Ghrelin Responses Research Articles

Pleurotus eryngii improves postprandial glycaemia, hunger and fullness perception, and enhances ghrelin suppression in people with metabolically unhealthy obesity

The aim of this study was to examine potential postprandial benefits of Pleurotus eryngii in nineteen volunteers with metabolically unhealthy obesity. An acute, randomized, crossover-designed trial comparing a meal with Pleurotus eryngii and a control meal was performed. The two meals matched in macronutrient and caloric content. Participants consumed both meals in random order after an overnight fast. Blood samples were drawn before and 30, 60, 90, 120, 150 and 180 min after meal consumption (in total 266 samples) to determine glucose, insulin, ghrelin, peptide YY, glucagon-like peptide-1 and glicentin. Visual analog scales measuring the subjective perception of hunger and fullness were completed at the same time points. The test meal resulted in lower glucose incremental area under the curve (iAUC). Additionally, the iAUC of the ghrelin response over time was substantially lower after the test meal (p = 0.033). Lower desire to eat and higher fullness was reflected by significantly lower hunger iAUC (p = 0.046) and higher fullness iAUC (p = 0.042) after the test meal. No differences in insulin, PYY, GLP-1 and glicentin were observed. Pleurotus eryngii can ameliorate postprandial glycaemia, appetite and regulate ghrelin levels at the postprandial state. This effect is attributed to the bioactive polysaccharides that inhibit the activity of enzymes catalysing carbohydrate hydrolysis, cause a delayed gastric emptying and glucose absorption.

Effects of 12-week, non-energy-restricted dietary intervention with conventional yogurt οn appetite hormone responses of type 2 diabetic patients.

Hunger‐reducing effects and beneficial changes in gastrointestinal hormones have been reported, in overweight/obese individuals consuming dairy while yogurt takes pride of place due to its unique structure and composition. Although the contribution of yogurt to metabolic regulation has received growing attention, the research studies which examine its role on appetite are limited, especially regarding type 2 diabetes mellitus (T2DM) patients. The aim of the present study was to investigate the effects of non‐fat, conventional yogurt consumption on appetite hormone responses of T2DM patients following a non‐energy‐restricted diet. Overweight subjects participated in a 12‐week dietary intervention including 2 meals/day (2 × 200 g) of yogurt. At the beginning and the end of the intervention, a mixed meal tolerance test assessing the postprandial response of glucose, insulin, ghrelin, glucagon‐like peptide‐1 (GLP‐1), and peptide‐YY (PYY) was performed. Subjective appetite ratings were also evaluated. Area under the curve for glucose, insulin, ghrelin, GLP‐1, and PYY responses did not differ after the 12‐week intervention with yogurt (p > .05) as well as for subjective appetite ratings (p > .05). No significant differences were indicated at specific time points in any of the examined parameters. Regular consumption of non‐fat, conventional yogurt for 12‐week duration does not affect appetite hormone responses in overweight patients with T2DM following a non‐energy‐restricted diet.

Salivary ghrelin response to drinks varying in protein content and quantity and association with energy intake and appetite.

Salivary hormone analysis is a non-invasive alternative to blood-borne hormone analysis. The orexigenic hormone ghrelin has been detected in human saliva, though the relationship between salivary and blood-borne ghrelin and salivary ghrelin's association with energy intake (EI) and appetite remains unclear. The primary aim of this study was to compare salivary and plasma ghrelin responses to dairy breakfast drinks varying in protein content and quantity, and to determine the relationship between salivary ghrelin and EI and appetite. Participants (n = 25) consumed four test drinks, varying in protein content and quantity, on four separate days in a double-blind randomized controlled study. Salivary and plasma total ghrelin were measured at 0, 30, 60 and 120 min and appetite perceptions at 0, 30, 60, 90 and 120 min. A buffet-style test meal was presented at 120 min to measure ad libitum EI. There was no correlation between the sample means for fasted salivary and plasma ghrelin (r = 0.099, p = 0.637). Furthermore, there was no within-participant association between fasted salivary and plasma ghrelin (r = -0.041, p = 0.725). Mean bias between fasted salivary and plasma ghrelin was -448 pg/ml (95% confidence intervals (CI) = -623 – -273 pg/ml) and upper and lower limits of agreement (LOA) were 427 pg/ml and -1324 pg/ml, respectively. Variation in postprandial levels of salivary and plasma ghrelin within-participants were not associated (r = -0.004, p = 0.943). There was no significant association between EI and salivary (r = 0.003, p = 0.979) or plasma (r = -0.080, p = 0.492) ghrelin. Salivary ghrelin was not significantly correlated with composite appetite score (r = 0.023; p = 0.654), though plasma ghrelin was (r = 0.225, p < 0.001). Mean bias between postprandial salivary and plasma ghrelin was -210 pg/ml (95% CI = -380 – -40 pg/ml) and upper and lower LOA were 641 pg/ml and -1061 pg/ml, respectively. These findings suggest that salivary and plasma ghrelin responses to drinks varying in protein content and quantity are unrelated and that salivary ghrelin is not associated with EI or appetite perceptions in healthy non-obese adults. This trial was registered at www.clinicaltrial.gov (NCT01597024).

