as coronary heart disease, Type 2 diabetes and certain forms of cancer.

The gene expression of the main lipogenic enzymes is downregulated in visceral adipose tissue of obese subjects. We are grateful to Ulrike Beisiegel for initiating and contributing to the design of the Ulm study cohort. Adipose tissue palmitoleic acid and obesity in humans: does it behave as a lipokine? Abdominal obesity and metabolic syndrome. Markers of de novo lipogenesis in adipose tissue: associations with small adipocytes and insulin sensitivity in humans. Thus, regulation of adipose tissue SCD seems to differ between humans and mice.

A HECP, in conjunction with stable isotopically labeled glucose tracer infusion, was conducted on day 3 to assess hepatic and whole-body insulin sensitivity. Liver fat concentration was lipogenseis on day 8 of each dietary period by magnetic resonance spectrometry on a 3-Tesla scanner. Given the aforementioned evidence that DNL can be acutely increased with hypercaloric feeding and decreased during hypocaloric feeding, weight was monitored daily and diets adjusted to carefully maintain a neutral energy balance. Issue Section:. You can also search for this author in PubMed Google Scholar.

Whole body net de novo lipogenesis after glucose loading was markedly increased at the expense of glycogen synthesis. Discussion: Carbohydrate overfeeding markedly lipkgenesis net de novo lipogenesis at the expense carbohydrate metabolism and de novo lipogenesis in human obesity glycogen synthesis. Many studies have been carried out using a variety of differing experimental protocols on healthy, obese or diabetic humans and animals in positive or neutral energy balance to establish lipogeensis underlying molecular basis for obesity particularly in humans. Although the numerous factors mostly exogenous influencing DNL have been studied, in particular the effect of CHO overfeeding, there is little information on the rate of DNL in habitual conditions of life, that is, large day-to-day fluctuations of CHO intakes, different types of CHO ingested with different glycemic indexes, alcohol combined with excess CHO intakes, etc. Results: Carbohydrate overfeeding increased basal and postglucose energy expenditure and net carbohydrate oxidation. Substances Dietary Carbohydrates Fats Lipids. From these observations it should be possible to determine the relevance of the hypothesis to humans and to speculate how these aspects of metabolism may impact the risk of developing related diseases such as coronary heart disease, Type 2 diabetes and certain forms of cancer.

In addition, these studies established that both isoenergetic and hypercaloric diets high in carbohydrates, especially fructose, are highly lipogenic and produce elevations in DNL that persist after an overnight fast. Close banner Close. Sponsorship of national health organizations by two major soda companies.

Discussion: Carbohydrate overfeeding markedly increased net de novo lipogenesis at the expense of glycogen synthesis. Abstract Many factors affect the onset of obesity including satiety control, reduced levels of physical exercise as well as hormonal and genetic parameters which influence the metabolic pathways leading to the net accumulation of triacylglycerol TAG. Recent studies have demonstrated that acute CHO overfeeding influences adipose tissue lipogenic gene expression and that CHO may stimulate DNL in skeletal muscles, at least in vitro. Adipose tissue biopsies were obtained at the end of the experiments to monitor mRNAs of key lipogenic enzymes. Abstract The measurement of fat balance fat input minus fat output involves the accurate estimation of both metabolizable fat intake and total fat oxidation.

  • Cao, H.

  • This is possible mostly under laboratory conditions and not yet in free-living conditions.

  • Proposed molecular mechanisms of DNL-induced lipotoxicity are, for example, exaggerated synthesis of insulin resistance-inducing ceramides from palmitate C ref.

  • Three issues, which are still controversial today, will be addressed: 1 Is the increase of fat mass induced by CHO overfeeding explained by DNL only, or by decreased endogenous fat oxidation, or both?

From these observations it should be possible to determine the relevance of carbohydrate metabolism and de novo lipogenesis in human obesity hypothesis to humans and to speculate how these aspects of metabolism metaboism impact the risk of developing related diseases such as coronary heart disease, Type 2 diabetes and certain forms of cancer. Results: Carbohydrate overfeeding increased basal and postglucose energy expenditure and net carbohydrate oxidation. Although the numerous factors mostly exogenous influencing DNL have been studied, in particular the effect of CHO overfeeding, there is little information on the rate of DNL in habitual conditions of life, that is, large day-to-day fluctuations of CHO intakes, different types of CHO ingested with different glycemic indexes, alcohol combined with excess CHO intakes, etc. Research methods and procedures: Nine healthy lean volunteers five men and four women were studied after 4 days of either isocaloric feeding or carbohydrate overfeeding.

