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Nutrients Dec 2022Research shows that reduced sleep duration is related to an increased risk of obesity. The relationship between sleep deprivation and obesity, type 2 diabetes, and other... (Review)
Review
Research shows that reduced sleep duration is related to an increased risk of obesity. The relationship between sleep deprivation and obesity, type 2 diabetes, and other chronic diseases may be related to the imbalance of appetite regulation. To comprehensively illustrate the specific relationship between sleep deprivation and appetite regulation, this review introduces the pathophysiology of sleep deprivation, the research cutting edge of animal models, and the central regulatory mechanism of appetite under sleep deprivation. This paper summarizes the changes in appetite-related hormones orexin, ghrelin, leptin, and insulin secretion caused by long-term sleep deprivation based on the epidemiology data and animal studies that have established sleep deprivation models. Moreover, this review analyzes the potential mechanism of associations between appetite regulation and sleep deprivation, providing more clues on further studies and new strategies to access obesity and metabolic disease.
Topics: Animals; Sleep Deprivation; Appetite Regulation; Diabetes Mellitus, Type 2; Leptin; Ghrelin; Obesity; Appetite; Sleep
PubMed: 36558355
DOI: 10.3390/nu14245196 -
International Journal of Environmental... Sep 2021Development of obesity is primarily the result of imbalance between energy intake and energy expenditure. Thyroid hormones influence energy expenditure by regulating... (Review)
Review
Development of obesity is primarily the result of imbalance between energy intake and energy expenditure. Thyroid hormones influence energy expenditure by regulating cellular respiration and thermogenesis and by determining resting metabolic rate. Triiodothyronine influences lipid turnover in adipocytes and impacts appetite regulation through the central nervous system, mainly the hypothalamus. Thyroid-stimulating hormone may also influence thermogenesis, suppress appetite and regulate lipid storage through lipolysis and lipogenesis control. Subclinical hypothyroidism may induce changes in basal metabolic rate with subsequent increase in BMI, but obesity can also affect thyroid function via several mechanisms such as lipotoxicity and changes in adipokines and inflammatory cytokine secretion. The present study investigated the complex and mutual relationships between the thyroid axis and adiposity.
Topics: Basal Metabolism; Energy Metabolism; Humans; Obesity; Thermogenesis; Thyroid Gland
PubMed: 34574358
DOI: 10.3390/ijerph18189434 -
Obesity (Silver Spring, Md.) Apr 2022New appetite-regulating antiobesity treatments such as semaglutide and agents under investigation such as tirzepatide show promise in achieving weight loss of 15% or... (Review)
Review
New appetite-regulating antiobesity treatments such as semaglutide and agents under investigation such as tirzepatide show promise in achieving weight loss of 15% or more. Energy expenditure, fat oxidation, and lean mass preservation are important determinants of weight loss and weight-loss maintenance beyond appetite regulation. This review discusses prior failures in clinical development of weight-loss drugs targeting energy expenditure and explores novel strategies for targeting energy expenditure: mitochondrial proton leak, uncoupling, dynamics, and biogenesis; futile calcium and substrate cycling; leptin for weight maintenance; increased sympathetic nervous system activity; and browning of white fat. Relevant targets for preserving lean mass are also reviewed: growth hormone, activin type II receptor inhibition, and urocortin 2 and 3. We endorse moderate modulation of energy expenditure and preservation of lean mass in combination with efficient appetite reduction as a means of obtaining a significant, safe, and long-lasting weight loss. Furthermore, we suggest that the regulatory guidelines should be revisited to focus more on the quality of weight loss and its maintenance rather than the absolute weight loss. Commitment to this research focus both from a scientific and from a regulatory point of view could signal the beginning of the next era in obesity therapies.
Topics: Appetite; Appetite Regulation; Energy Metabolism; Humans; Obesity; Weight Loss
PubMed: 35333444
DOI: 10.1002/oby.23374 -
Clinics and Research in Hepatology and... Feb 2022Food intake and energy expenditure are key regulators of body weight. To regulate food intake, the brain must integrate physiological signals and hedonic cues. The brain... (Review)
Review
Food intake and energy expenditure are key regulators of body weight. To regulate food intake, the brain must integrate physiological signals and hedonic cues. The brain plays an essential role in modulating the appropriate responses to the continuous update of the body energy-status by the peripheral signals and the neuronal pathways that generate the gut-brain axis. This regulation encompasses various steps involved in food consumption, include satiation, satiety, and hunger. It is important to have a comprehensive understanding of the mechanisms that regulate food consumption as well as to standardize the vocabulary for the steps involved. This review discusses the current knowledge of the regulation and the contribution peripheral and central signals at each step of the cycle to control appetite. We also highlight how food intake has been measured. The increasingly complex understanding of regulation and action mechanisms intervening in the gut-brain axis offers ambitious targets for new strategies to control appetite.
