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Advances in Nutrition (Bethesda, Md.) Mar 2021Protein supplementation is an attractive strategy to prevent loss of muscle mass in older adults. However, it could be counterproductive due to adverse effects on... (Meta-Analysis)
Meta-Analysis
Protein supplementation is an attractive strategy to prevent loss of muscle mass in older adults. However, it could be counterproductive due to adverse effects on appetite. This systematic review and meta-analysis aimed to determine the effects of protein supplementation on appetite and/or energy intake (EI) in healthy older adults. MEDLINE, The Cochrane Library, CINAHL, and Web of Science were searched up to June 2020. Acute and longitudinal studies in healthy adults ≥60 y of age that reported effects of protein supplementation (through supplements or whole foods) compared with control and/or preintervention (for longitudinal studies) on appetite ratings, appetite-related peptides, and/or EI were included. Random-effects model meta-analysis was performed on EI, with other outcomes qualitatively reviewed. Twenty-two studies (9 acute, 13 longitudinal) were included, involving 857 participants (331 males, 526 females). In acute studies (n = 8), appetite ratings were suppressed in 7 out of 24 protein arms. For acute studies reporting EI (n = 7, n = 22 protein arms), test meal EI was reduced following protein preload compared with control [mean difference (MD): -164 kJ; 95% CI: -299, -29 kJ; P = 0.02]. However, when energy content of the supplement was accounted for, total EI was greater with protein compared with control (MD: 649 kJ; 95% CI: 438, 861 kJ; P < 0.00001). Longitudinal studies (n = 12 protein arms) showed a higher protein intake (MD: 0.29 g ⋅ kg-1 ⋅ d-1; 95% CI: 0.14, 0.45 g ⋅ kg-1 ⋅ d-1; P < 0.001) and no difference in daily EI between protein and control groups at the end of trials (MD: -54 kJ/d; 95% CI: -300, 193 kJ/d; P = 0.67). While appetite ratings may be suppressed with acute protein supplementation, there is either a positive effect or no effect on total EI in acute and longitudinal studies, respectively. Therefore, protein supplementation may represent an effective solution to increase protein intakes in healthy older adults without compromising EI through appetite suppression. This trial was registered at PROSPERO as https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42019125771 (CRD42019125771).
Topics: Aged; Appetite; Appetite Regulation; Dietary Supplements; Energy Intake; Female; Humans; Male; Meals
PubMed: 33037427
DOI: 10.1093/advances/nmaa115 -
Critical Reviews in Food Science and... 2021Short chain fatty acids (SCFA) are produced by bacterial fermentation of non-digestible carbohydrates (NDC) and have many potential tissue and SCFA specific actions,...
Short chain fatty acids (SCFA) are produced by bacterial fermentation of non-digestible carbohydrates (NDC) and have many potential tissue and SCFA specific actions, from providing fuel for colonic cells to appetite regulation. Many studies have described the fermentation of different carbohydrates, often using in vitro batch culture. As evidence-based critical evaluation of substrates selectively promoting production of individual SCFA is lacking, we performed a systematic scoping literature review. Databases were searched to identify relevant papers published between 1900 and 12/06/2016. Search terms included In vitro and In vitro Articles were considered for essential criteria allowing equivalent comparison of SCFA between NDC. Seventy seven articles were included in the final analysis examining 29 different carbohydrates. After 24-hour fermentation, galacto-oligosaccharide ranked highest for butyrate and total SCFA production and second for acetate production. Rhamnose ranked highest for propionate production. The lowest SCFA production was observed for kiwi fiber, polydextrose, and cellulose. This review demonstrates that choosing a substrate to selectively enhance a specific SCFA is difficult, and the molar proportion of each SCFA produced by individual substrates may be misleading. Instead the rate and ratio of SCFA production should be evaluated in parallel.
