Dietary treatment of overweight and obesity
G. Michael Steelman, Eric C. Westman in Obesity, 2016
The rationale of the dietary treatment of the obese individual is to alter the hormonal milieu to direct the body’s metabolism away from fat storage (lipogenesis) and toward fat mobilization and oxidation. Using carbohydrate as the body’s main fuel is metabolically linked to lipogenesis (Figure 5.1). Nutritional ketosis is useful for treating obesity and many similar conditions (Table 5.2). Body systems can be directed toward fat oxidation in many ways, for example, through carbohydrate restriction or caloric restriction since caloric restriction is usually achieved at least, in part, by carbohydrate restriction. Nutritional ketosis is a metabolic state in which fat and ketones are the major fuel sources to generate ATP while glycolysis is minimized (Figure 5.2). Although often misconstrued as harmful or unhealthy, nutritional ketosis is not known to cause any short-or long-term adverse consequences. In fact, many indigenous populations living on very-low–carbohydrate diets were likely in chronic nutritional ketosis. Nutritional ketosis causes a relatively low level of serum ketone elevation and is not associated with a reduction in pH or significant metabolic acidosis (15). Frequently, nutritional ketosis is confused with diabetic ketoacidosis—the metabolic state during which the absence of insulin leads to very high levels of ketones along with elevated blood glucose, dehydration, and a low blood pH.
Nonalcoholic Fatty Liver Disease
Nicole M. Farmer, Andres Victor Ardisson Korat in Cooking for Health and Disease Prevention, 2022
Flavonoids and polyphenols are classes of phytonutrients commonly stored in the pigmentation of various fruits, vegetables, and other plant material (Heneman and Zidenberg-Cherr 2008). These two classes of phytochemicals have been noted to be useful for the treatment and prevention of disease states such as cancer, cardiovascular disease, and other metabolic conditions such as NAFLD (Fry 2017c). Flavonoids, substances derived from citrus, have been observed to prevent hepatic steatosis, dyslipidemia, and insulin sensitivity by decreasing fat production in the liver while also decreasing inflammation of the liver (Assini, Mulvihill, and Huff 2013). Regulation of oxidative stress, inflammation, lipid metabolism, immune response, insulin resistance, and gut microbiota are fundamental characteristics of the effects of polyphenols on the body and contribute to the prevention and treatment of liver conditions (Li et al. 2018). Specifically, polyphenols inhibit lipogenesis, the metabolic formation of fat, reducing fat accumulation in the liver (Ben, Polimeni, Barrata, Pastori, and Angelico 2017).
Mitigation of Obesity: A Phytotherapeutic Approach
Amit Baran Sharangi, K. V. Peter in Medicinal Plants, 2023
Altered lipid metabolic processes together with lipogenesis and lipolysis facilitate the development of obesity (Pagliassotti et al., 1997). Synthetic moieties and surgical procedures are the universal therapy of obesity, but have detrimental side effects and likelihood of severe recurrence (Karri et al., 2019). Lipogenesis stores free fatty acids in the form of triglyceride (Mandrup and Lane, 1997); whereas in lipolysis, the stored triglyceride is metabolized to free fatty acids and glycerol (Ducharme and Bichel, 2008). Obesity is accompanied by an abnormally high concentration of lipids in blood, i.e., hyperlipidemia (Akiyama et al., 1996). The adipose tissue secretes several biologically active adipokines and thereby regulates metabolism and homeostasis (Yudkin et al., 1999). Three key transcription factors like peroxisome proliferator-activated receptor (PPAR), CCAAT/enhancer-binding protein (C/EBP) and sterol regulatory element-binding protein (SREBP) regulate the expression of these lipid-metabolizing enzymes during adipose tissue development (Freytag and Utter, 1983). 5’ AMP-activated protein kinase (AMPK) plays a major role in lipid and glucose metabolism by inactivating acetyl-CoA carboxylase (ACC) and Through up-regulating the expression of carnitine palmitoyl transferase-1 (CPT-1), PPAR, and uncoupling protein, stimulation of fatty acid oxidation is done (Kim et al., 2007).