Are the Changes in Gastrointestinal Hormone Secretion Necessary for the Success of Bariatric Surgery? A Critical Review of the Literature.

Ghrelin, glucagon-like peptide-1 (GLP-1), and peptide YY (PYY) are involved in energy balance regulation and glucose homeostasis. Obesity is characterized by lower fasting levels and blunted postprandial responses of ghrelin, GLP-1, and possibly PYY. Both Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) have been shown to increase postprandial GLP-1 and PYY levels. Human studies have shown that enhanced postprandial GLP-1 and PYY release are associated with favorable weight loss outcomes after RYGB. However, studies in knockout mice have shown that GI hormones are not required for the primary metabolic effects of bariatric surgery. Here, we summarize the complex interaction between obesity, bariatric surgery, and GI hormones in order to determine the exact role of GI hormones in the success of bariatric surgery.

Correlation of body mass index to Ghrelin and IGF-1 among children with short stature

ObjectiveTo assess the BMI among children with Growth Hormone Deficiency (GHD) and Idiopathic Short Stature (ISS) and its correlation to ghrelin, Growth Hormone (GH), and Insulin-like Growth Factor-1 (IGF-1) levels. MethodsA cross-sectional descriptive study in which 42 patients attending the Pediatric endocrine clinic were enrolled, allocated into two groups: group I: GHD children; group II: ISS children. Ghrelin, IGF-1 and GH in both groups were measured. ResultsGhrelin was significantly higher among GHD group (p < 0.001). Overall, there was a strong negative correlation between IGF-1 and ghrelin (r = -0.977, p-value = < 0.001) while a moderate positive correlation between ghrelin and BMI (r = 0.419, p-value = 0.006). There was a weak positive non-significant correlation between IGF-1 and BMI (r = 0.276, p-value = 0.077). In GHD group, there was a weak positive non-significant correlation between ghrelin and GHmax measurement (r = 0.052, p-value = 0.824), while a weak negative non-significant correlation between both variables in ISS group (r = -0.243, p-value = 0.288). In GHD group, there was a moderate positive correlation between ghrelin and BMI (r = 0.500, p-value = 0.021), but weak negative non-significant correlation between both variables in ISS group (r = -0.255, p-value = 0.265). ConclusionThere was a negative feedback loop between ghrelin and IGF-1, whereas a positive feedback between ghrelin and BMI. BMI was more affected in the ISS group but was non-significantly correlated with ghrelin. There was no significant compensatory response of ghrelin suggesting its contribution to the pathogenesis of ISS.

Acute Effects of Sleeve Gastrectomy on Glucose Variability, Glucose Metabolism, and Ghrelin Response.

This study aims to examine the changes of glucose metabolism, glucose variability (GV), and ghrelin secretion within 1 week following SG in Chinese patients with obesity. Forty-nine patients with obesity (15 with type 2 diabetes) were enrolled to undergo SG. Within 1 week before and after surgery, liquid meal tests were performed in all subjects, and continuous glucose monitoring (CGM) was performed in diabetic patients. Blood samples were collected at 0, 15, 30, 45, 60, 120, and 180 min for glucose, C-peptide, insulin, and ghrelin analysis in liquid meal test. Mean amplitude of glucose excursions (MAGE), standard deviations (SD), and percent time-in-range (%TIR) determined by CGM were analyzed. Both in diabetic and non-diabetic groups, significant decrease was observed in glucose, insulin, C-peptide, and ghrelin. Homeostasis model assessment-insulin resistance and liver fat content was decreased. In diabetic group, MAGE and SD were decreased significantly, and the percent time-in-range was higher. The decrease in blood glucose was positively correlated with the decrease in ghrelin concentration in non-diabetic group. Within 1 week after SG, both glucose metabolism and glucose variability were improved significantly. Suppression of ghrelin secretion postoperatively might be a driver of this early improved glycemia homeostasis.