You have full access to this article via your institution. Huo, Y. Abstract Epidemiologic studies suggest a link between excess sugar consumption and obesity, fatty liver disease, metabolic syndrome, and type 2 diabetes mellitus. Body weight was stable throughout the periods of D 2 O consumption before and after weight loss 0. Therefore, it is possible that differences in study populations between our study and others contributed to differences in hepatic DNL. Search Menu. Activity of DNL enzymes influences tissue fatty acid profiles 4 ,

Next, we asked whether the expression of lipogenic transcription factors was altered in livers of obese subjects in a fashion similar to their putative target genes. Thus, regulation of adipose tissue SCD seems to differ between humans and mice. Abdominal obesity and metabolic syndrome.

Isocaloric fructose restriction and metabolic improvement in children with obesity and metabolic syndrome. Email address Sign up. There is evidence that both hyperinsulinemia and a diet rich in simple sugars, by promoting DNL, contribute to hypertriglyceridemia and liver fat accumulation and, ultimately, to metabolic syndrome. Hepatic DNL was assessed using the deuterated water method corrected for the potential confounding contribution of adipose tissue DNL.

Fructose metabolism is unique because, in contrast to glucose, it is metabolized almost exclusively in the liver, as its anx metabolism is hepatic. This suggests increased SCD activity in adipose tissue of obese individuals and can explain the most prominent fatty acid changes we observed in obese subjects, namely a decrease in C and an increase in Cn9 Fig. HbA1c was measured by turbidimetric inhibition immunoassay Roche Diagnostics. Close banner Close. Find articles by Talukdar, S. Richelsen B.

As far back as BCE, ancient Egyptians deliberately force-fed carbohydrates to birds to fatten them and to produce fatty liver, or foie gras. In addition, our data demonstrate a strong negative correlation between the rate of DNL and both whole-body and hepatic insulin sensitivity and positive correlations with integrated hour plasma glucose and insulin concentrations. This article is also available for rental through DeepDyve. HbA1c was measured by turbidimetric inhibition immunoassay Roche Diagnostics.

  • Fatty acid composition in total lipid extracts of VAT was determined by gas chromatography, as described previously One subject withdrew from the study because of an inability to lose weight; data from 6 subjects are reported here.

  • In case of positive balance, lipids stored in adipose tissue can originate from dietary exogenous lipids or from nonlipid precursors, mainly from carbohydrates CHOs but also from ethanol, through a process known as de novo lipogenesis DNL.

  • Studies conducted in primary hepatocytes and in rodent models of obesity and diabetes support the notion of selective pathway—specific insulin resistance in the liver 31 —

  • An increase in mRNAs coding for key lipogenic enzymes suggests that de novo lipogenesis occurred, at least in part, in adipose tissue. Substances Dietary Carbohydrates Fats Lipids.

  • The hypothesis focuses on the central role of stearoyl-CoA desaturase SCD and its inhibition by polyunsaturated fatty acids PUFAs acting via transcription factors based upon data obtained from both animal and human studies.

Basic equations are provided in this review to facilitate the interpretation of the different subcomponents of fat balance endogenous vs exogenous under different nutritional circumstances. Abstract The measurement of fat balance fat input minus fat output involves the accurate estimation of both metabolizable fat intake and obesity fat oxidation. Publication types Review. From these observations it should be possible to determine the relevance of the hypothesis to humans and to speculate how these aspects of metabolism may impact the risk of developing related diseases such as coronary heart disease, Type 2 diabetes and certain forms of cancer. On each occasion, they underwent a metabolic study during which their energy expenditure and net substrate oxidation rates indirect calorimetryand the fractional activity of the pentose-phosphate pathway in subcutaneous adipose tissue subcutaneous microdialysis with 1,6 13 C2,6,6 2 H2 glucose were assessed before and after administration of glucose.

Consequently, both carbohydrates and lipids are potential sources of these stored lilogenesis. Recent studies have demonstrated that acute CHO overfeeding influences adipose tissue lipogenic gene expression and that CHO may stimulate DNL in skeletal muscles, at least in vitro. Results: Carbohydrate overfeeding increased basal and postglucose energy expenditure and net carbohydrate oxidation. Abstract The measurement of fat balance fat input minus fat output involves the accurate estimation of both metabolizable fat intake and total fat oxidation.

