Satiety signals and obesity

Nondietary psychological app program leads to sustained weight loss due to trained physiological satiety perception

Obese people are mostly unable to maintain successful weight loss after the end of a dietary change. One reason is that conventional weight reduction concepts neglect physiological hunger and satiety perception, leading to a relapse to previous eating habits on the long run. We examined the long-term efficacy of a psychological smartphone weight loss program, which avoids any dietary instructions and aims at relearning of satiety perception. Parameters of body weight alterations and psychological features, for example, satiety perception, food cravings, and emotional eating, were explored in a nonrandomized experimental study comprising 75 obese participants. Measurements occurred at baseline, two times during program application, as well as at 6- and 12-month follow-up. Participants displayed significant weight loss during the entire study period (p = .029) and showed an improved body composition at the 6-month follow-up (p = .018). These effects were associated with increased satiety perception, as well as reduced food cravings, and emotional eating habits. Notably, all improvements in measured parameters significantly sustained between the end of the program and the 12-month follow-up (p < .005 for all). Psychological relearning of satiety perception may outclass dietary approaches in terms of long-term efficiency.

Plasticity of gastrointestinal vagal afferents in terms of feeding-related physiology and pathophysiology

Gastrointestinal vagal afferents play an important role in communicating food related information from the gut to the brain. This information initiates vago-vagal reflexes essential for gut functions, including gut motility and secretions. These afferents also play a role in energy homeostasis, signalling the arrival, amount and nutrient composition of a meal to the central nervous system where it is processed ultimately leading to termination of a meal. Vagal afferent responses to food related stimuli demonstrate a high degree of plasticity, responding to short term changes in nutritional demand, such as the fluctuations that occur across a 24-hr or in response to a fast, as well as long term changes in energy demand, such as occurs during pregnancy. This plasticity is disrupted in disease states, such as obesity or chronic stress where there is hypo- and hypersensitivity of these afferents, respectively. Improved understanding of the plasticity of these afferents will enable identification of new treatment options for diseases associated with vagal afferent function.

The High-Dietary Insulin Load Score Is Associated With Elevated Level of Fasting Blood Sugar in Iranian Adult Men: Results From Fasa PERSIAN Cohort Study

Aim: The potential of different foods to induce postprandial hyperinsulinemia may be involved in the development of metabolic syndrome (MetS). We aimed to evaluate the association between dietary insulin indices and MetS in a large population of adults in Iran. Methods: A total of 6356 adults aged 35-70 years were included in the present cross-sectional study. A validated block-format 125-item semiquantitative food frequency questionnaire (FFQ) was used to obtain usual food intakes, and MetS was defined according to the International Diabetes Federation (IDF) and American Heart Association (AHA)/National Heart, Lung, and Blood Institute (NHLBI) criteria. Results: MetS was prevalent in 13.8% of participants. Mean age of the study participants was 46.58 ± 8.82 years, and mean body mass index (BMI) was 25.02 ± 4.60 kg/m2. Mean dietary insulin index (DII) and dietary insulin load (DIL) were 63.15 ± 7.57 and 168.253 ± 52.09, respectively. In the crude model, men in the highest DIL quartile were more likely to have hyperglycemia than those in the lowest quartile (OR: 1.75, 95% CI: 1.12-2.73, p trend = 0.04). This association remained significant and was even stronger after adjusting for potential confounders in model I (OR: 3.64, 95% CI: 1.57-8.47, p trend = 0.005) and further adjustment for BMI in model II (OR: 3.61, 95% CI: 1.55-8.44, p trend = 0.006). Conclusions: In healthy men, adherence to a high-DIL diet may be associated with a greater likelihood of having hyperglycemia. No statistically significant association was observed between insulin indices and the odds of having MetS.

