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Neuroscience and Biobehavioral Reviews Sep 2017The brain-gut-axis is an interdependent system affecting neural functions and controlling our eating behaviour. In recent decades, neuroimaging techniques have... (Review)
Review
The brain-gut-axis is an interdependent system affecting neural functions and controlling our eating behaviour. In recent decades, neuroimaging techniques have facilitated its investigation. We systematically looked into functional and neurochemical brain imaging studies investigating how key molecules such as ghrelin, glucagon-like peptide-1 (GLP-1), peptide tyrosine-tyrosine (PYY), cholecystokinin (CCK), leptin, glucose and insulin influence the function of brain regions regulating appetite and satiety. Of the 349 studies published before July 2016 identified in the database search, 40 were included (27 on healthy and 13 on obese subjects). Our systematic review suggests that the plasma level of ghrelin, the gut hormone promoting appetite, is positively correlated with activation in the pre-frontal cortex (PFC), amygdala and insula and negatively correlated with activation in subcortical areas such as the hypothalamus. In contrast, the plasma levels of glucose, insulin, leptin, PYY, GLP-1 affect the same brain regions conversely. Our study integrates previous investigations of the gut-brain matrix during food-intake and homeostatic regulation and may be of use for future meta-analyses of brain-gut interactions.
Topics: Appetite; Brain; Gastrointestinal Tract; Hormones; Humans; Satiation
PubMed: 28669754
DOI: 10.1016/j.neubiorev.2017.06.013 -
Nutrients Mar 2023Overweight and obesity in childhood and adolescence represents one of the most challenging public health problems of our century owing to its epidemic proportions and... (Review)
Review
Overweight and obesity in childhood and adolescence represents one of the most challenging public health problems of our century owing to its epidemic proportions and the associated significant morbidity, mortality, and increase in public health costs. The pathogenesis of polygenic obesity is multifactorial and is due to the interaction among genetic, epigenetic, and environmental factors. More than 1100 independent genetic loci associated with obesity traits have been currently identified, and there is great interest in the decoding of their biological functions and the gene-environment interaction. The present study aimed to systematically review the scientific evidence and to explore the relation of single-nucleotide polymorphisms (SNPs) and copy number variants (CNVs) with changes in body mass index (BMI) and other measures of body composition in children and adolescents with obesity, as well as their response to lifestyle interventions. Twenty-seven studies were included in the qualitative synthesis, which consisted of 7928 overweight/obese children and adolescents at different stages of pubertal development who underwent multidisciplinary management. The effect of polymorphisms in 92 different genes was assessed and revealed SNPs in 24 genetic loci significantly associated with BMI and/or body composition change, which contribute to the complex metabolic imbalance of obesity, including the regulation of appetite and energy balance, the homeostasis of glucose, lipid, and adipose tissue, as well as their interactions. The decoding of the genetic and molecular/cellular pathophysiology of obesity and the gene-environment interactions, alongside with the individual genotype, will enable us to design targeted and personalized preventive and management interventions for obesity early in life.
Topics: Adolescent; Child; Humans; Pediatric Obesity; Overweight; Body Mass Index; Genotype; Polymorphism, Single Nucleotide
PubMed: 36986146
DOI: 10.3390/nu15061416 -
International Journal of Molecular... Apr 2023Appetite dysregulation is one of the factors contributing to anorexia, bulimia nervosa, obesity, and diabetes. Essential oils or fragrant compounds have been proven to... (Review)
Review
Appetite dysregulation is one of the factors contributing to anorexia, bulimia nervosa, obesity, and diabetes. Essential oils or fragrant compounds have been proven to regulate food intake and energy expenditure; hence, this study aimed to summarize their effects on appetite and the underlying mechanisms. The PubMed and Web of Science databases were searched until July 2022. Only two of the 41 studies were performed clinically, and the remaining 39 used animal models. Oral administration was the most common route, and a dosage range of 100-2000 mg/kg for mice or 2-32 mg/kg for rats was applied, with a duration of 12 days to 4 weeks, followed by inhalation (10-10 mg/cage or 10-10 mg/cm within 1 h). Approximately 11 essential oil samples and 22 fragrant compounds were found to increase appetite, while 12 essential oils and seven compounds decreased appetite. These fragrant components can exert appetite-regulating effects via leptin resistance, the activity of sympathetic/parasympathetic nerves, or the mRNA expression of neuropeptide Y (NPY)/agouti-related protein (AgRP), cocaine- and amphetamine-regulated transcript (CART)/proopiomelanocortin (POMC) in the hypothalamus. Fragrance memory and cognitive processes may also play roles in appetite regulation. The findings of this study accentuate the potential of essential oils and fragrant compounds to regulate appetite and eating disorders.