Topics: Butyrates; Carbohydrate Metabolism; Carbohydrates; Dietary Fiber; Fatty Acids, Volatile; Feces; Fermentation; Gastrointestinal Microbiome; Humans
PubMed: 32865002
DOI: 10.1080/10408398.2020.1809991 -
Nutrients Aug 2020Evidence synthesizing the effects of acute body water losses on various markers of glycemic regulation, appetite, metabolism, and stress is lacking. Thus, the purpose of... (Meta-Analysis)
Meta-Analysis
Evidence synthesizing the effects of acute body water losses on various markers of glycemic regulation, appetite, metabolism, and stress is lacking. Thus, the purpose of this review was to summarize the response of various hormonal changes involved in these physiologic functions to dehydration. A comprehensive literature search for peer-reviewed research in the databases PubMed, Scopus, CINAHL, and SportDiscus was conducted. Studies were included if they contained samples of adults (>18 years) and experimentally induced dehydration as measured by acute body mass loss. Twenty-one articles were eligible for inclusion. Findings suggested cortisol is significantly elevated with hypohydration (standard mean difference [SMD] = 1.12, 95% CI [0.583, 1.67], < 0.0001). Testosterone was significantly lower in studies where hypohydration was accompanied by caloric restriction (SMD= -1.04, 95% CI [-1.93, -0.14], = 0.02), however, there were no changes in testosterone in studies examining hypohydration alone (SMD = -0.17, 95% CI [-0.51 0.16], = 0.30). Insulin and ghrelin were unaffected by acute total body water losses. Acute hypohydration increases markers of catabolism but has a negligible effect on markers of glycemic regulation, appetite, anabolism and stress. Given the brevity of existing research, further research is needed to determine the impact of hydration on glucagon, leptin, peptide YY and the subsequent outcomes relevant to both health and performance.
Topics: Adolescent; Adult; Appetite; Blood Glucose; Caloric Restriction; Dehydration; Female; Ghrelin; Humans; Hydrocortisone; Leptin; Male; Peptide YY; Stress, Physiological; Testosterone; Young Adult; alpha-Amylases
PubMed: 32825404
DOI: 10.3390/nu12092526 -
Physiology & Behavior Nov 2020High-protein diets are considered as useful diets for weight loss programs. We collected randomized controlled trials that evaluated the effect of protein on appetite... (Meta-Analysis)
Meta-Analysis Review
Effect of short- and long-term protein consumption on appetite and appetite-regulating gastrointestinal hormones, a systematic review and meta-analysis of randomized controlled trials.
AIM
High-protein diets are considered as useful diets for weight loss programs. We collected randomized controlled trials that evaluated the effect of protein on appetite and gastrointestinal hormones involved in appetite regulation.
METHODS
Trials were included if participants were healthy adults and isocaloric treatments were used in control and treatment arms. Random-effects model was used to calculate mean difference and 95% confidence intervals.
RESULTS
In total, 49 publications for acute and 19 articles for long-term effect of protein were included. In acute interventions, protein decreased hunger (-7 mm visual analogue scale (VAS), P<0.001), desire to eat (-5 mm, P = 0.045), and prospective food consumption (-5 mm, P = 0.001) and increased fullness (10 mm, P<0.001) and satiety (4 mm, P<0.001). There was also a decrease in ghrelin (-20 pg/ml, P<0.001) and increase in cholecystokinin (30 pg/ml, P<0.001) and glucagon-like peptide-1 (GLP-1) (21 ng/ml, P<0.001), but no change in gastric inhibitory polypeptide and peptide YY was observed. Appetite markers were affected by protein doses < 35 g but ghrelin, cholecystokinin, and GLP-1 changed significantly after doses ≥ 35 g. Long-term ingestion of protein did not affect these outcomes, except for GLP-1 which showed a significant decrease.
CONCLUSION
Results of this meta-analysis showed that acute ingestion of protein suppresses appetite, decreases ghrelin, and augments cholecystokinin and GLP-1. Results of long-term trials are inconclusive and further trials are required before a clear and sound conclusion on these trials could be made.
Topics: Adult; Appetite; Cholecystokinin; Dietary Proteins; Energy Intake; Gastrointestinal Hormones; Ghrelin; Humans; Peptide YY; Prospective Studies; Randomized Controlled Trials as Topic
PubMed: 32768415
DOI: 10.1016/j.physbeh.2020.113123 -
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 -
International Journal of Food Sciences... Nov 2020Studies have shown the effects of chocolate-based products on appetite-related indicators; however, the results of these studies are equivocal. Thus, the aim of the... (Meta-Analysis)
Meta-Analysis
Studies have shown the effects of chocolate-based products on appetite-related indicators; however, the results of these studies are equivocal. Thus, the aim of the present study was to conduct a systematic review of studies investigating the acute and long-term response of appetite-related hormones to chocolate intake in adults. A systematic search of MEDLINE and EMBASE for published studies, in English, was performed from inception up to November 2018. It appears that ghrelin and leptin are not responsible for the satiating effect of chocolate products. Gastric infusion of milk chocolate elicited a greater increase in cholecystokinin (CCK), in comparison with oral ingestion of milk chocolate and gastric infusion of non-caloric products. Moreover, viscosity seems to have no effect on active CCK and glucagon-like peptide-1. Due to the heterogeneity between studies, limited sample, low quality of evidence, and substantial variation in methods and chocolate products, caution is suggested in interpreting these results.