Oxidative stress and inflammatory response of ghrelin on myocardial and aortic tissues in insulin-resistant rats.

This study was designed to clarify the effects of ghrelin on myocardial and aortic tissues in insulin-resistant rats. Sprague-Dawley rats were divided into the following groups: control (Group 1), insulin resistance (IR, Group 2), ghrelin (Group 3) and IR+Ghrelin (Group 4) groups. Levels of HOMA-IR, fibronectin, hydroxyproline, collagen-1, collagen-3, matrix metalloproteinase-3, and matrix metalloproteinase-9, and tissue inhibitor of metalloproteinase-1, and oxidative stress parameters as protein carbonyl (PCO), lipid hydroperoxides (LHPs), malondialdehyde, total thiol were determined in myocardial tissue. Expressions of IL-6, NF-κB and TNF-α mRNAs were detected by RT-qPCR. Aorta tissue was stained Masson trichrome. The HOMA-IR level decreased in the IR+Ghrelin group compared with the IR group (P < 0.001). The PCO and LHP concentrations were higher in the IR group compared with control rats (P < 0.05). The PCO level was reduced by ghrelin in the IR+Ghrelin group compared with the IR group (P < 0.001). Ghrelin treatment reduced the mRNA expression levels of IL-6, NF-κB and TNF-α in the IR+Ghrelin group compared with the IR group (P < 0.001). There was no difference among the groups in the histology of aortic tissue. Ghrelin, a regulator of appetite and energy homeostasis, may be effective in regulating oxidative stress and the inflammatory response when impaired by IR. Therefore, ghrelin may reduce the risks of myocardial dysfunction in IR.

Ablation of Nampt in AgRP neurons leads to neurodegeneration and impairs fasting- and ghrelin-mediated food intake.

Agouti-related protein (AgRP) neurons in the arcuate nucleus of the hypothalamus regulates food intake and whole-body metabolism. NAD+ regulates multiple cellular processes controlling energy metabolism. Yet, its role in hypothalamic AgRP neurons to control food intake is poorly understood. Here, we aimed to assess whether genetic deletion of nicotinamide phosphoribosyltransferase (Nampt), a rate-limiting enzyme in NAD+ production, affects AgRP neuronal function to impact whole-body metabolism and food intake. Metabolic parameters during fed and fasted states, and upon systemic ghrelin and leptin administration were studied in AgRP-specific Nampt knockout (ARNKO) mice. We monitored neuropeptide expression levels and density of AgRP neurons in ARNKO mice from embryonic to adult age. NPY cells were used to determine effects of NAMPT inhibition on neuronal viability, energy status, and oxidative stress in vitro. In these cells, NAD+ depletion reduced ATP levels, increased oxidative stress, and promoted cell death. Agrp expression in the hypothalamus of ARNKO mice gradually decreased after weaning due to progressive AgRP neuron degeneration. Adult ARNKO mice had normal glucose and insulin tolerance, but exhibited an elevated respiratory exchange ratio (RER) when fasted. Remarkably, fasting-induced food intake was unaffected in ARNKO mice when evaluated in metabolic cages, but fasting- and ghrelin-induced feeding and body weight gain decreased in ARNKO mice when evaluated outside metabolic cages. Collectively, deletion of Nampt in AgRP neurons causes progressive neurodegeneration and impairs fasting and ghrelin responses in a context-dependent manner. Our data highlight an essential role of Nampt in AgRP neuron function and viability.

