***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Background There is limited , and inconsistent , data on the prospect i ve association between physical activity and surrogate markers of adiposity in older adults . We aim to determine the prospect i ve association of leisure time physical activity ( LTPA ) with body mass index ( BMI ) , waist circumference ( WC ) and the incidence of obesity . Methods This prospect i ve analysis included 7144 individuals with a mean age of 67 ± 6.2 years , from the PREvención con DIeta MEDiterránea ( PREDIMED ) study .  BMI and WC were measured and LTPA was recorded using the Minnesota Leisure Time Physical Activity Question naire . Exposure and outcome variables were calculated as cumulative average of repeated measurements . Results Total LTPA was inversely associated ( P < 0.001 ) with BMI and WC . The difference in BMI and WC between extreme quintiles of LTPA ( Q1-Q5 ) was 2.1 kg/m2 ( 95 % confidence interval ( CI ) 1.68 ; 2.49 , P < 0.001 ) and 4.8 cm ( CI 2.28 ; 7.25 , P < 0.001 ) , respectively . Low-intensity LTPA was inversely associated with BMI but not with WC , while moderate/vigorous LTPA showed an inverse relationship with BMI and WC . The hazard of general and abdominal obesity incidence decreased across quintiles of total and moderate/vigorous LTPA ( P < 0.001 for both ) , whereas low-intensity LTPA was inversely associated with the incidence of general obesity ( P < 0.001 ) . Conclusion LTPA was inversely associated with BMI , WC and incidence of general and abdominal obesity . The finding that low-intensity LTPA was inversely related to BMI and the incidence of obesity is of particular importance because this level of physical activity could be a feasible option for many older adults 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 Overweight/obesity is a chronic disease that carries an increased risk of hypertension , diabetes mellitus , and premature death . Several epidemiological studies have demonstrated a clear relationship between salt intake and obesity , but the pathophysiologic mechanisms remain unknown . We hypothesized that ghrelin , which regulates appetite , food intake , and fat deposition , becomes elevated when one consumes a high-salt diet , contributing to the progression of obesity . We , therefore , investigated fasting ghrelin concentrations during a high-salt diet . Thirty-eight non-obese and normotensive subjects ( aged 25 to 50 years ) were selected from a rural community in Northern China . They were sequentially maintained on a normal diet for three days at baseline , a low-salt diet for seven days ( 3 g/day , NaCl ) , then a high-salt diet for seven days ( 18 g/day ) . The concentration of plasma ghrelin was measured using an immunoenzyme method ( ELISA ) . High-salt intake significantly increased fasting ghrelin levels , which were higher during the high-salt diet ( 320.7 ± 30.6 pg/mL ) than during the low-salt diet ( 172.9 ± 8.9 pg/mL ) . The comparison of ghrelin levels between the different salt diets was statistically-significantly different ( p < 0.01 ) . A positive correlation between 24-h urinary sodium excretion and fasting ghrelin levels was demonstrated . Our data indicate that a high-salt diet elevates fasting ghrelin in healthy human subjects , which may be a novel underlying mechanism of obesity Background / Aims Bitter taste receptors are expressed throughout the digestive tract . Data on animals have suggested these receptors are involved in the gut hormone release , but no data are available in humans . Our aim is to assess whether bitter agonists influence food intake and gut hormone release in healthy subjects . Methods Twenty healthy volunteers were enrolled in a double-blind cross-over study . On 2 different days , each subject r and omly received an acid-resistant capsule containing either placebo or 18 mg of hydrochloride ( HCl ) quinine . After 60 minutes , all subjects were allowed to eat an ad libitum meal until satiated . Plasma sample s were obtained during the experiment in order to evaluate cholecystokinin ( CCK ) and ghrelin levels . Each subject was screened to determine phenylthiocarbamide ( PTC ) tasting status . Results Calorie intake was significantly lower when subjects received HCl quinine than placebo ( 514 ± 248 vs 596 ± 286 kcal ; P = 0.007 ) . Significantly higher CCK ΔT90 vs T0 and ΔT90 vs T60 were found when subjects received HCl quinine than placebo ( 0.70 ± 0.69 vs 0.10 ± 0.86 ng/mL , P = 0.026 ; 0.92 ± 0.75 vs 0.50 ± 0.55 ng/mL , P = 0.033 , respectively ) . PTC tasters ingested a significantly lower amount of calories when they received HCl quinine compared to placebo ( 526 ± 275 vs 659 ± 320 kcal ; P = 0.005 ) , whereas no significant differences were found for PTC non-tasters ( 499 ± 227 vs 519 ± 231 kcal ; P = 0.525 ) . Conclusions This study showed that intra-duodenal release of a bitter compound is able to significantly affect calorie intake and CCK release after a st and ardized meal . Our results suggest that bitter taste receptor signaling may have a crucial role in the control of food intake OBJECTIVE Patients who have undergone Roux-en-Y gastric bypass ( RYGB ) for clinical ly severe obesity often report an aversion to sweet foods and meat . This study was design ed to determine whether changes in taste acuity occur after RYGB . DESIGN This prospect i ve , repeated measures trial evaluated acuity for sweet ( sucrose ) and bitter ( urea ) tastes , zinc status , and reported changes in taste