Dietary insulin index, dietary insulin load and dietary patterns and the risk of metabolic syndrome in Hoveyzeh Cohort Study

Postprandial insulin secretion has been associated with metabolic disorders such as hyperlipidemia and type 2 diabetes. Therefore, we aimed to explore the relationship between dietary insulin indices and dietary pattern with the risk of Metabolic Syndrome (MetS). The participants of the present cross-sectional study were included among the individuals who participated in the Hoveyzeh Cohort Study (HCS). A total of 3905 Iranian adults, aged 35-70 years, are included in the current analysis. The Food Frequency Questionnaire (FFQ) is used to calculate the dietary Insulin Index (DII), Insulin Load (DIL), and dietary pattern. Dietary pattern was derived using Reduced-Rank Regression (RRR) based on intake of protein (g/day), fiber (g/day), fat (g/day), magnesium (mg/day), and dietary insulin index were considered as response variables. The Generalized Linear Model was used to obtain the odds ratio (OR) and 95% confidence interval (CI) for MetS based on gender, while considering quartiles of DIL, DII scores, and dietary pattern, adjusted for potential confounders. The mean ± SD of age and BMI of the participants in the top quartile of DIL were 45.72 ± 8.05 years and 28.25 ± 5.02 kg/m2, respectively. The mean ± SD of DII was 40.53 ± 4.06 and the mean ± SD of DIL was 117,986.1 ± 30,714.06. A significant positive association was observed between DIL and MetS in women after adjusting for confounding factors (OR: 1.51; 95% CI 1.16; 1.96). No significant association was seen between DIL, DII, and MetS among men. A derived dietary pattern characterized by high intakes of fruits, sugar, sweet deserts, Whole Grains, and dairy was associated with an increased risk of MetS in adjusted model2 among women (OR: 1.41; 95% CI 1.13; 1.75) and men in the same model (OR: 2.09; 95% CI 1.35; 3.21).However, the final model was significant just for men (OR: 2.08; 95% CI 1.35; 3.21) and not for women (OR: 1.24; 95% CI 0.96; 1.60). Our findings showed that adherence to a diet with a high insulin load can increase the risk of MetS in women. In addition, a derived dietary pattern by RRR indicated that a diet rich in fruits, sugar, sweet deserts, whole Grains, and dairy is related to increased risk of MetS in both men and women.

Association between dietary insulin index and load with cardiometabolic risk factors and risk of metabolic syndrome among the patients with type 2 diabetes: a cross-sectional study

BACKGROUND

This study aims to investigate the association between dietary insulin index (DII) and load (DIL) with cardiometabolic risk factors and the risk of developing metabolic syndrome (MetS) among patients with type 2 diabetes (T2DM).

METHODS

A cross-sectional study was conducted among 500 T2DM patients. Dietary intake was assessed using a validated food frequency questionnaire, and DII and DIL were calculated based on insulin response and energy content. Logistic regression analyses were performed to determine the odds ratios (ORs) for MetS.

RESULTS

Participants in the highest quartile of DIL had significantly higher odds of MetS (OR: 2.16; 95% CI: 1.02-4.25, P = 0.039) and hyperglycemia (OR: 1.69; 95% CI: 1.08-4.96, P = 0.032). We also discovered that patients in the highest quartile of DII had higher odds of MetS (OR: 1.69; 95% CI: 1.08-4.96, P = 0.034) and hyperglycemia (OR: 1.39; 95% CI: 1.04-4.12, P = 0.019). Furthermore, participants in the highest quartile of DIL (OR: 1.64; 95% CI: 1.00-2.59, P = 0.03) and DII (OR: 1.42; 95% CI: 1.05-1.95, P = 0.026) had higher odds of high waist circumference. When it came to hypertriglyceridemia, we found a significant association between DII and DIL only in the crude model, not the fully adjusted model. However, we didn't observe any significant association between DII and DIL with hypercholesteremia, Low HDL, and high blood pressure (P > 0.05).

CONCLUSION

Our study provides evidence suggesting that a higher DII and DIL may be associated with an increased risk of cardiometabolic risk factors and MetS in patients with T2DM.

The Possible Mediatory Role of Inflammatory Markers on the Association of Dietary Insulin Index and Insulin Load with Metabolic Syndrome in Women with Overweight and Obesity: A Cross-Sectional Study

Background

Metabolic syndrome (MetS) is associated with increased inflammation. Diet plays an important role in the prevention and management of MetS, while some dietary factors can also increase or decrease markers of systemic inflammation. In this study, we aimed to determine the mediated association of inflammatory markers induced by dietary insulin index (DII) and dietary insulin load (DIL) with MetS and its components.

Methods

This cross-sectional study was conducted with 219 women aged 18-28 years. Dietary intake was assessed by a 147-item food frequency questionnaire (FFQ). DII and DIL were calculated using the standard formula. The guidelines of the National Cholesterol Education Program's Adult Treatment Panel III were used to define MetS. Biochemical parameters and anthropometric and blood pressure measures were evaluated by standard protocols.