Bacteroides uniformis combined with fiber amplifies metabolic and immune benefits in obese mice
Published in Gut Microbes, 2021
Inmaculada López-Almela, Marina Romaní-Pérez, Clara Bullich-Vilarrubias, Alfonso Benítez-Páez, Eva M. Gómez Del Pulgar, Rubén Francés, Gerhard Liebisch, Yolanda Sanz
The effects of the B. uniformis–WBE combination on adiposity were parallel to improvements of some insulin-regulated metabolic routes in adipose tissue and liver. Notably, HFHSD reduced lipogenesis in epididymal fat and hepatic glycogenesis, while both routes were normalized by the B. uniformis–WBE combination. In visceral fat, this intervention restored lipogenic markers (Acc and Fas) and the transcriptional factor regulating their expression Chrebpα.19 The expression of lipogenic enzymes and Chrebp in WAT positively correlates to insulin sensitivity in obesity. In fact, the reactivation of de novo lipogenesis in the adipose tissue, which mainly uses glycolysis-derived metabolites as precursors of fatty acids, acts as an insulin sensitizer mechanism improving whole-body metabolism in obese subjects.20–22 We also showed hepatic glycogen depots were restored by the B. uniformis–WBE combination, which were reduced by HFHSD, supporting a cross-talk between the visceral fat and liver. Furthermore, the combined intervention enhanced both, Gck expression, which is insulin-dependent23 and its enzymatic product G6P, diminished in mice fed HFHSD. However, this effect was primarily driven by B. uniformis as it was also identified in group receiving bacteria alone supporting a major contribution of the bacterium restoring hepatic glycogenesis.
Effects of short-term fasting and pharmacological activation of AMPK on metabolism of rat adipocytes
Published in Archives of Physiology and Biochemistry, 2021
Tomasz Szkudelski, Katarzyna Szkudelska
The cells of white adipose tissue, adipocytes, store large amounts of energy in the form of lipids. Adipocytes release glycerol and fatty acids or, depending on the actual demand of the organism, synthesise triglycerides from glycerol, fatty acids, and glucose. This is an important feature and thereby adipose tissue is an important element of whole-body energy homeostasis (Luo and Liu 2016). It is well established that dysregulation of the balance between lipogenesis and lipolysis is associated with insufficient or exaggerated accumulation of fat tissue in the body (Frühbeck et al. 2014). The latter effect leads to overweight or obesity and a risk of insulin resistance. Moreover, the link between excessive adipose tissue accumulation and inflammation is recently well established (Jung and Choi 2014). Adipose tissue secretes also adipokines, which have a relevant regulatory role. Thereby, adipose tissue is involved in the regulation, among others, of feeding behaviour and energy expenditure (Luo and Liu 2016). The rate of lipogenesis and lipolysis in the adipocytes, and also secretion of adipokines changes depending on various conditions. Under physiological conditions, these processes are strongly affected by hormones, circadian activity and the resulting changes in food ingestion, physical activity, and fasting. Energy deprivation is known to affect adipocyte lipid storage and also secretion of adipokines. Fasting is associated with reduced lipogenesis and increased lipolysis, and also with changes in secretion of some adipokines (Luo and Liu 2016).
Characterization of free fatty acid receptors expression in an obesity rat model with high sucrose diet
Published in Journal of Receptors and Signal Transduction, 2018
Fabián Meza-Cuenca, J. M. L. Medina-Contreras, Patrick Mailloux-Salinas, Luis A. Bautista-Hernández, Beatríz Buentello-Volante, Alfredo Domínguez-López, Yonathan Garfias, P. Valentín Correa-López, Víctor M. Bautista de Lucio, Guadalupe Bravo
For this reason, another important aspect of this 30% sucrose for 20 weeks was the level of plasmatic glucose in the obese group, that did not show differences when compared with the regular pellets chow diet (no obese group), but not more than compared with a diabetes high-fed diet models. On this point, Kergoat et al. [12] mentioned that the sucrose content of the diet has a major effect on glucose tolerance and insulin secretion in humans as well as laboratory animals. They reported that sucrose feeding markedly increases basal insulin levels as well as glucose-stimulated insulin release. Additionally, Lima et al. [13] demonstrated that a simple carbohydrate-rich diet was associated with an increased serum level of glucose, triglycerides, VLDL-cholesterol and insulin, which could be due to the de novo hepatic lipogenesis, which is aggravated by this kind of diets (higher carbohydrate content), similar to our results in the levels of triglycerides, total-cholesterol and glucose levels results in the obese group.
Related Knowledge Centers
- Biochemistry
- Chemical Synthesis
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- Glycerol
- Metabolism
- Adipose Tissue
- Acetyl-Coa
- Triglyceride