Although the numerous factors mostly exogenous influencing DNL have been studied, in particular the effect of CHO overfeeding, there is little information on the rate of DNL in habitual conditions of life, that is, carbohydrate metabolism and de novo lipogenesis in human obesity day-to-day fluctuations of CHO intakes, different types of CHO ingested with different glycemic indexes, alcohol combined with excess CHO intakes, etc. Adipose tissue biopsies were obtained at the end of the experiments to monitor mRNAs of key lipogenic enzymes. On each occasion, they underwent a metabolic study during which their energy expenditure and net substrate oxidation rates indirect calorimetryand the fractional activity of the pentose-phosphate pathway in subcutaneous adipose tissue subcutaneous microdialysis with 1,6 13 C2,6,6 2 H2 glucose were assessed before and after administration of glucose.

The hypothesis focuses on the central role of stearoyl-CoA desaturase SCD and its inhibition by polyunsaturated fatty acids Ccarbohydrate acting via transcription factors based upon data obtained from both animal and human studies. Substances Dietary Carbohydrates Fats Lipids. The role of DNL and its importance in health and disease remain to be further metavolism, in particular the putative effect of DNL on the control of energy intake and energy expenditure, as well as the occurrence of DNL in other tissues such as in myocytes in addition to hepatocytes and adipocytes. On each occasion, they underwent a metabolic study during which their energy expenditure and net substrate oxidation rates indirect calorimetryand the fractional activity of the pentose-phosphate pathway in subcutaneous adipose tissue subcutaneous microdialysis with 1,6 13 C2,6,6 2 H2 glucose were assessed before and after administration of glucose. Objective: To evaluate the effect of a 4-day carbohydrate overfeeding on whole body net de novo lipogenesis and on markers of de novo lipogenesis in subcutaneous adipose tissue of healthy lean humans. Carbohydrate overfeeding also increased mRNA levels for the key lipogenic enzymes sterol regulatory element-binding protein-1c, acetyl-CoA carboxylase, and fatty acid synthase.

  • Close mobile search navigation Article Navigation. Next, we asked whether the expression of lipogenic transcription factors was altered in livers of obese subjects in a fashion similar to their putative target genes.

  • Basic equations are provided in this review to facilitate the interpretation of the different subcomponents of fat balance endogenous vs exogenous under different nutritional circumstances.

  • Taken together, these data underscore the importance of DNL in the pathogenesis of hepatic steatosis and suggest that increases in daily hour plasma glucose and insulin concentrations are major drivers of increased DNL in individuals with obesity and NAFLD. Yang, Z.

  • The pentose-phosphate pathway is active in adipose tissue of healthy humans, consistent with an active role of this tissue in de novo lipogenesis. An increase in mRNAs coding for key lipogenic enzymes suggests that de novo lipogenesis occurred, at least in part, in adipose tissue.

  • Abstract Many factors affect the onset of obesity including satiety control, reduced levels of physical exercise as well as hormonal and genetic parameters which influence the metabolic pathways leading to the net accumulation of triacylglycerol TAG. From these observations it should be possible to determine the relevance of the hypothesis to humans and to speculate how these aspects of metabolism may impact the risk of developing related diseases such as coronary heart disease, Type 2 diabetes and certain forms of cancer.

Quantification of menstrual and diurnal periodicities in rates of cholesterol and fat synthesis in humans. View author publications. Yamashita, H. The problem of establishing relationships between hepatic steatosis and hepatic insulin resistance.

Research methods and procedures: Nine healthy lean volunteers five men and four women were studied after 4 days of either isocaloric feeding or carbohydrate overfeeding. Publication types Review. Objective: To huuman the human obesity of a 4-day carbohydrate overfeeding on whole body net de novo lipogenesis and on markers of de novo lipogenesis in subcutaneous adipose tissue of healthy lean humans. The measurement of fat balance fat input minus fat output involves the accurate estimation of both metabolizable fat intake and total fat oxidation. The hypothesis focuses on the central role of stearoyl-CoA desaturase SCD and its inhibition by polyunsaturated fatty acids PUFAs acting via transcription factors based upon data obtained from both animal and human studies.

In case of positive balance, lipids stored in adipose tissue can originate from dietary exogenous lipids or from nonlipid precursors, mainly from carbohydrates CHOs but also from ethanol, through a process known as de novo lipogenesis DNL. Many factors affect the onset of obesity including satiety control, reduced levels of physical exercise as well as hormonal and genetic parameters which influence the metabolic pathways leading to the net accumulation of triacylglycerol TAG. Carbohydrate overfeeding also increased mRNA levels for the key lipogenic enzymes sterol regulatory element-binding protein-1c, acetyl-CoA carboxylase, and fatty acid synthase.

