β-Glucan-enriched bread reduces energy intake and modifies plasma ghrelin and peptide YY concentrations in the short term Dose-Dependent Effects of Randomized Intraduodenal Whey-Protein Loads on Glucose, Gut Hormone, and Amino Acid Concentrations in Healthy Older and Younger Men Reproducibility of energy intake, gastric emptying, blood glucose, plasma insulin and cholecystokinin responses in healthy young males. Dose-dependent effects of cholecystokinin-8 on antropyloroduodenal motility, gastrointestinal hormones, appetite, and energy intake in healthy men. Prebiotic supplementation improves appetite control in children with overweight and obesity: a randomized controlled trial. Energy intake and appetite are related to antral area in healthy young and older subjects. Influence of prolonged treadmill running on appetite, energy intake and circulating concentrations of acylated ghrelin Breaking up prolonged sitting time with walking does not affect appetite or gut hormone concentrations but does induce an energy deficit and suppresses postprandial glycaemia in sedentary adults. Acute ingestion of resistant starch reduces food intake in healthy adults. Mild dehydration does not reduce postexercise appetite or energy intake. Ghrelin enhances appetite and increases food intake in humans. Serum brain-derived neurotrophic factor is associated with reduced appetite in healthy older adults The impact of oligofructose on stimulation of gut hormones, appetite regulation and adiposity. Food form and portion size affect postprandial appetite sensations and hormonal responses in healthy, nonobese, older adults. Effects of High-Intensity Intermittent Exercise Training on Appetite Regulation. Postprandial effects of polydextrose on satiety hormone responses and subjective feelings of appetite in obese participants Effects of exercise on energy-regulating hormones and appetite in men and women. Oral processing effort, appetite and acute energy intake in lean and obese adults Effects of age on concentrations of plasma cholecystokinin, glucagon-like peptide 1, and peptide YY and their relation to appetite and pyloric motility. Effect of short-term high dietary calcium intake on 24-h energy expenditure, fat oxidation, and fecal fat excretion Systematic review of the evidence for sustained efficacy of dietary interventions for reducing appetite or energy intake. Differential effects of dairy snacks on appetite, but not overall energy intake. Effects of oligofructose on appetite profile, glucagon-like peptide 1 and peptide YY3-36 concentrations and energy intake.
Dietary fibre consumption may help to control appetite and to reduce calorie intake . Underlying molecular mechanisms were not fully investigated . The aim of this study was to evaluate the effect of barley beta-glucans on short-term appetite and on satiety-related hormones in healthy subjects . Fourteen volunteers were selected and r and omly assigned to have isocaloric breakfasts including a 3 % beta-glucan-enriched bread ( betaGB ) or a control bread ( CB ) . Post-breakfast individual self-records of appetite ratings and measure of calorie intake at an ad libitum lunch as well as measure of blood glucose , insulin , ghrelin and PYY concentrations , were performed . betaGB determined a significant higher reduction of hunger and increase of fullness and satiety than CB . Accordingly , a 19 % reduction of energy intake at lunch subsequent to betaGB consumption compared to CB , was recorded . A 23 % lower AUC(60 - 180 ) of plasma ghrelin and a 16 % higher total AUC of PYY response after betaGB than CB consumption , independent from insulin response , was found . Glucose response was also blunted by betaGB vs CB . Barley beta-glucans were able to control appetite in the short term by modulating sensations and reducing energy intake . Data suggested for the first time that satiety effect of beta-glucans are mediated by ghrelin and PYY Protein-rich supplements are used widely for the prevention and management of malnutrition in older people . We have reported that healthy older , compared to younger , adults have less suppression of energy intake by whey-protein — effects on appetite-related hormones are unknown . The objective was to determine the effects of intraduodenally administered whey-protein on glucose , gut hormone , and amino acid concentrations , and their relation to subsequent ad libitum energy intake at a buffet meal , in healthy older and younger men .  Hydrolyzed whey-protein ( 30 kcal , 90 kcal , and 180 kcal ) and a saline control ( ~0 kcal ) were infused intraduodenally for 60 min in 10 younger ( 19–29 years , 73 ± 2 kg , 22 ± 1 kg/m2 ) and 10 older ( 68–81 years , 79 ± 2 kg , 26 ± 1 kg/m2 ) healthy men in a r and omized , double-blind fashion . Plasma insulin , glucagon , gastric inhibitory peptide ( GIP ) , glucagon-like peptide-1 ( GLP-1 ) , peptide tyrosine-tyrosine ( PYY ) , and amino acid concentrations , but not blood glucose , increased , while ghrelin decreased during the whey-protein infusions . Plasma GIP concentrations were greater in older than younger men . Energy intake correlated positively with plasma ghrelin and negatively with insulin , glucagon , GIP , GLP-1 , PYY , and amino acids concentrations ( p < 0.05 ) . In