The Impact of Chronic Stress and Eating Concern on Acylated Ghrelin Following Acute Psychological Stress in Healthy Men

Stress, mood, and eating behavior play an important role in appetite and weight regulation. In particular, ghrelin, as the only known orexigenic hormone, has been suggested to be an influential mediator in food intake responses to stress. The exact role of ghrelin in the hypothalamic–pituitary–adrenal axis is still unknown and further challenged by the psychological aspects of stress and eating behavior. This study aimed to assess the effect of chronic stress and subjective concern about eating on acute stress-induced changes in acylated ghrelin. In a 2-day study, sixteen healthy male participants were confronted with a stressful situation as well as a control situation. Additional measurements of heart rate, subjective hunger ratings, and subjective mood ratings were made to assess successful acute stress induction. The linear mixed model approach revealed a significant effect of acute stress on acylated ghrelin for a study-day*chronic-stress interaction (p &lt; 0.001). Concern about eating did not affect acylated ghrelin levels after acute stress exposure. The significant interaction showed that lower chronic stress exposure was associated with a stronger acylated ghrelin response after acute stress exposure versus control condition. At the same time, participants with higher chronic stress exposure showed a blunted acylated ghrelin response after acute stress exposure compared to the control situation. Our findings indicate that chronic stress exposure can influence acylated ghrelin response after acute stress encounters, possibly affecting subsequent food intake and explaining the often diverse outcome in measurements of acute stress responses.

Weight loss with or without intragastric balloon causes divergent effects on ghrelin cell expression.

ObjectiveThe mechanism of action of intragastric balloons in the treatment of obesity is not fully understood. One of the hypotheses is that balloons might have an effect on the fundus, the area of ghrelin production.MethodsParticipants were randomized to a 13‐week period of sham or balloon treatment followed by a 13‐week period of balloon therapy in everyone. Blood samples for ghrelin levels were taken in the fasting state and after a breakfast at the start, after 13 and 26 weeks. Biopsies for ghrelin cell immunohistochemistry were taken from the fundus at endoscopy.ResultsSeven participants entered the balloon–balloon (BB) group and 11 the sham–balloon (SB) group. Despite a considerable weight loss, a median −17.9 kg (interquartile ranges −23.8 to −0.5) in the BB group and −18.3 kg (−22.7 to −14.7) in the SB group, fasting ghrelin and meal‐induced ghrelin response did not change. In the SB group, the number of ghrelin cells increased significantly (p 0.001) from 110.6 (83.6–118.9) to 160.2 (128.5–223.0) while on sham treatment and returned to initial levels, 116.3 (91.7–146.9) (p 0.001), when they received their first balloon. No significant changes in ghrelin cell numbers were observed in the BB group.ConclusionIn participants without a balloon, weight loss induced an increase in ghrelin cell numbers in the fundus, which was annulled by the subsequent placement of a balloon. The effect of a balloon might be explained by effects on ghrelin cell numbers or ghrelin cell activity.

Altered acylated ghrelin response to food intake in congenital generalized lipodystrophy.

BackgroundPatients with congenital generalized lipodystrophy (CGL) have very low levels of leptin and are described as having a voracious appetite. However, a direct comparison between CGL and eutrophic individuals is lacking, regarding both appetite parameters and acylated ghrelin, the hormone form that is active in acute food intake stimulation. The objective of the present study was to address whether and in what extent the subjective appetite parameters and acylated ghrelin response to a meal are affected in CGL individuals, in comparison to eutrophic individuals. Additionally, an obese group was included in the study, to allow the comparison between a leptin-resistant and a leptin-deficient condition on these aspects.MethodsEutrophic controls (EUT, n = 10), obese subjects (OB, n = 10) and CGL (n = 11) were fasted overnight and then received an ad libitum meal. Blood was collected and the visual analogue scale was applied before and 90 minutes after the meal. An additional blood sample was collected at 60 minutes for ghrelin determination.ResultsThe CGL patients showed low fasting levels of leptin and adiponectin, dyslipidemia, and insulin resistance. The caloric intake was similar among the 3 groups. However, both CGL (p = 0.02) and OB (p = 0.04) had shorter satiation times than EUT. The CGL patients also had lower satiety time (p = 0.01) and their sensation of hunger was less attenuated by the meal (p = 0.03). Fasting acylated ghrelin levels were lower in CGL than in EUT (p = 0.003). After the meal, the levels tended to decrease in EUT but not in CGL and OB individuals.ConclusionThe data indicate that, although not hyperphagic, the CGL patients present appetite disturbances in relation to eutrophic individuals. Their low fasting levels of acylated ghrelin and the absence of the physiological drop after meal intake suggest a role of these disturbances in hunger attenuation and satiety but not in acute satiation.