The supernatant was then collected while carefully avoiding the lipid layer on top and protein concentration was measured with a BCA protein quantification kit Thermo Scientific. Toll-like receptor signaling links dietary fatty acids to the metabolic syndrome. Obes Res. Diminished activities of fatty acid synthesis enzymes in insulin-resistant adipocytes from spontaneously obese rats. After 8 days consuming the high-fructose diet, mean SD DNL during feeding was significantly higher with the low-fructose group

  • Garvey, W.

  • Many studies have been carried out using a variety of differing experimental protocols on healthy, obese or diabetic humans and animals in positive or neutral energy balance to establish the underlying molecular basis for obesity particularly in humans.

  • Find articles by Talukdar, S.

  • Carbohydrate overfeeding also increased mRNA levels for the key lipogenic enzymes sterol regulatory element-binding protein-1c, acetyl-CoA carboxylase, and fatty acid synthase. Publication types Research Support, Non-U.

  • Although the numerous factors mostly exogenous influencing DNL have been studied, in carbohydratw the effect of CHO overfeeding, there is little information on the rate of DNL in habitual conditions of life, that is, large day-to-day fluctuations of CHO intakes, different types of CHO ingested with different glycemic indexes, alcohol combined with excess CHO intakes, etc. The predominant fatty acid of human adipose tissue TAGs is oleic acid, reflecting primarily the composition of the diet but also the product of de novo lipogenesis.

Carbohydrate overfeeding also increased mRNA levels for the key lipogenic enzymes sterol regulatory element-binding protein-1c, acetyl-CoA carboxylase, carbohydrate metabolism and de novo lipogenesis in human obesity fatty acid synthase. Although the numerous factors mostly exogenous influencing DNL have been studied, in particular the effect of CHO overfeeding, there is little information on the rate of DNL in habitual conditions of life, that is, large day-to-day fluctuations of CHO intakes, different types of CHO ingested with different glycemic indexes, alcohol combined with excess CHO intakes, etc. The predominant fatty acid of human adipose tissue TAGs is oleic acid, reflecting primarily the composition of the diet but also the product of de novo lipogenesis. Abstract Many factors affect the onset of obesity including satiety control, reduced levels of physical exercise as well as hormonal and genetic parameters which influence the metabolic pathways leading to the net accumulation of triacylglycerol TAG. Substances Dietary Carbohydrates Fats Lipids. Discussion: Carbohydrate overfeeding markedly increased net de novo lipogenesis at the expense of glycogen synthesis. This is possible mostly under laboratory conditions and not yet in free-living conditions.

The pentose-phosphate pathway is active in adipose tissue of healthy humans, consistent with an active role of this tissue in i novo lipogenesis. Basic equations are provided in this review to facilitate the interpretation of the different subcomponents of fat balance endogenous vs exogenous under different nutritional circumstances. An increase in mRNAs coding for key lipogenic enzymes suggests that de novo lipogenesis occurred, at least in part, in adipose tissue. Consequently, both carbohydrates and lipids are potential sources of these stored fats.

Plasma LDL cholesterol concentration was calculated according to the Friedewald formula Fatty acid composition in total lipid extracts of VAT was determined by gas chromatography, as described previously Second, we avoided overestimating the potential contribution of fatty acids synthesized de novo in adipose tissue that could have been released into the circulation and incorporated into VLDL-TGs in the liver 14 — About this article Cite this article Eissing, L.

In case of positive balance, lipids stored in adipose tissue can originate from dietary exogenous lipids or obeskty nonlipid precursors, mainly from carbohydrates CHOs but also from ethanol, through a process known as de novo lipogenesis DNL. Publication types Research Support, Non-U. The hypothesis focuses on the central role of stearoyl-CoA desaturase SCD and its inhibition by polyunsaturated fatty acids PUFAs acting via transcription factors based upon data obtained from both animal and human studies. Three issues, which are still controversial today, will be addressed: 1 Is the increase of fat mass induced by CHO overfeeding explained by DNL only, or by decreased endogenous fat oxidation, or both?

Effects of enteral carbohydrates on de novo lipogenesis in critically ill patients. Despite massive liver triglyceride accumulation, these mice were not insulin resistant, and on high-fat diet even more insulin sensitive than controls Open bars and symbols are females; RPearson correlation coefficient. To what extent Cn7 is an insulin-sensitizing factor in humans, as it is in mice 467is a matter of ongoing debate 434445 and cannot be directly inferred from our data. Wu, M.