Topics: Rats; Mice; Animals; Appetite; Oils, Volatile; Nerve Tissue Proteins; Neuropeptide Y; Hypothalamus; Leptin; Appetite Regulation; Agouti-Related Protein; Eating
PubMed: 37175666
DOI: 10.3390/ijms24097962 -
Frontiers in Neuroendocrinology Oct 2022Impaired hormonal regulation of appetite may contribute to higher cardiovascular risk in bipolar disorder (BD). We performed a systematic review and meta-analysis of... (Meta-Analysis)
Meta-Analysis Review
Impaired hormonal regulation of appetite may contribute to higher cardiovascular risk in bipolar disorder (BD). We performed a systematic review and meta-analysis of studies investigating peripheral blood levels of appetite-regulating hormones in BD and controls. A total of 32 studies were included. Leptin and insulin levels were significantly elevated in patients with BD during euthymia, but not in other mood states. Greater differences in the number of male participants between patients with BD and healthy controls were associated with higher effect size estimates for the levels of insulin. There were significant positive correlations of effect size estimates for the levels of adiponectin with the percentage of individuals with type I BD and duration of BD. Our findings point to the mechanisms underlying high rates of cardiometabolic comorbidities in BD. Moreover, they suggest that investigating hormonal regulation of appetite might help to understand differences in the neurobiology of BD types.
Topics: Humans; Male; Bipolar Disorder; Appetite; Adiponectin; Insulin
PubMed: 35792198
DOI: 10.1016/j.yfrne.2022.101013 -
Obesity Reviews : An Official Journal... Feb 2015Bariatric surgery continues to be remarkably efficient in treating obesity and type 2 diabetes mellitus and a debate has started whether it should remain the last resort... (Review)
Review
Bariatric surgery continues to be remarkably efficient in treating obesity and type 2 diabetes mellitus and a debate has started whether it should remain the last resort only or also be used for the prevention of metabolic diseases. Intense research efforts in humans and rodent models are underway to identify the critical mechanisms underlying the beneficial effects with a view towards non-surgical treatment options. This non-systematic review summarizes and interprets some of this literature, with an emphasis on changes in the controls of appetite. Contrary to earlier views, surgery-induced reduction of energy intake and subsequent weight loss appear to be the main drivers for rapid improvements of glycaemic control. The mechanisms responsible for suppression of appetite, particularly in the face of the large weight loss, are not well understood. Although a number of changes in food choice, taste functions, hedonic evaluation, motivation and self-control have been documented in both humans and rodents after surgery, their importance and relative contribution to diminished appetite has not yet been demonstrated. Furthermore, none of the major candidate mechanisms postulated in mediating surgery-induced changes from the gut and other organs to the brain, such as gut hormones and sensory neuronal pathways, have been confirmed yet. Future research efforts should focus on interventional rather than descriptive approaches in both humans and rodent models.