Results

After the adjustment for potential confounders, a marginally significant association was found between DII and MetS (OR = 2.11; 95% CI = 0.93-4.82; P = 0.06). However, we did not find a significant association between DIL and MetS. Furthermore, DII was significantly associated with waist circumference (WC) (OR = 1.67; 95% CI = 1.09- 4.03; P = 0.03) and marginally associated with triglyceride (TG) (OR = 1.10; 95% CI = 0.92-2.33; P = 0.07) and systolic blood pressure/diastolic blood pressure (SBP/DBP) (OR = 1.84; 95% CI = 0.85-3.99; P = 0.07). Moreover, there was a significant association between DIL and SBP/DBP (OR = 1.74; 95% CI = 1.54-5.61; P = 0.04). Also, we found that MCP-1 may have a mediatory role in the association between DII and DIL with MetS and several components of MetS. Hs-CRP did not have mediatory role in the association between DII and MetS. However, hs-CRP had a mediatory role in several MetS components. Furthermore, hs-CRP may have a mediatory role in the association of DIL with MetS and with some of its components.

Conclusions

A higher DII score may increase the odds of MetS and its components. DIL was not significantly associated with the odds of MetS, but the association of DIL and SBP/DBP was significant. MCP-1 may have a mediatory role in associations between DII and DIL with MetS. In addition, hs-CRP may have a mediatory role in the association between DIL and MetS.

Dietary insulin index and load and cardiometabolic risk factors among people with obesity: a cross-sectional study

BACKGROUND

The hypothesis of the effect of the insulinogenic effects of diet on the development of cardiometabolic disorders has been suggested, but limited data are available for adults with obesity. This study aimed to determine the association of dietary insulin index (DII) and dietary insulin load (DIL) with cardiometabolic risk factors among Iranian adults with obesity.

METHODS

The study was conducted with a total of 347 adults aged 20-50 years in Tabriz, Iran. Usual dietary intake was assessed through a validated 147-item food frequency questionnaire (FFQ). DIL was computed using published food insulin index (FII) data. DII was calculated by dividing DIL by the total energy intake of each participant. Multinational logistic regression analysis was performed to evaluate the association between DII and DIL and cardiometabolic risk factors.

RESULTS

Mean age of participants was 40.78 ± 9.23 y, and mean body mass index (BMI) was 32.62 ± 4.80 kg/m2. Mean of DII and DIL was 73.15 ± 37.60 and 196,242 ± 100,181. Participants with higher DII had higher BMI, weight, waist circumference (WC), and blood concentrations of triglyceride (TG) and Homeostasis model assessment insulin resistance index (HOMA-IR) (P < 0.05). After taking potential confounders into account, DIL was positively associated with MetS (OR: 2.58; 95% CI: 1.03-6.46), and high blood pressure (OR: 1.61; 95% CI: 1.13-6.56). Moreover, after adjustment for potential confounders, moderate DII was associated with increased odds of MetS (OR: 1.54, 95% CI: 1.36-4.21), high TG (OR, 1.25; 95% CI, 1.17-5.02), and high blood pressure (OR: 1.88; 95% CI: 1.06-7.86).

CONCLUSION

This population-based study revealed that adults with higher DII and DIL associated with cardiometabolic risk factors and consequently, replacement of high with low DII and DIL may have reduce the risk of cardiometabolic disorders. Further studies with longitudinal design are required to confirm these findings.

Associations between Insulin Index and dietary insulin load with cardiometabolic phenotype in the AZAR cohort population in north-western Iran: a cross-sectionalstudy

OBJECTIVES

Hyperinsulinaemia and insulin resistance are proposed as contributors to the incidence of cardiometabolic phenotypes (CMPs) with unhealthy metabolic status. This study analysed the association between dietary insulin load (DIL) and Dietary Insulin Index (DII) with CMPs in the AZAR cohort population.

DESIGN

This study was a cross-sectional analysis of the AZAR Cohort Study, beginning in 2014 and continuing to this date.

SETTING

The AZAR cohort is a part of an Iranian screening programme named the Persian cohort and involves participants living in the Shabestar region, Iran for at least 9 months.