Influence of glycaemic index on subjective appetite responses in healthy adults

The glycaemic index (GI) of carbohydrate foods is a useful tool for predicting postprandial glucose and insulin responses(1). Results from human studies suggest an inverse relationship between GI of ingested food and postprandial appetite responses(2). However, evidence on the effects of GI on subjective and objective satiety responses is inconclusive(3). Therefore, the aim of this study was to assess the impact of GI on postprandial appetite response in humans. We conducted a randomised controlled crossover trial on 13 adults presenting with normoglycaemia, normal BMI and mean age of 28.7 ± 6.6 years. Participants were randomly allocated to consume a high GI meal (HGI) consisting of mashed potatoes, and low GI (LGI) meal of canned whole chickpeas, each providing 50 g total available carbohydrates, after an overnight fast. Postprandial subjective satiety and appetite responses were captured using visual analogue scale (VAS) in 3 domains: hunger, fullness, and prospective food intake. Plasma ghrelin values were also measured by immunoassay (intra-assay variations < 15%), in venous blood samples collected over 3 hours following breakfast intake. Postprandial total area under the curves (AUCs) were calculated by the trapezoidal method, and data were analysed using t-test with statistical significance set at p < 0.05. Data are presented as mean ± SD. There were great variations observed in individual responses after intake of both interventions in all outcomes illustrated above. Postprandial hunger responses were significantly lower after ingestion of LGI meal (91.2 ± 37.1 mm × h) in comparison to HGI meal (113.5 ± 26 mm × h) (p = 0.035); and postprandial fullness responses were significantly higher as demonstrated by AUC values over the 3 hour period following breakfast intake (107.3 ± 37.1 mm × h) and (80.2 ± 24.7 mm × h) (p = 0.012) respectively. However, there was no significant difference in prospective food intake following different GI meals (104.6 ± 41.9 mm × h) and (126.2 ± 26.3 mm × h), respectively. In addition, there were no differences observed in postprandial ghrelin response (p > 0.05). The results suggest that a low meal GI positively affects postprandial satiety response. However, the impact on appetite hormone ghrelin is unclear possibly due to high individual variances in hormonal responses.

47 Quantitative evaluation of hunger in pregnant sows: metabolic and hormonal responses to feeding frequency under limit-fed regime

Abstract The objectives of the study were to determine the pattern of glucose, insulin, active ghrelin, and total PYY responses and indirectly quantify perceived hunger in pregnant sows under-limit fed conditions. Eighteen sows [(Landrace × Yorkshire); BW 211.86 ± 1.29 kg; parity 3.80 ± 0.16; backfat 13.50 ± 0.25 mm)] were sampled from 180 sows. Sows were blocked by parity and BW and randomly assigned to 1 of 3 treatments in a RCBD. Treatments included sows fed once at [0730 h (Control, T1), twice [half ration at 0730 and 1530 h (T2)], or thrice [one-third portion at 0730, 1130, and 1530 h (T3)]. The daily feed quantity was kept at 1.25× maintenance energy intake (100 × (BW)0.75) kcal ME/d. Sows received corn-soybean meal-based diet which provided 6935 kcal ME/d and SID Lys:ME of 1.71 g/Mcal from d 30 to 60 of gestation. Hunger was quantified using total area under the curve (AUC) of the hormonal responses. Data analysis was done using PROC MIXED and GLIMMIX procedure of SAS. Sow was the experimental unit. Adjustment for multiple comparisons was by Tukey’s method. The control sows had greater 23-h mean glucose concentration than sows fed 3× daily (P = 0.002). Active ghrelin concentration for sows fed 3× daily tended to be lower (P = 0.063) compared with control sows but reduced (P = 0.018) relative to sows fed 2× daily. In conclusion, sows fed 3× daily had 9.0% reduction in 23-h glucose total AUC, 42.5% greater 23-h insulin total AUC, 27.4% reduction in active ghrelin total AUC, and 14.2% greater PYY total AUC compared with pregnant sows fed 1× daily. It is suggested that hunger in pregnant sows occurs at active ghrelin/total PYY ratio of 5.06 ± 0.20 and at a mean plasma glucose concentration of 70.37 ± 1.39 mg/dL and below.