conclusion , intraduodenal whey-protein infusions result ed in increased GIP and comparable ghrelin , insulin , glucagon , GIP , GLP-1 , PYY , and amino acid responses in healthy older and younger men , which correlated to subsequent energy intake Gastric emptying , as well as intragastric meal distribution , and gastrointestinal hormones , including cholecystokinin ( CCK ) , play an important role in appetite regulation . The evaluation of gastrointestinal factors regulating food intake is commonly performed in healthy , lean , young male participants . It has , however , been suggested that there is a marked interindividual variability in the effects of nutrient ' preloads ' on energy intake in this group . Whether there is significant intraindividual variation in acute energy intake after a nutrient preload , and , if so , how this relates to day-to-day differences in gastric emptying and gastrointestinal hormone release , is unclear . The purpose of the present paper is to evaluate the hypothesis that energy intake after a nutrient preload would be reproducible and associated with reproducible patterns of gastric emptying , intragastric distribution and gastrointestinal hormone release .  Fifteen healthy men ( age 25 ( sem 5 ) years ) consumed a glucose preload ( 50 g glucose in 300 ml water ; 815 kJ ) on three occasions . Gastric emptying and intragastric meal distribution ( using  three-dimensional ultrasound )  , blood glucose , plasma insulin and CCK concentrations and appetite perceptions were evaluated over 90 min , and energy intake from a cold buffet-style meal was then quantified . Energy intake was highly reproducible within individuals between visits ( intraclass correlation coefficient , ri = 0.9 ) . Gastric emptying , intragastric meal distribution , blood glucose , plasma insulin and CCK concentrations and appetite perceptions did not differ between visits ( ri>0.7 for all ) . In healthy males , energy intake is highly reproducible , at least in the short term , and is associated with reproducible patterns of gastric emptying , glycaemia , insulinaemia and CCK release CCK mediates the effects of nutrients on gastrointestinal motility and appetite . Intravenously administered CCK stimulates pyloric pressures , increases plasma PYY , and suppresses ghrelin , all of which may be important in the regulation of appetite and energy intake . The dose-related effects of exogenous CCK on gastrointestinal motility and gut hormone release , and the relationships between these effects and those on energy intake , are uncertain . We hypothesized that 1 ) intravenous CCK-8 would have dose-dependent effects on antropyloroduodenal ( APD ) pressures , plasma PYY and ghrelin concentrations , appetite , and energy intake and 2 ) the suppression of energy intake by CCK-8 would be related to the stimulation of pyloric motility . Ten healthy men ( age 26 + /- 2 yr ) were studied on four separate occasions in double-blind , r and omized fashion . APD pressures , plasma PYY and ghrelin , and appetite were measured during 120-min intravenous infusions of 1 ) saline ( " control " ) or 2 ) CCK-8 at 0.33 ( " CCK0.33 " ) , 3 ) 0.66 ( " CCK0.66 " ) , or 4 ) 2.0 ( " CCK2.0 " ) ng.kg(-1).min(-1 ) . After 90 min , energy intake at a buffet meal was quantified . CCK-8 dose-dependently stimulated phasic and tonic pyloric pressures and plasma PYY concentrations ( r > 0.70 , P < 0.05 ) and reduced desire to eat and energy intake ( r > -0.60 , P < 0.05 ) without inducing nausea . There were relationships between basal pyloric pressure and isolated pyloric pressure waves ( IPPW ) with plasma CCK ( r > 0.50 , P < 0.01 ) and between energy intake with IPPW ( r = -0.70 , P < 0.05 ) . Therefore , our study demonstrates that exogenous CCK-8 has dose-related effects on APD motility , plasma PYY , desire to eat , and energy intake and suggests that the suppression of energy intake is related to the stimulation of IPPW Background : Prebiotics have been shown to improve satiety in adults with overweight and obesity ; however , studies in children are limited . Objective : We examined the effects of prebiotic supplementation on appetite control and energy intake in children with overweight and obesity . Design : This study was a r and omized , double-blind , placebo-controlled trial . Forty-two boys and girls , ages 7 - 12 y , with a body mass index ( BMI ) of ≥85th percentile were r and omly assigned to 8 g oligofructose-enriched inulin/d or placebo ( maltodextrin ) for 16 wk . Objective measures of appetite included energy intake at an ad libitum breakfast buffet , 3-d food records , and fasting satiety hormone concentrations . Subjective appetite ratings were obtained from visual analog scales before and after the breakfast . Children 's Eating Behavior Question naires were also completed by caregivers . Results : Compared with placebo , prebiotic intake result ed in significantly higher feelings of fullness ( P = 0.04 ) and lower prospect i ve food consumption ( P = 0.03 ) at the breakfast buffet at 16 wk compared with baseline . Compared with placebo , prebiotic supplementation significantly reduced energy intake at the week 16 breakfast buffet in 11- and 12-y-olds ( P = 0.04 ) but not in 7- to 10-y-olds . Fasting adiponectin ( P = 0.04 ) and ghrelin ( P = 0.03 ) increased at 16 wk with the prebiotic compared with placebo . In intent-to-treat analysis , there was a trend for prebiotic supplementation to reduce BMI z score to a greater extent than placebo ( -3.4 % ; P = 0.09 ) and a significant -3.8 % reduction in per- protocol analysis ( P = 0.043 ) . Conclusions : Independent of other lifestyle changes , prebiotic supplementation in children with overweight and  obesity improved subjective appetite ratings . This translated into reduced energy intake in a breakfast buffet in older but not in younger children . This simple dietary change has the potential to help with appetite regulation in children with obesity . This trial was registered at clinical trials.gov as NCT02125955 BACKGROUND Gastric distension reduces food intake , and antral , rather than proximal , gastric distension may be the dominant mechanism in the induction of appetite-related sensations . Healthy aging is associated with reduced appetite . OBJECTIVE We examined the effects of different energy preloads on appetite , plasma cholecystokinin , antral area , and subsequent energy intake in healthy older and young subjects . DESIGN On 3 separate days , 12 young and 12 older subjects consumed 400 mL of a drink containing either 0 kcal ( water ) , 250 kcal , or 750 kcal 70 min before a buffet-style meal . RESULTS Hunger was less in the older than in the young subjects ( P < 0.001 ) . Both nutrient preloads reduced hunger and increased fullness more than did water ( P < 0.02 ) , and older subjects were more full than were the young ( P < 0.05 ) . Antral area was greater after the nutrient preloads than after water ( P = 0.001 ) and greater in the older than in the young subjects ( P = 0.005 ) . In both groups , food intake was suppressed in an energy-dependent manner ( P = 0.008 ) . Plasma cholecystokinin was greater in the older than in the young subjects ( P = 0.003 ) . Immediately before the meal , hunger ( r = -0.59 ) and energy intake ( r = -0.90 ) were inversely related and fullness ( r = 0.66 ) was directly related to antral area ( all : P < 0.001 ) . Antral area , but not plasma cholecystokinin , was a predictor of subsequent energy intake . CONCLUSION In healthy young and older subjects , the suppression of subsequent energy intake by a liquid preload is nutrient dependent and comparable , and both satiation and satiety are related to antral area and ( presumably ) antral distension The effects of prolonged treadmill running on appetite , energy intake and acylated ghrelin ( an appetite stimulating hormone ) were examined in 9 healthy males over the course of 24h . Participants completed 2 experimental trials ( exercise and control ) in a r and omised-crossover fashion . In the exercise trial participants ran for 90 min at 68.8 + or - 0.8 % of maximum oxygen uptake followed by 8.5 h of rest . Participants returned to the laboratory on the following morning to provide a fasting blood sample and ratings of appetite ( 24 h measurement ) . No exercise was performed on the control trial . Appetite was measured within the laboratory using visual analogue scales and energy intake was assessed from ad libitum buffet meals . Acylated ghrelin was determined from plasma using an ELISA assay . Exercise  transiently suppressed appetite and acylated ghrelin but each remained no different from control values in the hours afterwards . Furthermore , despite participants expending 5324 kJ during exercise there was no compensatory increase in energy intake ( 24 h energy intake ; control 17,191 kJ , exercise 17,606 kJ ) . These findings suggest that large energy deficits induced by exercise do not lead to acute compensatory responses in appetite , energy intake or acylated ghrelin Breaking up periods of prolonged sitting can negate harmful metabolic effects but the influence on appetite and gut hormones is not understood and is investigated in this study . Thirteen sedentary ( 7 female ) participants undertook three 5-h trials in r and om order : ( i ) uninterrupted sitting ( SIT ) , ( ii ) seated with 2-min bouts of light-intensity walking every 20 min ( SIT + LA ) , and ( iii ) seated with 2-min bouts of moderate-intensity walking every 20 min ( SIT + MA ) . A st and ardised test drink was provided at the start of each trial and an ad libitum pasta test meal provided at the end of each trial . Subjective appetite ratings and plasma acylated ghrelin , peptide YY , insulin , and glucose were measured at regular intervals . Area under the curve ( AUC ) was calculated for each variable . AUC values for appetite and gut hormone concentrations were unaffected in the activity breaks conditions compared with uninterrupted sitting ( linear mixed modelling : p > 0.05 ) . Glucose AUC was lower in SIT + MA than in SIT + LA ( p = 0.004 ) and SIT ( p = 0.055 ) . There was no difference in absolute ad libitum energy intake between conditions ( p > 0.05 ) ; however , relative energy intake was lower in SIT + LA ( 39 % ; p = 0.011 ) and SIT + MA ( 120 % ; p < 0.001 ) than in SIT . In conclusion , breaking up prolonged sitting does not alter appetite and gut hormone responses to a meal over a 5-h period . Increased energy expenditure from activity breaks could promote an energy deficit that is not compensated for in a subsequent meal Resistant starch ( RS ) , a non-viscous dietary fibre , may have postpr and ial effects on appetite regulation and metabolism , although the exact effects and mechanisms are unknown . An acute r and omised , single-blind crossover study , aim ed to determine the effects of consumption of 48 g RS on appetite compared to energy and available carbohydrate-matched placebo .  