PARTICIPANTS

A total of 15 006 participants agreed to partake in the study. We excluded participants with missing data (n=15), daily energy intake lower than 800 kcal (n=7) or higher than 8000 kcal (n=17), and cancer (n=85). Finally, 14 882 individuals remained.

PRIMARY AND SECONDARY OUTCOME MEASURES

The gathered information included the participants' demographic, dietary, anthropometric and physical activity data.

RESULTS

The frequency of DIL and DII significantly decreased from the first to fourth quartiles in metabolically unhealthy participants (p≤0.001). The mean values of DIL and DII were greater in metabolically healthy participants than in unhealthy ones (p<0.001). The results of the unadjusted model showed that the risks of unhealthy phenotypes in the fourth DIL quartile decreased by 0.21 (0.14-0.32) and 0.37 (0.33-0.43), respectively, compared with the first quartile. The same model showed the same risks for DII decreased by 0.18 (0.11-0.28) and 0.39 (0.34-0.45), respectively. The results in both genders were the same as all participants combined.

CONCLUSIONS

DII and DIL were correlated with a decreased OR of unhealthy phenotypes. We suggest the reason may be either a lifestyle change in metabolically unhealthy participants or elevated insulin secretion not being as detrimental as previously thought. Further studies can confirm these speculations.

Characterization of Gastrointestinal Hormone Dysfunction and Metabolic Pathophysiology in Experimental Spinal Cord Injury

Cardiometabolic disease is a leading complication of spinal cord injury (SCI) that contributes to premature all-cause cardiovascular morbidity and early death. Despite widespread reports that cardioendocrine disorders are more prevalent in individuals with SCI than those without disability, a well-defined pathophysiology has not been established. Autonomic dysfunction accompanying disruption of autonomic spinal tracts may contribute to dysregulation of energy metabolism via uncoupling of integrated hunger and satiation signals. In governing human feeding behaviors, these signals are controlled by a network of enteroendocrine cells that line the gastrointestinal (GI) tract. These cells regulate GI peptide release and autonomic systems that maintain direct neuroendocrine communication between the GI tract and appetite circuitry of the hypothalamus and brain stem. Here we investigate gene-expression and physiological changes in GI peptides and hormones, as well as changes in physiological response to feeding, glucose and insulin challenge and evaluate GI tissue cytoarchitecture following experimental SCI. Adult female mice (C57BL/6) were subjected to a severe SCI (65 kDyne) at T9, and a sham control group received laminectomy only. SCI results in chronic elevation of fasting plasma glucose levels, and an exaggerated glucose response after oral glucose and insulin tolerance test. Mice with SCI also exhibit significant alteration in gut hormone genes, plasma levels, physiological response to prandial challenge, and cell loss and gross tissue damage in the gut. These findings demonstrate that SCI has widespread effects on the GI system contributing to component Cardiometabolic disease risks factors and may inform future therapeutic and rehabilitation strategies in humans.

Dietary insulin index and insulin load in relation to hypertriglyceridemic waist phenotype and low brain derived neurotrophic factor in adults

Background

The evidence about the relation of the insulinemic potential of food with visceral obesity and brain-derived neurotrophic factor (BDNF) was limited. We aimed to investigate the relation of dietary insulin index (DII) and dietary insulin load (DIL) with hypertriglyceridemic waist phenotype (HTGW) and serum BDNF in Iranian adults.

Methods

This cross-sectional study included 528 middle-aged adults (45.6% women), using a multistage cluster random-sampling method. Dietary intakes were assessed using a validated semi-quantitative 168-item food frequency questionnaire. Blood samples were collected after 12 h of fasting for assessing the serum BDNF and triglyceride concentrations. HTGW was defined as triacylglycerol ≥ 150 mg/dL plus enlarged waist circumference. The values less than the first decile of serum BDNF were considered as the low level.

Results

Individuals in the top tertile of DIL, in comparison to those in the bottom tertile, had higher odds of HTGW in both crude (OR = 1.96, 95% CI: 1.14–3.37) and fully adjusted model (OR = 6.10, 95% CI: 1.58–23.53). However, the relation between DII and odds of HTGW was statistically insignificant in crude (OR = 1.30, 95% CI: 0.78–2.16) and maximally adjusted model (OR = 1.25, 95% CI: 0.65–2.40). After considering confounders, participants in the top tertile of DIL had marginally higher odds of having low BDNF values (OR = 2.00, 95% CI: 0.95–4.21). Nevertheless, the association between DII and odds of low BDNF values was statistically insignificant.