Topics: Animals; Appetite Regulation; Bariatric Surgery; Disease Models, Animal; Energy Intake; Energy Metabolism; Feeding Behavior; Gastrointestinal Hormones; Humans; Mice; Obesity; Rats; Weight Loss
PubMed: 25614206
DOI: 10.1111/obr.12258 -
Sleep Medicine Reviews Aug 2017Obesity and obstructive sleep apnea (OSA) have a reciprocal relationship. Sleep disruptions characteristic of OSA may promote behavioral, metabolic, and/or hormonal... (Review)
Review
UNLABELLED
Obesity and obstructive sleep apnea (OSA) have a reciprocal relationship. Sleep disruptions characteristic of OSA may promote behavioral, metabolic, and/or hormonal changes favoring weight gain and/or difficulty losing weight. The regulation of energy balance (EB), i.e., the relationship between energy intake (EI) and energy expenditure (EE), is complex and multi-factorial, involving food intake, hormonal regulation of hunger/satiety/appetite, and EE via metabolism and physical activity (PA). The current systematic review describes the literature on how OSA affects EB-related parameters. OSA is associated with a hormonal profile characterized by abnormally high leptin and ghrelin levels, which may encourage excess EI. Data on actual measures of food intake are lacking, and not sufficient to make conclusions. Resting metabolic rate appears elevated in OSA vs.
CONTROLS
Findings on PA are inconsistent, but may indicate a negative relationship with OSA severity that is modulated by daytime sleepiness and body weight. A speculative explanation for the positive EB in OSA is that the increased EE via metabolism induces an overcompensation in the drive for hunger/food intake, which is larger in magnitude than the rise in EI required to re-establish EB. Understanding how OSA affects EB-related parameters can help improve weight loss efforts in these patients.
Topics: Eating; Energy Metabolism; Exercise; Humans; Leptin; Obesity; Polysomnography; Sleep Apnea, Obstructive
PubMed: 27818084
DOI: 10.1016/j.smrv.2016.07.001 -
Journal of Diabetes and Metabolic... Jun 2020Previous studies have shown thylakoids, the membrane proteins which are extracted from green leaves like spinach, can induce satiety through homeostatic and... (Review)
Review
BACKGROUND
Previous studies have shown thylakoids, the membrane proteins which are extracted from green leaves like spinach, can induce satiety through homeostatic and non-homeostatic pathways. In this study, we reviewed the current human literature on thylakoids' characteristics and their relationship to satiety regulation and weight loss.
METHODS
A systematic search of literature published between January 1990 and May 2019 was conducted on the electronic databases; including WEB OF SCIENCE, Cochrane Library, MEDLINE, Scopus, and EMBASE databases. We included all clinical trials that addressed the effects of thylakoids or chloroplast intake on satiety and weight loss.
RESULTS
After excluding non-human studies, non-RCTs, duplications, studies with irrelevant data and interventions, eight studies were included in the qualitative synthesis. All studies supported this hypothesis that thylakoids reduce the feeling of hunger by increasing postprandial cholecystokinin and leptin and decreasing serum ghrelin, but the consequences of thylakoid intake on anthropometric characteristics were controversial.
CONCLUSION
In conclusion, our results may approve this postulation that receiving a thylakoid-enriched meal can decrease appetite and probably food intake in short term; however, more studies are needed to explore the effects of long term supplementation with thylakoids on weight loss in human subjects.
PubMed: 32550209
DOI: 10.1007/s40200-019-00443-w -
Nutrients Sep 2019The prevalence of obesity is increasing worldwide. Bioactive phytochemicals in food supplements are a trending approach to facilitate dieting and to improve patients'...
The prevalence of obesity is increasing worldwide. Bioactive phytochemicals in food supplements are a trending approach to facilitate dieting and to improve patients' adherence to reducing food and caloric intake. The aim of this systematic review was to assess efficacy and safety of the most commonly used bioactive phytochemicals with appetite/hunger-suppressing and/or satiety/fullness-increasing properties. To be eligible, studies needed to have included at least 10 patients per group aged 18 years or older with no serious health problems except for overweight or obesity. Of those studies, 32 met the inclusion criteria, in which 27 different plants were tested alone or as a combination, regarding their efficacy in suppressing appetite/hunger and/or increasing satiety/fullness. The plant extracts most tested were derived from (green tea), , and species. None of the plant extracts tested in several trials showed a consistent positive treatment effect. Furthermore, only a few adverse events were reported, but none serious. The findings revealed mostly inconclusive evidence that the tested bioactive phytochemicals are effective in suppressing appetite/hunger and/or increasing satiety/fullness. More systematic and high quality clinical studies are necessary to determine the benefits and safety of phytochemical complementary remedies for dampening the feeling of hunger during dieting.