Recent studies have demonstrated that acute CHO overfeeding influences adipose tissue lipogenic gene expression and that CHO may stimulate DNL in skeletal muscles, at least in vitro. In case of positive balance, lipids stored in adipose tissue can originate from dietary exogenous lipids or from nonlipid precursors, mainly from carbohydrates CHOs but also from ethanol, through a process known as de novo lipogenesis DNL. Abstract Many factors affect the onset of obesity including satiety control, reduced levels of physical exercise as well as hormonal and genetic parameters which influence the metabolic pathways leading to the net accumulation of triacylglycerol TAG.

Publication types Review. Many factors affect the onset of obesity including satiety control, reduced levels of physical exercise as well as hormonal and genetic parameters which influence the metabolic pathways leading to the net accumulation of triacylglycerol TAG. Publication types Research Support, Non-U. Many studies have been carried out using a variety of differing experimental protocols on healthy, obese or diabetic humans and animals in positive or neutral energy balance to establish the underlying molecular basis for obesity particularly in humans. Adipose tissue biopsies were obtained at the end of the experiments to monitor mRNAs of key lipogenic enzymes.

Research methods and procedures: Nine healthy lean volunteers five men and four women were studied after 4 days of either novo feeding or carbohydrate overfeeding. Abstract Objective: To evaluate the effect of a 4-day carbohydrate overfeeding on whole body net de novo lipogenesis and on markers of de novo lipogenesis in subcutaneous adipose tissue of healthy lean humans. The predominant fatty acid of human adipose tissue TAGs is oleic acid, reflecting primarily the composition of the diet but also the product of de novo lipogenesis. The pentose-phosphate pathway is active in adipose tissue of healthy humans, consistent with an active role of this tissue in de novo lipogenesis.

Results: Carbohydrate overfeeding increased basal and postglucose energy expenditure and net carbohydrate oxidation. Abstract Many factors affect the onset of obesity including satiety control, reduced levels of physical exercise as well as hormonal and genetic parameters which influence the metabolic pathways leading to the net accumulation of triacylglycerol TAG. Abstract Objective: To evaluate the effect of a 4-day carbohydrate overfeeding on whole body net de novo lipogenesis and on markers of de novo lipogenesis in subcutaneous adipose tissue of healthy lean humans. In case of positive balance, lipids stored in adipose tissue can originate from dietary exogenous lipids or from nonlipid precursors, mainly from carbohydrates CHOs but also from ethanol, through a process known as de novo lipogenesis DNL. From these observations it should be possible to determine the relevance of the hypothesis to humans and to speculate how these aspects of metabolism may impact the risk of developing related diseases such as coronary heart disease, Type 2 diabetes and certain forms of cancer.

Anyone can find disease. Sample analyses. Furthermore, we show that in obesity, liver DNL is profoundly upregulated, and is closely carbihydrate to insulin resistance as well as liver steatosis. Abdominal SAT resection specimens were obtained from 20 patients 15 females, 5 males during bariatric surgery performed at Maastricht University Hospital, The Netherlands, from — The diets were given during consecutive 9-day periods. Clear recommendation about moderating sugar intake to patients may be an important nonpharmacologic tool to include in clinical practice. In contrast to VAT Fig.

  • Thus, excessive hepatic DNL does not invariably cause insulin resistance. Effect of fructose overfeeding and fish oil administration on hepatic de novo lipogenesis and insulin sensitivity in healthy men.

  • Publication types Review. Basic equations are provided in this review to facilitate the interpretation of the different subcomponents of fat balance endogenous vs exogenous under different nutritional circumstances.

  • Sugar-sweetened beverages and risk of hypertension and CVD: a dose-response meta-analysis.

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Discussion: Carbohydrate overfeeding markedly increased net de novo lipogenesis at the expense of glycogen synthesis. Carbohydrate overfeeding also increased mRNA levels for the key lipogenic enzymes sterol regulatory element-binding protein-1c, acetyl-CoA carboxylase, and fatty acid synthase. Results: Carbohydrate overfeeding increased basal and postglucose energy expenditure and net carbohydrate oxidation. Three issues, which are still controversial today, will be addressed: 1 Is the increase of fat mass induced by CHO overfeeding explained by DNL only, or by decreased endogenous fat oxidation, or both?

Owing to sample limitations we were only ad to analyse a small set of liver tissue specimens, different from the subgroups described in Table 1 see Supplementary Table S3. Conflicts of interest in the regulation of food safety: a threat to scientific integrity. Protein extraction and western blot analysis were performed as described Accessed June 5, Download all slides.

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