Topics: Appetite; Chocolate; Gene Expression Regulation; Hormones; Humans
PubMed: 32126864
DOI: 10.1080/09637486.2020.1734543 -
Obesity Science & Practice Dec 2019Pharmacological interventions to aid weight loss have historically targeted either appetite suppression or increased metabolic rate. Brown adipose tissue (BAT) possesses... (Review)
Review
Pharmacological interventions to aid weight loss have historically targeted either appetite suppression or increased metabolic rate. Brown adipose tissue (BAT) possesses the capacity to expend energy in a futile cycle, thus increasing basal metabolic rate. In animal models, oestrogen has been implicated in the regulation of body weight, and it is hypothesized that oestrogen is acting by modulating BAT metabolism. A systematic search was performed, to identify research articles implementing in vivo oestrogen-related interventions and reporting outcome measures that provide direct or indirect measures of BAT metabolism. Meta-analyses were conducted where sufficient data were available. The final library of 67 articles were predominantly in rodent models and provided mostly indirect measures of BAT metabolism. Results of this review found that oestrogen's effects on body weight, in rats and possibly mice, are likely facilitated by both metabolic and appetitive mechanisms but are largely only found in ovariectomized models. There is a need for further studies to clarify the potential effects of oestrogen on BAT metabolism in gonad-intact and castrated male animal models.
PubMed: 31890250
DOI: 10.1002/osp4.368 -
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 -
Nutrients Aug 2019Breast milk is characterized by a dynamic and complex composition which includes hormones and other bioactive components that could influence infant growth, development,...
Breast milk is characterized by a dynamic and complex composition which includes hormones and other bioactive components that could influence infant growth, development, and optimize health. Among the several beneficial effects associated with prolonged breastfeeding, a 13% decrease in the risk of overweight and obesity has been reported. Recent research has focused on breast milk hormones contributing to the appetite and energy balance regulation and adiposity. Accordingly, we conducted a literature systematic review with the aim to provide an update on the effect of leptin, ghrelin, Insulin Growth Factor 1, adiponectin, and insulin on infants' and children's growth and body composition. The revised literature reveals contrasting findings concerning the potential role of all these hormones on modeling growth and fat mass apposition and health outcomes later in life. Further studies are needed to gain further insight into the specific role of these bioactive components in metabolic pathways related to body composition. This could help gain a further insight on infants' growth, both in physiological and pathological settings.
Topics: Child Development; Female; Hormones; Humans; Infant; Milk, Human
PubMed: 31395844
DOI: 10.3390/nu11081845 -
Prostate Cancer and Prostatic Diseases Mar 2020Obesity has been proposed as a risk factor for prostate cancer (PCa). In obesity, serum levels of the appetite-regulating hormones-leptin, adiponectin, and... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Obesity has been proposed as a risk factor for prostate cancer (PCa). In obesity, serum levels of the appetite-regulating hormones-leptin, adiponectin, and ghrelin-become deregulated.
OBJECTIVE
To explore whether serum levels of appetite-regulating hormones associate with the incidence of PCa, the incidence of advanced disease, or PCa-specific mortality.
METHODS
PRISMA guidelines were followed. A systematic search for relevant articles published until March 2019 was performed using the databases PubMed, EMBASE, and Web of Science. Observational studies with data on serum levels of leptin, adiponectin, or ghrelin and PCa outcome were included. Meta-analysis was used to combine risk estimates. Meta-relative risks (mRRs) were calculated using random effects models. When available, raw data was pooled. Publication bias was assessed by funnel plot and Begg's test.
RESULTS
Thirty-five studies were eligible for inclusion. The qualitative analysis indicated that leptin was not consistently associated with any PCa outcome, although several cohorts reported decreased adiponectin levels in men who later developed advanced PCa. Based on the meta-analysis, there was no significant effect of leptin on PCa incidence (mRR = 0.93 (95% CI 0.75-1.16), p = 0.52) or advanced PCa (mRR = 0.90 (95% CI 0.74-1.10), p = 0.30). There were insufficient studies to estimate the mRR of PCa incidence for men with the highest levels of adiponectin. The combined risk of advanced PCa for men with the highest levels of adiponectin was reduced but did not reach significance (mRR = 0.81 (95% CI 0.61-1.08), p = 0.15).
CONCLUSIONS
The current evidence does not suggest an association between leptin and PCa outcome. However, there may be an inverse association between adiponectin and the incidence of advanced PCa that should be investigated by further studies. Serum ghrelin has not been largely investigated.
Topics: Adiponectin; Appetite; Disease Susceptibility; Epithelial Cells; Gene Expression Regulation; Ghrelin; Humans; Leptin; Male; Obesity; Peptide Hormones; Prostatic Neoplasms; Publication Bias; Signal Transduction
PubMed: 31147627
DOI: 10.1038/s41391-019-0154-1