Conclusion

This population-based study demonstrated that adults with higher DIL had significantly higher chance of HTGW phenotype and slightly higher chance for low BDNF level. DII was not associated with HTGW phenotype or BDNF values.

A comprehensive review on the glucoregulatory properties of food-derived bioactive peptides

Diabetes mellitus, a group of metabolic disorders characterized by persistent hyperglycemia, affects millions of people worldwide and is on the rise. Dietary proteins, from a wide range of food sources, are rich in bioactive peptides with antidiabetic properties. Notable examples include AGFAGDDAPR, a black tea-derived peptide, VRIRLLQRFNKRS, a β-conglycinin-derived peptide, and milk-derived peptide VPP, which have shown antidiabetic effects in diabetic rodent models through variety of pathways including improving beta-cells function, suppression of alpha-cells proliferation, inhibiting food intake, increasing portal cholecystokinin concentration, enhancing insulin signaling and glucose uptake, and ameliorating adipose tissue inflammation. Despite the immense research on glucoregulatory properties of bioactive peptides, incorporation of these bioactive peptides in functional foods or nutraceuticals is widely limited due to the existence of several challenges in the field of peptide research and commercialization. Ongoing research in this field, however, is fundamental to pave the road for this purpose.

Association of Dietary Insulin Index and Dietary Insulin Load With Metabolic Health Status in Iranian Overweight and Obese Adolescents

Background

Limited data are available on the association of dietary insulin load (DIL) and dietary insulin index (DII) with health status in pediatrics. We aimed to investigate the relationship of DIL and DII with metabolic health status in Iranian overweight/obese adolescents.

Methods

In this cross-sectional study, using a multistage cluster random-sampling method, 203 overweight/obese adolescents (aged 12 to <18 years) were included. A validated 147-item food frequency questionnaire (FFQ) was used for a dietary intake assessment. Glycemic and lipid profile, blood pressure (BP), and anthropometric indices were measured. Participants were categorized as metabolically healthy obese (MHO) or metabolically unhealthy obese (MUO) using the two methods of the International Diabetes Federation (IDF) and a combination of IDF with Homeostasis Model Assessment Insulin Resistance (HOMA-IR).

Results

According to IDF and IDF/HOMA-IR strategies, 38.9% (n = 79) and 33.0% (n = 67) of participants belonged to MUO category. After adjustments for potential confounders, subjects in the highest tertile of DIL in comparison with those in the lowest tertile had the odds ratio (OR) values of 8.44 (95% CI: 2.24-31.78) and 5.86 (95% CI: 1.39-24.58) for MUO based on IDF and IDF/HOMA-IR definitions, respectively. Moreover, after considering potential confounders, adolescents in the highest tertile of DII, compared to the lowest tertile, were, respectively, 6.93 (OR: 6.93; 95% CI: 2.59-18.57) and 5.26 (OR: 5.26; 95% CI: 1.85-14.97) times more likely to be MUO, based on IDF and IDF/HOMA-IR definitions. A significant decreasing trend was observed for OR of MUO in tertiles of DIL and DII. The stratified analysis revealed that these associations were stronger in obese participants; in overweight subjects, the association was not independent of confounders.

Conclusion

This population-based study revealed that higher DIL and DII were strongly related to increased OR of MUO in Iranian adolescents, especially in obese participants. Further investigations, especially with a prospective design, are needed to affirm these findings.

Targeting Histamine and Histamine Receptors for the Precise Regulation of Feeding

Histamine has long been accepted as an anorexigenic agent. However, lines of evidence have suggested that the roles of histamine in feeding behaviors are much more complex than previously thought, being involved in satiety, satiation, feeding motivation, feeding circadian rhythm, and taste perception and memory. The functional diversity of histamine makes it a viable target for clinical management of obesity and other feeding-related disorders. Here, we update the current knowledge about the functions of histamine in feeding and summarize the underlying molecular and neural circuit mechanisms. Finally, we review the main clinical studies about the impacts of histamine-related compounds on weight control and discuss insights into future research on the roles of histamine in feeding. Despite the recent progress in histamine research, the histaminergic feeding circuits are poorly understood, and it is also worth verifying the functions of histamine receptors in a more spatiotemporally specific manner.