Secondary analysis of gut hormone data from children with and without in utero exposure to gestational diabetes: Differences in the associations among ghrelin, GLP-1, and insulin secretion.

Intrauterine exposure to gestational diabetes mellitus (GDM) increases risk for type 2 diabetes (T2D). Ghrelin and GLP-1 have opposite functions in nutritional homeostasis and are associated with insulin secretion, but it is not known if individuals exposed to GDM exhibit dysregulation in these associations. Test the hypothesis that children exposed to GDM in utero will exhibit dysregulation among ghrelin, GLP-1, and C-peptide (reflecting insulin secretion). Data from N = 43 children aged 5 to 10 years were included in this secondary analysis of ghrelin, GLP-1, and C-peptide response to a liquid meal test. Repeated measures mixed model analyses were used to measure associations among hormones. The association of ghrelin and GLP-1 was moderated by GDM group (P < .01), such that ghrelin was inversely associated with GLP-1 in children without GDM exposure, but not for those exposed to GDM. GLP-1 was positively associated with C-peptide in both groups, but the association was stronger in those exposed to GDM (estimate = 1.06 vs 1.01). Differences in the associations among ghrelin, GLP-1, and C-peptide displayed here suggest novel lines of research about whether the regulation of gut hormones and insulin secretion contribute to obesity and risk for T2D in children exposed to GDM.

Comparing Hunger and Thirst Perception and Related Biomarker Response After Carbonated Beverage Consumption

Abstract Objectives To determine if there were relationships between biomarkers of thirst, hunger, perceived thirst and perceived hunger in relation to time and carbonated beverage consumption. Methods Participants (males n = 14, females n = 15) aged 23–65, had a BMI &amp;lt; 30 kg/m2, and no reported chronic disease. Participants completed six data collections, arriving four hours fasted and consuming one of six randomized beverages (water, carbonated-no flavor [CNF], carbonated lime flavor [CL], degassed lime flavor [DL], carbonated lime flavor with aspartame [CLS], and degassed lime flavor with aspartame [DLS]). Blood was collected via finger stick at 0 min (baseline), followed by beverage consumption, and again at 10 and 45 min. post consumption. Perceived hunger and thirst were measured by visual analog scale. Acylated ghrelin and copeptin concentrations were assessed by ELISA assay. Spearman's rank correlation coefficient was used to determine relationships. A repeated measures ANOVA was used to determine differences in ghrelin response. Results Perceived hunger scores differed by time (P &amp;lt; 0.0001) but not by beverage (P &amp;gt; 0.05) and there was no interaction. However, acylated ghrelin concentration did not differ by beverage or time (P &amp;gt; 0.05). Acylated ghrelin overall was 86.25 ± 92.30 pg/mL (mean ± SD). There was no relationship between perceived hunger and acylated ghrelin concentration at any time point or beverage (P &amp;gt; 0.05). Adjusting for gender or BMI had no impact. Perceived thirst differed by time (P &amp;lt; 0.0001) but not by beverage (P &amp;gt; 0.05). Copeptin concentrations are currently being analyzed via ELISA assay. Preliminary results for copeptin concentrations from participants consuming water and CNF did not differ by beverage or time. The average copeptin concentration measured from participants for these two beverages was 4.5 ± 4.0 ng/mL. After all samples are analyzed for copeptin, correlation will be run to determine if there is any relationship between copeptin, ghrelin, and perceived hunger and thirst. Conclusions Perceived hunger and thirst changed over time, regardless of beverage type. However, biomarker concentrations were not related to those changes. Perception of satiety may be influenced by other factors other than physiological signals. Funding Sources Funded by the College of Saint Benedict/Saint John's University Faculty Development Grant.

Enrichment of bread with beta-glucans or resistant starch induces similar glucose, insulin and appetite hormone responses in healthy adults.