perceptions in patients undergoing RYGB for weight reduction . SUBJECTS Taste acuity and serum zinc level were measured in 14 subjects , 6 men and 8 women ( mean preoperative body mass index [ calculated as kg/m2 ] = 60.8 + /- 11.8 and mean age = 38.4 + /- 6 years ) , before surgery and 6 and 12 weeks after surgery . Inquiries regarding taste preferences were made at each postoperative visit with specific reference to sweets and meat . Serum zinc level was measured at the same visit . A noncontrolled comparison group of 4 subjects who were consuming a very-low-calorie diet  also underwent taste acuity testing at similar intervals . MAIN OUTCOME MEASURES The main outcome measures were recognition taste thresholds , serum zinc levels , and taste preference changes . STATISTICAL ANALYSIS Analysis of variance with repeated measures over time , Pearson correlation coefficients , and post hoc analysis of variance were used to analyze data . RESULTS Mean recognition thresholds for sucrose were 0.047 + /- 0.03 mol/L preoperatively and fell significantly to 0.024 + /- 0.01 and 0.019 + /- 0.01 mol/L at 6 and 12 weeks postoperatively , respectively . Overall , there were no significant differences in taste thresholds for urea over time ; a significant difference was noted , however , in the pattern of change for urea between patients who reported an aversion to meats and those who did not . Zinc concentrations did not change during the study . APPLICATION/ CONCLUSIONS At 6 weeks postoperatively , all patients reported that foods tasted sweeter , and they modified food selection accordingly . Six patients reported an aversion to meats associated with increased nausea and vomiting . Acuity for sweet and bitter tastes may need to be considered when planning dietary modifications for patients undergoing RYGB INTRODUCTION Factors leading to weight loss and weight stabilization after  bariatric surgery are not fully understood . Our aim was to evaluate , in Sprague-Dawley rats , the histological and gut hormonal changes after Larrad-biliopancreatic diversion ( Larrad-BPD ) .  MATERIAL S AND METHODS Rats r and omly underwent the following protocol s : Larrad-BPD ( n=4 ) versus pair fed ( PF ) ( n=4 ) .  Weight and food intake were measured every day . By immunohistochemistry ghrelin was examined in the stomach , while cholecystokinin ( CCK ) , glucagon-like-peptide-1 ( GLP-1 ) , peptide YY ( PYY ) and serotonin ( 5-HT ) expression were analyzed in alimentary limb and ileum following or not the Larrad-BPD . RESULTS Larrad-BPD rats exhibited significant ( P<0.05 ) weight loss compared to PF rats . Villi enlongation was observed in Larrad-BPD rats . In residual stomach , ghrelin was diminished . In the alimentary limb , ghrelin and CCK positive cells were detected more than in the ileum of PF rats . GLP-1 expression was decreased and PYY expression was absent after Larrad-BPD compared with PF rats . DISCUSSION Larrad-BPD is followed by histological changes and a pleiotropic gut endocrine response aim ed to compensate the reduction of intestinal area exposed to food . Until now , the hormones responsible for the intestinal hypertrophy have not been defined BACKGROUND AND AIM Jejunoileal bypass surgery for obesity increases the risk of gallstone formation , and , contrary to expectations , the incidence is greater in patients with a long as compared to a short ileum left in continuity . Impaired gallbladder motility due to reduced cholecystokinin ( CCK ) stimulation could be an explanation . The aim of this study was to investigate the CCK levels in such patients . SETTING The r and omized trial of bypass surgery named The Danish Obesity Project . DESIGN AND METHODS We compared plasma levels of CCK in obese patients at three , nine or 15 months after jejunoileal bypass surgery with either a 1:3 jejunoileal ratio ( n = 14 ) or a 3:1 ratio ( n = 15 ) , and in unoperated obese patients ( n = 7 ) .  Plasma CCK levels were determined during fasting and during 150 min following ingestion of a liquid test meal . RESULTS There were no significant changes over time following surgery . Basal CCK levels were significantly increased after surgery , and significantly higher in those with a 3:1 than in those with a 1:3 jejunoileal ratio . The postpr and ial AUC ( mean + /- SEM ) was 935 + /- 71 pM x min in the 3:1 ratio group and 891 + /- 100 pM x min in the 1:3 ratio group . This difference was not significant , but both bypass groups were significantly higher than the unoperated group ( 515 + /- 79 pM x min ) . The integrated increase in plasma CCK above basal level showed a similar pattern , but the difference between the unoperated and the bypass groups was insignificant . 
    Output:
    
Results Our study showed that bariatric surgery is associated with significant change in sensitivity to all four taste domains especially salt taste , sweetness , and sourness .
LSG patients showed an increased sensitivity to all four taste domains .
However , RYGB patients had a variable alteration pattern of taste perception but more commonly a decreased sensitivity to sweetness and an increased sensitivity to salt taste and sourness .
Additionally , AGB patients had a decreased sensitivity to sweetness , salt taste , and sourness .
Conclusion Bariatric surgery is associated with taste change in a way which results in less preference for high-calorie food and possibly reduced calorie intake .
This may explain one of the mechanisms by which bariatric surgery produces weight loss .