Higher dietary insulin load and index are not associated with the risk of metabolic syndrome and obesity in Iranian adults

BACKGROUND

Data about the relation between dietary insulin load (DIL) and dietary insulin index (DII) with metabolic syndrome (MetS) and obesity are scarce. Therefore, the present study aimed to examine the association of the insulinemic potential of the diet with MetS and obesity amongst Iranian adults.

METHODS

This cross-sectional study was conducted amongst 850 adults aged 20-59 years. Dietary data were collected using a 168-item food frequency questionnaire. DIL was calculated using a standard formula and DII was obtained by dividing DIL by the total energy intake of each participant. The guidelines of the International Diabetes Federation were used to define MetS. General obesity was considered as body mass index ≥ 30 kg/m² , and abdominal obesity as waist circumference ≥ 94 cm for men and ≥ 80 cm for women.

RESULTS

Mean DIL and DII values were 101 684 ± 54 802 and 49.4 ± 33.4, respectively. The mean age of participants was 44.9 ± 10.7 years and 36.8%, 28.5% and 48.8% of participants were suffering from MetS, general and abdominal obesity, respectively. In contrast with DIL (P = .73), participants in the last quartile of DII (P = .62) had lower odds of MetS than the first quartile. There were non-significant inverse associations between DIL (P = .91, P = .85) and DII (P = .59, P = .53) with odds of general and abdominal obesity before and after the adjustment of confounders, respectively.

CONCLUSIONS

We did not observe any significant association of DIL and DII with the risk of MetS and obesity amongst the Iranian population. Further prospective studies are needed to confirm the findings of this study.

Association of dietary total antioxidant capacity to anthropometry in healthy women: A cross-sectional study

OBJECTIVES

Reactive oxygen species level is a fundamental component in the pathogenesis of obesity that might be reduced by dietary antioxidants. Measurement of dietary total antioxidant capacity (DTAC) is regarded as a new holistic dietary index. Given the limited research on DTAC, the aim of this study was to examine the association of DTAC with obesity-related features in women.

METHODS

The present cross-sectional study included 627 female participants. Data on dietary intake were assessed using a validated food frequency questionnaire. DTAC was estimated through total reactive antioxidant potential (TRAP), Trolox equivalent antioxidant capacity (TEAC), and ferric reducing ability of plasma (FRAP). Anthropometric parameters (body mass index and waist circumference), were investigated using standard methods.

RESULTS

After adjustment for possible covariates, both TRAP and TEAC were significantly positively associated with obesity (TRAP: OR, 1.65; 95% confidence interval [CI], 1.04-2.63; P_trend, 0.03; TEAC: OR, 1.63; 95% CI, 1.01-2.63; P_trend, 0.04). However, there was no association between FRAP and obesity (OR_, 1.11; 95% CI, 0.64-1.93; P_trend, 0.68). Moreover, no relationship was found between different DTAC indices and waist circumference (TRAP: OR, 1.13; 95% CI, 0.70-1.80; P_trend, 0.60; TEAC: OR, 1.04; 95% CI, 0.64-1.69; P_trend, 0.87; FRAP: OR, 0.86; 95% CI, 0.49-1.51; P_trend, 0.62).

CONCLUSION

Women with higher DTAC scores had higher risk for obesity. No association was found between DTAC and waist circumference.

Association between dietary insulin index and load with obesity in adults

PURPOSE

Hyperinsulinemia is linked to the development of various chronic diseases, especially obesity given to the role of insulin responses in body fat accumulation; hence, the current study aimed to examine the association of insulinemic potential of the diet with general and abdominal obesity among a large population of Iranian adults.

METHODS

This cross-sectional study was carried out among 8691 adult participants aged 18-55 years. Dietary data were collected using a validated dish-based 106-item semi-quantitative food frequency questionnaire. Dietary insulin index (DII) was computed through considering food insulin index values published earlier. Dietary insulin load (DIL) was also calculated using a standard formula. Assessment of anthropometric measures was conducted through a self-administered questionnaire. General obesity was defined as body mass index ≥ 25 kg/m², and abdominal obesity as waist circumference ≥ 94 cm for men and ≥ 80 cm for women.