Topics: Appetite; Eating; Homeostasis; Humans; Hunger; Satiation
PubMed: 34481092
DOI: 10.1016/j.clinre.2021.101794 -
Reviews in Endocrine & Metabolic... Sep 2020Dietary proteins have been used for years to treat obesity. Body weight loss is beneficial when it concerns fat mass, but loss of fat free mass - especially muscle might... (Review)
Review
Dietary proteins have been used for years to treat obesity. Body weight loss is beneficial when it concerns fat mass, but loss of fat free mass - especially muscle might be detrimental. This occurs because protein breakdown predominates over synthesis, thus administering anabolic dietary compounds like proteins might counter fat free mass loss while allowing for fat mass loss.Indeed, varying the quantity of proteins will decrease muscle anabolic response and increase hyperphagia in rodents fed a low protein diet; but it will favor lean mass maintenance and promote satiety, in certain age groups of humans fed a high protein diet. Beyond protein quantity, protein source is an important metabolic regulator: whey protein and plant based diets exercize favorable effects on the risk of developing obesity, body composition, metabolic parameters or fat free mass preservation of obese patients. Specific amino-acids like branched chain amino acids (BCAA), methionine, tryptophan and its metabolites, and glutamate can also positively influence parameters and complications of obesity especially in rodent models, with less studies translating this in humans.Tuning the quality and quantity of proteins or even specific amino-acids can thus be seen as a potential therapeutic intervention on the body composition, metabolic syndrome parameters and appetite regulation of obese patients. Since these effects vary across age groups and much of the data comes from murine models, long-term prospective studies modulating proteins and amino acids in the human diet are needed.
Topics: Amino Acids; Amino Acids, Branched-Chain; Animals; Diet; Diet, High-Protein; Dietary Proteins; Energy Metabolism; Humans; Mice; Obesity
PubMed: 32827096
DOI: 10.1007/s11154-020-09574-5 -
Journal of Applied Physiology... Mar 2023No longer viewed as a metabolic waste product and cause of muscle fatigue, a contemporary view incorporates the roles of lactate in metabolism, sensing and signaling in... (Review)
Review
No longer viewed as a metabolic waste product and cause of muscle fatigue, a contemporary view incorporates the roles of lactate in metabolism, sensing and signaling in normal as well as pathophysiological conditions. Lactate exists in millimolar concentrations in muscle, blood, and other tissues and can rise more than an order of magnitude as the result of increased production and clearance limitations. Lactate exerts its powerful driver-like influence by mass action, redox change, allosteric binding, and other mechanisms described in this article. Depending on the condition, such as during rest and exercise, following carbohydrate nutrition, injury, or pathology, lactate can serve as a myokine or exerkine with autocrine-, paracrine-, and endocrine-like functions that have important basic and translational implications. For instance, lactate signaling is: involved in reproductive biology, fueling the heart, muscle adaptation, and brain executive function, growth and development, and a treatment for inflammatory conditions. Lactate also works with many other mechanisms and factors in controlling cardiac output and pulmonary ventilation during exercise. Ironically, lactate can be disruptive of normal processes such as insulin secretion when insertion of lactate transporters into pancreatic β-cell membranes is not suppressed, and in carcinogenesis when factors that suppress carcinogenesis are inhibited, whereas factors that promote carcinogenesis are upregulated. Lactate signaling is important in areas of intermediary metabolism, redox biology, mitochondrial biogenesis, neurobiology, gut physiology, appetite regulation, nutrition, and overall health and vigor. The various roles of lactate as a myokine and exerkine are reviewed. Lactate sensing and signaling is a relatively new and rapidly changing field. As a physiological signal lactate works both independently and in concert with other signals. Lactate operates via covalent binding and canonical signaling, redox change, and lactylation of DNA. Lactate can also serve as an element of feedback loops in cardiopulmonary regulation. From conception through aging lactate is not the only a myokine or exerkine, but it certainly deserves consideration as a physiological signal.
Topics: Humans; Lactic Acid; Muscles; Exercise; Oxidation-Reduction; Carcinogenesis
PubMed: 36633863
DOI: 10.1152/japplphysiol.00497.2022 -
Physiological Research Apr 2021This paper reviews provenance, chemical composition and properties of tea (Camelia sinensis L.) and coffee (Coffee arabica, L. and Coffeacaniphora, L.), their general... (Review)
Review
This paper reviews provenance, chemical composition and properties of tea (Camelia sinensis L.) and coffee (Coffee arabica, L. and Coffeacaniphora, L.), their general health effects, as well as the currently available knowledge concerning their action on fat storage, physiological mechanisms of their effects, as well as their safety and recommended dosage for treatment of obesity. Both tea and coffee possess the ability to promote health and to prevent, to mitigate and to treat numerous disorders. This ability can be partially due to presence of caffeine in both plants. Further physiological and medicinal effects could be explained by other molecules (theaflavins, catechins, their metabolites and polyphenols in tea and polyphenol chlorogenic acid in coffee). These plants and plant molecules can be efficient for prevention and treatment of numerous metabolic disorders including metabolic syndrome, cardiovascular diseases, type 2 diabetes and obesity. Both plants and their constituents can reduce fat storage through suppression of adipocyte functions, and support of gut microbiota. In addition, tea can prevent obesity via reduction of appetite, food consumption and food absorption in gastrointestinal system and through the changes in fat metabolism.