Twenty young healthy adult males consumed either 48 g RS or the placebo divided equally between two mixed meals on two separate occasions . Effects on appetite were assessed , using an ad libitum test meal and 24-h diet diaries for energy intake , and using visual analogue scales for subjective measures . Changes to postpr and ial glucose , insulin and C-peptide were also assessed . There was a significantly lower energy intake following the RS supplement compared to the placebo supplement at both the ad libitum test meal ( 5241 ( sem 313 ) v. 5606 ( sem 345 ) kJ , P = 0.033 ) and over the 24 h ( 12 603 ( sem 519 ) v. 13 949 ( sem 755 ) kJ , P = 0.044 ) . However , there was no associated effect on subjective appetite measures . Postpr and ial plasma glucose concentrations were not significantly different between supplements , but there was a significantly lower postpr and ial insulin response following the RS supplement ( P = 0.029 ) . The corresponding C-peptide concentrations were not significantly different , although the ratio of C-peptide to insulin was higher following the RS supplement compared to placebo ( P = 0.059 ) . These results suggest that consumption of 48 g RS , over a 24-h period , may be useful in the management of the metabolic syndrome and appetite . Further studies are required to determine the exact mechanisms PURPOSE It has now been established that exercise performed under various environmental conditions may affect acute energy intake and appetite-related hormones . The exact mechanism linking acute energy intake and exercise remains unknown , although indirect evidence suggests a possible role for hydration status . Therefore , the purpose of this study was to investigate the interaction of exercise and hydration status on subsequent energy intake and appetite-related hormones . METHODS In a r and omized , counterbalanced design , 10 physically active males completed three experimental trials in a fasted state : exercise when hydrated ( 0%-1 % of body mass ) , exercise when dehydrated ( -1 % to -2 % of body mass ) , and a hydrated resting control . Exercise consisted of treadmill running for 45 min at 70 % VO2peak . Participants were then given access to a buffet-style breakfast from which they could consume ad libitum . Blood was sample d regularly during trials for appetite-related hormones . RESULTS There were no significant differences in total energy intake between trials ( P = 0.491 ) ; however , relative energy intake was significantly higher in the control ( 4839 ± 415 kJ , P < 0.001 ) compared to hydrated ( 1749 ± 403 kJ ) and dehydrated exercise ( 1656 ± 413 kJ ) conditions . Exercise performed in a dehydrated state result ed in significantly lower concentrations of ghrelin compared with control ( P = 0.045 ) and hydrated exercise conditions ( P = 0.014 ) . CONCLUSIONS Exercise significantly decreased relative energy intake compared with resting control ; however , energy intake ( relative and total ) was no different between the exercise conditions ( dehydrated vs hydrated ) . Despite similar energy intake between trials , exercise in a dehydrated state result ed in a significantly lower concentration of ghrelin , a hormone responsible for stimulating appetite Ghrelin is a recently identified endogenous lig and for the growth hormone secretagogue receptor . It is synthesized predominantly in the stomach and found in the circulation of healthy humans . Ghrelin has been shown to promote increased food intake , weight gain and adiposity in rodents . The effect of ghrelin on appetite and food intake in man has not been determined . We investigated the effects of intravenous ghrelin ( 5.0 pmol/kg/min ) or saline infusion on appetite and food intake in a r and omised double-blind cross-over study in nine healthy volunteers . There was a clear-cut increase in energy consumed by every individual from a free-choice buffet ( mean increase 28 + /- 3.9 % , p<0.001 ) during ghrelin compared with saline infusion . Visual analogue scores for appetite were greater during ghrelin compared to saline infusion . Ghrelin had no effect on gastric emptying as assessed by the paracetamol absorption test . Ghrelin is the first circulating hormone demonstrated to stimulate food intake in man . Endogenous ghrelin is a potentially important new regulator of the complex systems controlling food intake and body weight Objective : Loss of appetite and body mass are common in older adults and are associated with negative consequences . Research indicates that these processes likely involve increases in serum brain-derived neurotrophic factor ( BDNF ) . Animal and human models demonstrate that BDNF may serve a regulatory function in food intake , but no study has addressed the possibility that BDNF may be involved in appetite reduction and loss of body mass in older adults . Design and Participants : 34 older adults without significant neurological or psychiatric history underwent fasting blood draw and measurement of body composition .  