RESULTS

Mean age of study participants was 36.8 ± 8.1 years; 60.3% were women. Compared with the lowest quintile, women in the highest quintile of DIL were less likely to be abdominally obese (OR 0.73; 95% CI 0.57-0.92). Such significant association was not seen after controlling for potential confounders (OR 0.86; 95% CI 0.44-1.67). Neither in crude nor in adjusted models, we observed a significant association between DIL and general obesity among men and women. In terms of dietary insulin index, men in the top quintile of DII were more likely to be generally overweight or obese compared with those in the bottom quintile (OR 1.27; 95% CI 1.00-1.62). This association became non-significant after controlling for demographic characteristics (OR 1.14; 95% CI 0.84-1.56). Furthermore, in thefully adjusted model, women in the top quintile of DII were more likely to have general obesity compared with those in the bottom quintile (OR 1.40; 95% CI 1.07-1.84).

CONCLUSIONS

We found that adherence to a diet with a high DII was associated with greater odds of general obesity among women, but not in men. Although such information might help to draw conclusions on the practical relevance of the shown findings, further studies, specifically of prospective design, are warranted.

TMEM16B determines cholecystokinin sensitivity of intestinal vagal afferents of nodose neurons

The satiety effects and metabolic actions of cholecystokinin (CCK) have been recognized as potential therapeutic targets in obesity for decades. We identified a potentially novel Ca2+-activated chloride (Cl-) current (CaCC) that is induced by CCK in intestinal vagal afferents of nodose neurons. The CaCC subunit Anoctamin 2 (Ano2/TMEM16B) is the dominant contributor to this current. Its expression is reduced, as is CCK current activity in obese mice on a high-fat diet (HFD). Reduced expression of TMEM16B in the heterozygote KO of the channel in sensory neurons results in an obese phenotype with a loss of CCK sensitivity in intestinal nodose neurons, a loss of CCK-induced satiety, and metabolic changes, including decreased energy expenditure. The effect on energy expenditure is further supported by evidence in rats showing that CCK enhances sympathetic nerve activity and thermogenesis in brown adipose tissue, and these effects are abrogated by a HFD and vagotomy. Our findings reveal that Ano2/TMEM16B is a Ca2+-activated chloride channel in vagal afferents of nodose neurons and a major determinant of CCK-induced satiety, body weight control, and energy expenditure, making it a potential therapeutic target in obesity.

Postprandial gut hormone responses to Hass avocado meals and their association with visual analog scores in overweight adults: A randomized 3 × 3 crossover trial

OBJECTIVE

To evaluate changes in postingestive gut hormone concentrations from the consumption of Hass avocado by addition or inclusion to lunch test meals, and to examine their association with measures of appetite sensation.

METHODS

A randomized 3 × 3 crossover study was conducted with 26 healthy overweight adults. Participants consumed one of three test meals: avocado-free control (C); isoenergic avocado inclusive (AI); and, energy increased avocado added (AA) one week apart. Ghrelin, peptide YY_3-36 (PYY_3-36), gastric inhibitory peptide (GIP) and glucagon-like peptide-1 (GLP-1) concentrations were measured at specific times before and following the test meals. Appetite sensations (Hunger, Fullness, Satisfied, Desire, How Much) were self-assessed using a visual analog scale (VAS) tool at matching time points and a Composite VAS score was computed. Mixed models and repeated measures analysis were used to compare differences among the test meals for VAS measurements and gut hormones, and their associations were evaluated using regression analysis.

RESULTS

A decrease in the 3-hour GLP-1 area under the curve (AUC) was observed in the AA meal compared to the C meal (P = 0.03). Negative associations were found for PYY_3-36 and GIP for Hunger, Desire and How Much, and positive associations for Fullness, Satisfied and the Composite VAS score (all P < 0.001). For GLP-1, a negative association for Hunger and a positive association for Satisfied and the Composite VAS score (all P < 0.05) were noted.

CONCLUSIONS

Postprandial responses to PYY_3-36, GIP and GLP-1 concentrations were associated with VAS measures and the Composite VAS score following consumption of test meals in overweight adults.