Topics: Adiposity; Animals; Anti-Obesity Agents; Appetite Regulation; Coffee; Health Status; Humans; Lipid Metabolism; Obesity; Phytochemicals; Tea; Weight Gain
PubMed: 33992045
DOI: 10.33549/physiolres.934674 -
Cell Jan 2020The function of central appetite neurons is instructing animals to ingest specific nutrient factors that the body needs. Emerging evidence suggests that individual... (Review)
Review
The function of central appetite neurons is instructing animals to ingest specific nutrient factors that the body needs. Emerging evidence suggests that individual appetite circuits for major nutrients-water, sodium, and food-operate on unique driving and quenching mechanisms. This review focuses on two aspects of appetite regulation. First, we describe the temporal relationship between appetite neuron activity and consumption behaviors. Second, we summarize ingestion-related satiation signals that differentially quench individual appetite circuits. We further discuss how distinct appetite and satiation systems for each factor may contribute to nutrient homeostasis from the functional and evolutional perspectives.
Topics: Animals; Appetite; Appetite Regulation; Brain; Feeding Behavior; Homeostasis; Humans; Hunger; Nervous System Physiological Phenomena; Neurons; Satiation; Sodium; Thirst
PubMed: 31923398
DOI: 10.1016/j.cell.2019.11.040 -
Cells Nov 2021Growth differentiation factor 15 (GDF15) is a cytokine best known for affecting systemic energy metabolism through its anorectic action. GDF15 expression and secretion... (Review)
Review
Growth differentiation factor 15 (GDF15) is a cytokine best known for affecting systemic energy metabolism through its anorectic action. GDF15 expression and secretion from various organs and tissues is induced in different physiological and pathophysiological states, often linked to mitochondrial stress, leading to highly variable circulating GDF15 levels. In skeletal muscle and the heart, the basal expression of GDF15 is very low compared to other organs, but GDF15 expression and secretion can be induced in various stress conditions, such as intense exercise and acute myocardial infarction, respectively. GDF15 is thus considered as a myokine and cardiokine. GFRAL, the exclusive receptor for GDF15, is expressed in hindbrain neurons and activation of the GDF15-GFRAL pathway is linked to an increased sympathetic outflow and possibly an activation of the hypothalamic-pituitary-adrenal (HPA) stress axis. There is also evidence for peripheral, direct effects of GDF15 on adipose tissue lipolysis and possible autocrine cardiac effects. Metabolic and behavioral outcomes of GDF15 signaling can be beneficial or detrimental, likely depending on the magnitude and duration of the GDF15 signal. This is especially apparent for GDF15 production in muscle, which can be induced both by exercise and by muscle disease states such as sarcopenia and mitochondrial myopathy.
Topics: Animals; Circadian Rhythm; Exercise; Growth Differentiation Factor 15; Hormesis; Humans; Muscle, Skeletal; Signal Transduction
PubMed: 34831213
DOI: 10.3390/cells10112990 -
The Journal of Physiology Mar 2022Daily (circadian) rhythms coordinate our physiology and behaviour with regular environmental changes. Molecular clocks in peripheral tissues (e.g. liver, skeletal muscle... (Review)
Review
Daily (circadian) rhythms coordinate our physiology and behaviour with regular environmental changes. Molecular clocks in peripheral tissues (e.g. liver, skeletal muscle and adipose) give rise to rhythms in macronutrient metabolism, appetite regulation and the components of energy balance such that our bodies can align the periodic delivery of nutrients with ongoing metabolic requirements. The timing of meals both in absolute terms (i.e. relative to clock time) and in relative terms (i.e. relative to other daily events) is therefore relevant to metabolism and health. Experimental manipulation of feeding-fasting cycles can advance understanding of the effect of absolute and relative timing of meals on metabolism and health. Such studies have extended the overnight fast by regular breakfast omission and revealed that morning fasting can alter the metabolic response to subsequent meals later in the day, whilst also eliciting compensatory behavioural responses (i.e. reduced physical activity). Similarly, restricting energy intake via alternate-day fasting also has the potential to elicit a compensatory reduction in physical activity, and so can undermine weight-loss efforts (i.e. to preserve body fat stores). Interrupting the usual overnight fast (and therefore also the usual sleep cycle) by nocturnal feeding has also been examined and further research is needed to understand the importance of this period for either nutritional intervention or nutritional withdrawal. In summary, it is important for dietary guidelines for human health to consider nutrient timing (i.e. when we eat) alongside the conventional focus on nutrient quantity and nutrient quality (i.e. how much we eat and what we eat).
Topics: Breakfast; Circadian Rhythm; Energy Intake; Energy Metabolism; Feeding Behavior; Humans; Meals; Nutrients
PubMed: 35038774
DOI: 10.1113/JP280756