β-Glucans (βG) and resistant starch (RS) are known for their effects on the improvement of glucose tolerance and enhancement of insulin sensitivity. Enrichment of bread with βG or RS was performed to examine potential postprandial benefits regarding gastrointestinal hormone responses. Ten healthy normoglycaemic adults participated in the study and were provided with either a glucose solution (reference food, GS) or bread enriched with β-glucans (βGB) (3.6g/30g available CHO) or bread enriched with resistant starch (RSB) (15% of total starch), with 1-week intervals in amounts that yielded 50g of available carbohydrates. Venous blood samples were collected before consumption and at 15, 30, 45, 60, 90, 120 and 180min postprandially. Glucose, insulin, ghrelin, glucagon-like peptide-1 (GLP-1) and peptide YY (PYY) responses as well as glycaemic index (GI) and subjective appetite ratings were evaluated. Ingestion of βGB and RSB elicited lower incremental area under the curve (iAUC) for glycaemic response compared to GS (P < 0.05). Both breads demonstrated a low GI (βGB: 48, RSB: 40). There were no significant differences in insulin response, ghrelin, GLP-1 or PYY between the two breads. A significantly lower desire to eat and higher fullness were detected 15min after βGB and RSB consumption and until 180min (P < 0.05 compared to GS). Enrichment of bread with either βG or RS produced a low GI product but the two breads were not significantly different in relation to insulin, ghrelin, GLP-1 and PYY responses. The development of bread products which cause improved metabolic effects is of great importance for the promotion of public health.

Visual stimulation with food pictures in the regulation of hunger hormones and nutrient deposition, a potential contributor to the obesity crisis.

Food cues affect hunger and nutritional choices. Omnipresent stimulation with palatable food contributes to the epidemics of obesity. The objective of the study was to investigate the impact of food cues on appetite-related hormones and to assess the functionality of the secreted hormones on macronutrient uptake in healthy subjects. Additionally, we aimed at verifying differences in the response of total and active ghrelin to stimulation with food pictures and to a meal followed by the stimulation. We were also interested in the identification of factors contributing to response to food cues. We recruited healthy, non-obese participants for two independent cross-over studies. During the first study, the subjects were presented random non-food pictures on the first day and pictures of foods on the second day of the study. Throughout the second study, following the picture session, the participants were additionally asked to drink a milkshake. Concentrations of blood glucose, triglycerides and hunger-related hormones were measured. The results showed that concentrations of several hormones measured in the blood are interdependent. In the case of ghrelin and gastric inhibitory peptide (GIP) as well as ghrelin and glucagon-like peptide-1 (GLP-1), this co-occurrence relies on the visual cues. Regulation of total ghrelin concentration following food stimulation is highly individual and responders showed upregulated total ghrelin, while the concentration of active ghrelin decreases following a meal. Protein content and colour intensity of food pictures reversely correlated with participants' rating of the pictures. We conclude that observation of food pictures influences the concentration of several appetite-related hormones. The close link of visual clues to physiological responses is likely of clinical relevance. Additionally, the protein content of displayed foods and green colour intensity in pictures may serve as a predictor of subjective attractiveness of the presented meal.

We are what we (think we) eat: The effect of expected satiety on subsequent calorie consumption

Varying expected satiety (ES) for equi-calorie portions of different foods can affect subsequent feelings of hunger and fullness and alter consumption. To our knowledge, no study has manipulated ES for an equal portion of the same solid food, subsequent appetite has not been measured >3 h and studies have not consistently measured later consumption. Further, it is not clear whether any changes in hunger, fullness or later consumption that stem from differing ES are the result of a psychological or physiological response. The aims of this study were to manipulate ES for the same solid food on two occasions in order to compare participants' appetitive responses over a 4-h inter-meal period, to measure later consumption, and to assess whether any effect of ES on these measures was related to a physiological (i.e. total ghrelin) response. Using a within-subjects design, 26 healthy participants had their ES for omelettes manipulated experimentally, believing that a 3-egg omelette contained either 2 (small condition) or 4 (large condition) eggs. When ES was higher (large condition) participants ate significantly fewer calories at a lunchtime test meal (mean difference = 69 kcal [± 95% CI 4–136]) and consumed significantly fewer calories throughout the day (mean difference = 167 kcal [± 95% CI 26–309]). The results show that there was a significant main effect of time on hunger and fullness, but no main effect of ‘portion size’ (p > .05). There was also a significant interaction between time and portion size for hunger. There was no evidence for any significant differences in appetite or consumtpion resulting from changes in total ghrelin. Overall, the data suggest that ES for a solid food can be manipulated and that, when given at breakfast, having a higher ES for a meal significantly reduces lunchtime and whole day caloric consumption.