Appetite and eating behavior were assessed by question naire and related to serum BDNF levels . Results : Partial correlations showed serum BDNF levels were inversely related to appetite ( r = −.38 , p = .02 ) . No significant correlations emerged between serum BDNF and age , diet , or body composition . Conclusions : The current study extends past work and shows that BDNF is associated with appetite in healthy older adults . Further work is needed to clarify mechanisms for these findings , particularly prospect i ve studies OBJECTIVE To investigate the effect of nutrient stimulation of gut hormones by oligofructose supplementation on appetite , energy intake ( EI ) , body weight ( BW ) and adiposity in overweight and obese volunteers . METHODS In a parallel , single-blind and placebo-controlled study , 22 healthy overweight and obese volunteers were r and omly allocated to receive 30 g day(-1 ) oligofructose or cellulose for 6 weeks following a 2-week run-in . Subjective appetite and side effect scores , breath hydrogen , serum short chain fatty acids ( SCFAs ) , plasma gut hormones , glucose and insulin concentrations , EI , BW and adiposity were quantified at baseline and post-supplementation . RESULTS Oligofructose increased breath hydrogen ( P < 0.0001 ) , late acetate concentrations ( P = 0.024 ) , tended to increase total area under the curve (tAUC)420 mins peptide YY ( PYY ) ( P = 0.056 ) and reduced tAUC450 mins hunger ( P = 0.034 ) and motivation to eat ( P = 0.013 ) when compared with cellulose . However , there was no significant difference between the groups in other parameters although within group analyses showed an increase in glucagon-like peptide 1 ( GLP-1 ) ( P = 0.006 ) in the cellulose group and a decrease in EI during ad libitum meal in both groups . CONCLUSIONS Oligofructose increased plasma PYY concentrations and suppressed appetite , while cellulose increased GLP-1 concentrations . EI decreased in both groups . However , these positive effects did not translate into changes in BW or adiposity Data are limited concerning the dietary factors that influence appetite control in older adults . This study examined the effects of food form and portion size on appetite in 43 older adults ( age : 72 + /- 1 years ; BMI : 25.6 + /- 0.3 kg/m(2 ) ) . Subjects were assigned to groups based on portion size of the test meal ( 12.5 % ( n = 18 ) vs. 25 % ( n = 25 ) of estimated energy need ) . Subjects r and omly consumed , on two separate days , the respective solid or beverage test meal .  Appetite sensations and hormonal responses were measured over 4 h. Main effects of food form ( P < 0.05 ) and /or portion size ( P < 0.05 ) were observed for each appetite sensation . Postpr and ial hunger and desire to eat were greater following beverage vs. solid meal ( between 12.5 % vs. 25 % ) , whereas fullness was lower after beverage vs. solid meal ( P < 0.05 ) . Main effects of food form and /or portion size were observed for glucose , insulin , and ghrelin . Postpr and ial glucose and insulin concentrations were lower after beverage vs. solid meal ( between 12.5 % vs. 25 % ; all comparisons , P < 0.05 ) whereas beverage meal led to greater 4-h ghrelin vs. solid meal ( P = 0.09 ) . No main effects were observed for glucagon-like peptide-1 ( GLP-1 ) or cholecystokinin ( CCK ) . When adjusting for age , food form remained significant for postpr and ial hunger and fullness ; portion size remained significant for postpr and ial glucose . Greater hunger and reduced satiety with accompanying glucose , insulin , and ghrelin following the beverage vs. solid meals , and to some extent , in smaller vs. larger portions suggest that appetite control is influenced by food form and portion size in older adults . These findings may enhance the development of appropriate dietary strategies that help to regulate energy balance OBJECTIVE An acute bout of high-intensity intermittent exercise suppresses ad libitum energy intake at the postexercise meal . The present study examined the effects of 12 wk of high-intensity intermittent exercise training ( HIIT ) compared with moderate-intensity continuous exercise training ( MICT ) on appetite regulation . METHODS Thirty overweight inactive men ( body mass index , 27.2 ± 1.3 kg·m(-2 ) ; V˙O2peak , 35.3 ± 5.3 mL·kg(-1)·min(-1 ) were r and omized to either HIIT or MICT  ( involving 12 wk of training , three sessions per week ) or a control group ( CON ) ( n = 10 per group ) . Ad libitum energy intake from a laboratory test meal was assessed after both a low-energy ( 847 kJ ) and a high-energy preload ( 2438 kJ ) before and  after the intervention . Perceived appetite and appetite-related blood variables were also measured . RESULTS There was no significant effect of the intervention period on energy intake at the test meal after the two different preloads ( P ≥ 0.05 ) . However , the 95 % confidence interval indicated a clinical ly meaningful decrease in energy intake after the high-energy preload compared with the low-energy preload in response to HIIT ( 516 ± 395 kJ decrease ) , but not for