Topics: Appetite Depressants; Appetite Regulation; Feeding Behavior; Female; Humans; Male; Obesity; Phytochemicals; Randomized Controlled Trials as Topic; Satiety Response; Treatment Outcome; Weight Loss
PubMed: 31533291
DOI: 10.3390/nu11092238 -
Appetite Jan 2022Individual differences in child eating self-regulation are associated with excess weight gain and may be explained, in part, by the family feeding environment and a... (Review)
Review
Individual differences in child eating self-regulation are associated with excess weight gain and may be explained, in part, by the family feeding environment and a child's general propensity to self-regulate outside of the context of eating (i.e., general self-regulation). Several studies have examined the associations between food parenting behaviors, child eating and general self-regulation, and child weight separately. However, there are a paucity of data on whether and how these factors interact to confer risk for weight gain in early childhood. The current systematic review identified 32 longitudinal studies that examined unidirectional or bidirectional associations among one or more of the following paths: food parenting behaviors and child eating self-regulation (path 1); child eating self-regulation and child weight (path 2); child eating self-regulation and child general self-regulation (path 3); food parenting behaviors and child general self-regulation (path 4); and child general self-regulation and child weight (path 5). Results indicated relationships of food parenting behaviors to child eating self-regulation, child weight to child eating self-regulation, and child general self-regulation to child weight. However, there were scant longitudinal data that examined paths 3 and 4. Further research on the developmental correlates of child eating self-regulation is needed to identify parent and child targets for early childhood obesity prevention.
Topics: Child; Child Behavior; Child, Preschool; Eating; Feeding Behavior; Humans; Parent-Child Relations; Parenting; Pediatric Obesity; Self-Control; Surveys and Questionnaires
PubMed: 34619243
DOI: 10.1016/j.appet.2021.105733 -
Nutricion Hospitalaria Jan 2018Malnutrition in children with cancer is a significant risk factor for negative outcomes, but in the clinical practice setting, it is difficult to pinpoint which factors... (Meta-Analysis)
Meta-Analysis Review
INTRODUCTION
Malnutrition in children with cancer is a significant risk factor for negative outcomes, but in the clinical practice setting, it is difficult to pinpoint which factors operate to cause substantial weight loss and malnutrition in a given patient. Appetite-related hormones like ghrelin and leptin are among possible mediators. However, only few studies have examined the role of these hormones in pediatric patients with cancer to date. Thus, the purpose of this study was to systematically review possible changes in the levels of appetite hormones, specially leptin and ghrelin, in pediatric patients with cancer.
MATERIAL AND METHODS
We systematically reviewed the literature using PubMed, Lilacs and Scielo, as well as manual bibliographical reference search of the studies. According to the Medical Subject Headings of the National Library of Medicine (MeSH), "childhood cancer", "ghrelin" and "leptin" were used as descriptors.
RESULTS
Fifteen studies were included in this systematic review published in English, from 2000 to 2015. A total of 863 patients were evaluated, ages ranging from 0 to 21 years, and most of the studies reported on children and adolescents with acute lymphoblastic leukemia (ALL) survivors. Most studies analyzed leptin levels; only two studies evaluated levels of ghrelin.
CONCLUSION
This review confirms that changes in the responses of the ghrelin and leptin hormones in children and adolescents with cancer are quite diverse, probably due to the different types of cancer observed, different treatments performed and biological characteristics of this age group.
Topics: Adolescent; Appetite Regulation; Child; Ghrelin; Hormones; Humans; Leptin; Neoplasms; Observational Studies as Topic
PubMed: 29565170
DOI: 10.20960/nh.1221