Responses of gut and pancreatic hormones, bile acids, and fibroblast growth factor-21 differ to glucose, protein, and fat ingestion after gastric bypass surgery.

Postprandial gut hormone responses change after Roux-en-Y gastric bypass (RYGB), and we investigated the impact of glucose, protein, and fat (with and without pancreas lipase inhibition) on plasma responses of gut and pancreas hormones, bile acids, and fibroblast growth factor 21 (FGF-21) after RYGB and in nonoperated control subjects. In a randomized, crossover study 10 RYGB operated and 8 healthy weight-matched control subjects were administered 4 different 4-h isocaloric (200 kcal) liquid meal tests containing >90 energy (E)% of either glucose, protein (whey protein), or fat (butter with and without orlistat). The primary outcome was glucagon-like peptide-1 (GLP-1) secretion (area under the curve above baseline). Secondary outcomes included responses of peptide YY (PYY), glucose-dependent insulinotropic polypeptide (GIP), cholecystokinin (CCK), glicentin, neurotensin, ghrelin, insulin, glucagon, bile acids, and FGF-21. In the RYGB group the responses of GLP-1, GIP, glicentin, FGF-21, and C-peptide were increased after glucose compared with the other meals. The neurotensin and bile acids responses were greater after fat, while the glucagon and CCK responses were greater after protein ingestion. Furthermore, compared with control subjects, RYGB subjects had greater responses of total PYY after glucose, glucagon after glucose and fat, glicentin after glucose and protein, and GLP-1 and neurotensin after all meals, while GIP and CCK responses were lower after fat. Ghrelin responses did not differ between meals or between groups. Orlistat reduced all hormone responses to fat ingestion, except for ghrelin in the RYGB group. In conclusion, after RYGB glucose is a more potent stimulator of most gut hormones, especially for the marked increased secretion of GLP-1 compared with fat and protein.NEW & NOTEWORTHY We investigated the impact of glucose, protein, and fat meals on intestinal and pancreatic hormones, bile acid, and fibroblast growth factor 21 (FGF-21) secretion in gastric bypass-operated patients compared with matched nonoperated individuals. The fat meal was administered with and without a pancreas lipase inhibitor. We found that the impact of the different meals on gut hormones, bile, and FGF 21 secretion differ and was different from the responses observed in nonoperated control subjects.

Oxyntomodulin and Glicentin May Predict the Effect of Bariatric Surgery on Food Preferences and Weight Loss

Alterations in several gastrointestinal hormones are implicated in the postoperative suppression of food intake leading to weight loss after Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG). The aim was to evaluate changes in responses of gastrointestinal hormones after RYGB and SG and the associations of these changes with weight loss, energy intake, and food preferences. Forty-two subjects with severe obesity were included (32 RYGB; 10 SG). Postprandial responses of glicentin, oxyntomodulin, glucagon-like peptide-1 (GLP-1), peptide YY (PYY), and ghrelin were measured before and 6 months after surgery. Energy intake and energy density were assessed before and 6 months after surgery using a buffet meal test and weight loss was assessed 18 months after surgery. Postprandial concentrations of glicentin, oxyntomodulin, GLP-1, and ghrelin differed between RYGB and SG (all P ≤ .02). Enhanced responses of glicentin and oxyntomodulin predicted a greater weight loss (both P < .01) and were associated with a larger decrease in energy density (P ≤ .04). No associations were found for GLP-1, PYY, and ghrelin, and changes were not associated with changes in energy intake. When combing all hormones, 60%, 19%, and 33% of the variations in weight loss, energy intake, and energy density, respectively, could be explained. Postprandial responses of gastrointestinal hormones differed between RYGB and SG. Enhanced responses of glicentin and oxyntomodulin predicted a better weight loss and were associated with a decreased preference for energy-dense foods. Replication of these results could imply an opportunity to identify patients in need of additional support after surgical treatments of obesity.