MICT or CON , suggesting improved appetite regulation . This was not associated with alterations in the perception of appetite or the circulating concentration of a number of appetite-related peptides or metabolites , although insulin sensitivity was enhanced with HIIT only ( P = 0.003 ) . CONCLUSIONS HIIT seems to benefit appetite regulation in overweight men . The mechanisms for this remain to be eluci date Background Dietary fibers are associated with enhanced satiety . However , the mechanism of different dietary fibers contributing to satiety-related gastrointestinal ( GI ) peptide release , especially in an obese population , is still poorly understood . Polydextrose ( PDX ) , a water-soluble glucose polymer , has demonstrated its ability to reduce energy intake at a subsequent meal , but its mechanism of action requires further research . Also , there is limited evidence on its capacity to regulate subjective feelings of appetite . This study examines the effects of PDX on postpr and ial secretion of satiety-related GI peptides , short chain fatty acids ( SCFAs ) , lactic acid , and subjective appetite ratings in obese participants . Methods 18 non-diabetic , obese participants ( 42.0 y , 33.6 kg/m2 ) consumed a high-fat meal ( 4293 kJ , 36 % from fat ) with or without PDX ( 15 g ) in an acute , multicenter , r and omized , double-blind , placebo-controlled and crossover trial . Postpr and ial plasma concentrations of satiety-related peptides , namely ghrelin , cholecystokinin ( CCK ) , glucagon-like peptide 1 ( GLP-1 ) , and peptide YY ( PYY ) , as well as SCFAs and lactic acid were assessed . GI peptide , SCFA and lactate concentrations were then modeled using a linear mixed-effects model . The subjective feelings of hunger , satisfaction , and desire to eat were evaluated using visual analogue scales ( VAS ) , which were analyzed as incremental areas under the curve ( iAUC ) during the satiation and satiety periods . Results We found that PDX supplementation increased plasma GLP-1 levels more than the placebo treatment ( P = 0.02 ) . In the whole group , GLP-1 concentrations found in participants older than 40 years old were significantly lower ( P = 0.01 ) as compared to those aged 40 years or less . There were no statistically significant differences in postpr and ial ghrelin , CCK , or PYY responses . The lactic acid concentrations were significantly ( P = 0.01 ) decreased in the PDX group , while no significant changes in SCFAs were found . PDX  reduced iAUC for hunger by 40 % ( P = 0.03 ) and marginally increased satisfaction by 22.5 % ( P = 0.08 ) during the post-meal satiety period . Conclusion Polydextrose increased the postpr and ial secretion of the satiety hormone GLP-1 and reduced hunger after a high-fat meal . PDX also reduced the elevated postpr and ial lactic acid levels in plasma . Therefore , PDX may offer an additional means to regulate inter-meal satiety and improve postpr and ial metabolism in obese participants When previously sedentary men and women follow exercise training programs with ad libitum feeding , men lose body fat , but women do not . The purpose of this study was to evaluate whether this observation could be related to sex differences in the way energy-regulating hormones and appetite perception respond to exercise . Eighteen ( 9 men , 9 women ) overweight/obese individuals completed four bouts of exercise with energy added to the baseline diet to maintain energy balance ( BAL ) , and four bouts without energy added to induce energy deficit ( DEF ) . Concentrations of acylated ghrelin , insulin , and leptin , as well as appetite ratings were measured in response to a meal after a no-exercise baseline and both exercise conditions . In men , acylated ghrelin area under the curve ( AUC ) was not different between conditions . In women , acylated ghrelin AUC was higher after DEF ( + 32 % ) and BAL ( + 25 % ) , and the change from baseline was higher than men ( P < 0.05 ) . In men , insulin AUC was reduced ( -17 % ) after DEF ( P < 0.05 ) , but not BAL . In women , insulin AUC was lower ( P < 0.05 ) after DEF ( -28 % ) and BAL ( -15 % ) . Leptin concentrations were not different across conditions in either sex . In men , but not in women , appetite was inhibited after BAL relative to DEF . The results indicate that , in women , exercise altered energy-regulating hormones in a direction expected to stimulate energy intake , regardless of energy status . In men , the response to exercise was abolished when energy balance was maintained . The data are consistent with the paradigm that mechanisms to maintain body fat are more effective in women Chewing reportedly contributes to satiation and satiety signals . Attempts to document and quantify this have led to small and inconsistent effects . The present trial manipulated oral processing effort though required chewing of gums of different hardness and measured appetitive sensations , energy intake , gastric emptying , GI transit time , and concentrations of glucose , insulin , GLP-1 , ghrelin and pancreatic polypeptide . Sixty adults classified by sex and BMI ( 15 each of lean females , obese females , lean males and obese males ) were tested in a r and omized , controlled , cross-over trial with three arms . They chewed nothing , soft gum or hard gum for 15 min while sipping grape juice ( 10 % of individual energy needs ) containing acetaminophen and lactulose on one day each separated by 7 days . Electromyographic recordings and self-reports were obtained during and after chewing to quantify oral processing effort . Blood was sample d through an indwelling catheter and appetite ratings were obtained at baseline and at 0 , 15 , 30 , 45 , 60 , 90 , 120 , 180 and 240 min after chewing initiation . Breath sample s were collected at 10 min intervals for the first 2h and at 30 min intervals for the next 2h . No effects of chewing were observed for appetitive sensations or gut peptide concentrations . Energy intake tended to decline in lean and increase in obese participants so that daily energy intake differed significantly between the two groups when chewing either gum , while no difference was observed on the non-chewing day . Serum glucose and insulin were significantly lower at selected time points 90 - 240 min after chewing compared to baseline and the non-chewing day . These data indicate chewing effort does not affect appetitive sensations or gut peptide secretion , but may exert a small differential effect on acute energy intake in lean and obese individuals and lead to greater post-pr and ial declines of serum glucose and insulin . The efficacy of gum chewing as a substitute for eating for weight management remains uncertain BACKGROUND Aging is associated with a decrease in appetite and a slowing of gastric emptying . The gastrointestinal hormones cholecystokinin ( CCK ) , glucagon-like peptide 1 ( GLP-1 ) , and peptide YY ( PYY ) may mediate these changes . OBJECTIVE We investigated whether aging influenced the secretion of CCK , GLP-1 , and PYY and their effects on appetite and pyloric motility . DESIGN Eight healthy older ( 65 - 80 y ) and 7 younger ( 20 - 34 y ) men received isoenergetic ( 12.1 kJ/min ) intraduodenal infusions of lipid and glucose for 120 min on separate days . Plasma CCK , GLP-1 , and PYY concentrations were measured . RESULTS Plasma CCK concentrations were higher in older than in younger subjects ( P = 0.004 ) as a result of higher baseline values ( 4.7+/-0.2 compared with 3.2+/-0.2 pmol/L ; P < 0.0001 ) and a greater rise during lipid infusion ( increase from baseline : 7.1+/-0.5 compared with 5.3+/-0.6 pmol/L ; P = 0.048 ) . Plasma GLP-1 and PYY concentrations were not significantly different between groups . The decrease in hunger during intraduodenal lipid infusion was inversely related to the increase in CCK , GLP-1 , and PYY in younger but not older subjects . During intraduodenal lipid infusion , the increase in isolated pyloric pressure wave ( IPPW ) frequency was positively related to GLP-1 and PYY and the increase in IPPW amplitude was positively related to CCK in older but not younger subjects , whereas the increase in IPPW amplitude and pyloric tone was negatively related to GLP-1 and PYY in younger subjects . CONCLUSIONS Human aging is associated with increased CCK concentrations , which may contribute to the slowing of gastric emptying , mediated by increased pyloric motility . The role of increased plasma CCK concentrations in mediating the age-related decrease in appetite remains to be established BACKGROUND : Observational studies have shown an inverse association between  dietary calcium intake and body weight , and a causal relation is likely . However , the underlying mechanisms are not understood . OBJECTIVE : We examined whether high and low calcium intakes from mainly low-fat dairy products , in diets high or normal in protein content , have effects on 24-h energy expenditure ( EE ) and substrate oxidation , fecal energy and fat excretion , and concentrations of substrates and hormones involved in energy metabolism and appetite . DESIGN : In all , 10 subjects participated in a r and omized crossover study of three isocaloric 1-week diets with : low calcium and normal protein ( LC/NP : 500 mg calcium , 15 % of energy ( E% ) from protein ) , high calcium and normal protein ( HC/NP : 1800 mg calcium , 15E% protein ) , and high calcium and high protein ( HC/HP : 1800 mg calcium , 23E% protein ) . RESULTS : The calcium intake had no effect on 24-h EE or fat oxidation , but fecal fat excretion increased ∼2.5-fold during the HC/NP diet compared with the LC/NP and the HC/HP diets ( 14.2 vs 6.0 and 5.9 g/day ; P<0.05 ) . The HC/NP diet also increased fecal energy excretion as compared with the LC/NP and the HC/HP diets ( 1045 vs 684 and 668 kJ/day ; P<0.05 ) . There were no effects on blood cholesterol , free fatty acids , triacylglycerol , insulin , leptin , or thyroid hormones . CONCLUSIONS : A short-term increase in dietary calcium intake , together with a normal protein intake , increased fecal fat and energy excretion by ∼350 kJ/day . This observation may contribute to explain why a high-calcium diet produces weight loss , and it suggests that an interaction with dietary protein level may be important We assessed evidence for changes in efficacy of  food-based interventions  aim ed at reducing  appetite or energy intake ( EI )  , and whether this could be used to provide guidance on trial design . A systematic search identified r and omized controlled trials testing sustained efficacy of diets , foods , supplements or food ingredients on appetite and /or EI . Trials had to include sufficient exposure duration ( ≥3 days ) with appetite and /or EI measured after both acute and repeated exposures . Twenty-six trials met the inclusion criteria and reported data allowing for assessment of the acute and chronic effects of interventions . Most ( 21/26 ) measured appetite outcomes and over half ( 14/26 ) had objective measures of EI . A significant acute effect of the intervention was retained in 10 of 12 trials for appetite outcomes , and six of nine studies for EI . Initial effects were most likely retained where these were more robust and studies adequately powered . Where the initial , acute effect was not statistically significant , a significant effect was later observed in only two of nine studies for appetite and none of five studies for EI . Maintenance of intervention effects on appetite or EI needs to be confirmed but seems likely where acute effects are robust and replicable in adequately powered studies Dietary regulation of appetite may contribute to the prevention and management of excess body weight . The present study examined the effect of consumption of individual dairy products as snacks on appetite and subsequent ad libitum lunch energy intake . In a r and omised cross-over trial , forty overweight men ( age 32 ( sd 9 ) years ; BMI 27 ( sd 2 ) kg/m2 ) attended four sessions 1 week apart and received three isoenergetic ( 841 kJ ) and isovolumetric ( 410 ml ) servings of dairy snacks or water ( control ) 120 min after breakfast .  Appetite profile was determined throughout the morning and ad libitum energy intake was assessed 90 min after the intake of snacks . Concentrations of amino acids , glucose , insulin , ghrelin and peptide tyrosine tyrosine were measured at baseline ( 0 min ) and 80 min after the intake of snacks . Although the results showed that yogurt had the greatest suppressive effect on appetite , this could be confounded by the poor sensory ratings of yogurt . Hunger rating was 8 , 10 and 24 % ( P < 0·001 ) lower after the intake of yogurt than cheese , milk and water , respectively . Energy intake was 11 , 9 and 12 % ( P < 0·02 ) lower after the intake of yogurt , cheese and milk , respectively , compared with water ( 4312 ( se 226 ) kJ ) . Although there was no difference in the postpr and ial responses of hormones , alanine and isoleucine concentrations were higher after the intake of yogurt than cheese and milk ( P < 0·05 ) . In conclusion , all dairy snacks reduced appetite and lunch intake compared with water . Yogurt had the greatest effect on suppressing subjective appetite ratings , but did not affect subsequent food intake compared with milk or cheese In rats , oligofructose has been shown to stimulate satiety hormone secretion , reduce energy intake and promote weight loss . The present study aim ed to examine the effect of oligofructose supplementation on appetite profiles , satiety hormone concentrations and energy intake in human subjects . A total of thirty-one healthy subjects ( ten men and twenty-one women ) aged 28 ( SEM 3 ) years with a BMI of 24·8 ( SEM 0·3 ) kg/m(2 ) were included in a r and omised double-blind , cross-over study . The subjects received 10 g oligofructose , 16 g oligofructose or 16 g placebo ( maltodextrin ) daily for 13 d , with a 2-week washout period between treatments . Appetite profile , active glucagon-like peptide 1 ( GLP-1 ) and peptide YY3 - 36 ( PYY ) concentrations and energy intake were assessed on days 0 and 13 of the treatment period . Time × treatment interaction revealed a trend of reduction in energy intake over days 0 - 13 by oligofructose  ( P = 0·068 ) . Energy intake was significantly reduced ( 11 % ) over time on day 13 compared with day 0 with 16 g/d oligofructose ( 2801 ( SEM 301 ) v. 3217 ( SEM 320 ) kJ , P < 0·05 ) . Moreover , energy intake was significantly lower with 16 g/d oligofructose compared with 10 g/d oligofructose on day 13 ( 2801 ( SEM 301 ) v. 3177 ( SEM 276 ) kJ , P < 0·05 ) . Area under the curve ( AUC ) for GLP-1 on day 13 was significantly higher with 16 g/d oligofructose compared with 10 g/d oligofructose ( 45 ( SEM 4 ) v. 41 ( SEM 3 ) pmol/l × h , P < 0·05 ) . In the morning until lunch , AUC(0 - 230 min ) for PYY on day 13 was significantly higher with 16 g/d oligofructose compared with 10 g/d oligofructose and placebo ( 409 ( SEM 35 ) v. 222 ( SEM 19 ) and 211 ( SEM 20 ) pg/ml × h , P < 0·01 ) . In conclusion , 16 g/d and not 10 g/d oligofructose may be an effective dose to reduce energy intake , possibly supported by higher GLP-1 and PYY concentrations
Higher circulating concentrations of insulin , leptin , cholecystokinin and peptide-YY accord with reduced appetite and energy intakes in healthy older adults .
Interventions to reduce circulating levels of these hormones may be beneficial for combatting the anorexia of ageing
Ageing is associated with reduced appetite and energy intakes .
However , the mechanisms underlying this phenomenon are not fully understood .
This systematic review and meta- analysis quantified differences in circulating concentrations of appetite-related hormones between healthy older and younger adults .