High Fat With High Sucrose Diet Leads to Obesity and Induces Myodegeneration

Skeletal muscle utilizes both free fatty acids (FFAs) and glucose that circulate in the blood stream. When blood glucose levels acutely increase, insulin stimulates muscle glucose uptake, oxidation, and glycogen synthesis. Under these conditions, skeletal muscle preferentially oxidizes glucose while the oxidation of fatty acids (FAs) oxidation is reciprocally decreased. In metabolic disorders associated with insulin resistance, such as diabetes and obesity, both glucose uptake, and utilization muscle are significantly reduced causing FA oxidation to provide the majority of ATP for metabolic processes and contraction. Although the causes of this metabolic inflexibility or disrupted "glucose-fatty acid cycle" are largely unknown, a diet high in fat and sugar (HFS) may be a contributing factor. This metabolic inflexibility observed in models of obesity or with HFS feeding is detrimental because high rates of FA oxidation in skeletal muscle can lead to the buildup of toxic metabolites of fat metabolism and the accumulation of pro-inflammatory cytokines, which further exacerbate the insulin resistance. Further, HFS leads to skeletal muscle atrophy with a decrease in myofibrillar proteins and phenotypically characterized by loss of muscle mass and strength. Overactivation of ubiquitin proteasome pathway, oxidative stress, myonuclear apoptosis, and mitochondrial dysfunction are some of the mechanisms involved in muscle atrophy induced by obesity or in mice fed with HFS. In this review, we will discuss how HFS diet negatively impacts the various physiological and metabolic mechanisms in skeletal muscle.

Nutritional Health Considerations for Persons with Spinal Cord Injury

Chronic spinal cord injury (SCI) often results in morbidity and mortality due to all-cause cardiovascular disease (CVD) and comorbid endocrine disorders. Several component risk factors for CVD, described as the cardiometabolic syndrome (CMS), are prevalent in SCI, with the individual risks of obesity and insulin resistance known to advance the disease prognosis to a greater extent than other established risks. Notably, adiposity and insulin resistance are attributed in large part to a commonly observed maladaptive dietary/nutritional profile. Although there are no evidence-based nutritional guidelines to address the CMS risk in SCI, contemporary treatment strategies advocate more comprehensive lifestyle management that includes sustained nutritional guidance as a necessary component for overall health management. This monograph describes factors in SCI that contribute to CMS risks, the current nutritional profile and its contribution to CMS risks, and effective treatment strategies including the adaptability of the Diabetes Prevention Program (DPP) to SCI. Establishing appropriate nutritional guidelines and recommendations will play an important role in addressing the CMS risks in SCI and preserving optimal long-term health.

Impaired brain energy gain upon a glucose load in obesity

BACKGROUND

There is evidence that the brain's energy status is lowered in obesity despite of chronic hypercaloric nutrition. The underlying mechanisms are unknown. We hypothesized that the brain of obese people does not appropriately generate energy in response to a hypercaloric supply.

METHODS

Glucose was intravenously infused in 17 normal weights and 13 obese participants until blood glucose concentrations reached the postprandial levels of 7 mmol/L and 10 mmol/L. Changes in cerebral adenosine triphosphate (ATP) and phosphocreatine (PCr) content were measured by ³¹phosphorus magnetic resonance spectroscopy and stress hormonal measures regulating glucose homeostasis were monitored. Because vitamin C is crucial for a proper neuronal energy synthesis we determined circulating concentrations during the experimental testing.

RESULTS

Cerebral high-energy phosphates were increased at blood glucose levels of 7 mmol/L in normal weights, which was completely missing in the obese. Brain energy content moderately raised only at blood glucose levels of 10 mmol/L in obese participants. Vitamin C concentrations generally correlated with the brain energy content at blood glucose concentrations of 7 mmol/L.

CONCLUSIONS

Our data demonstrate an inefficient cerebral energy gain upon a glucose load in obese men, which may result from a dysfunctional glucose transport across the blood-brain barrier or a downregulated energy synthesis in mitochondrial oxidation processes. Our finding offers an explanation for the chronic neuroenergetic deficiency and respectively missing satiety perception in obesity.

Adverse effects of consuming high fat–sugar diets on cognition: implications for understanding obesity

There is increasing evidence for important roles of key cognitive processes, including attention, memory and learning, in the short-term decision making about eating. There is parallel evidence that people who are overweight or obese tend to perform worse on a variety of cognitive tasks. In this review, the evidence for these two ideas is summarised and then the idea that overconsumption of Western-style high-fat (HF)–high-sugar diets may underlie the association between obesity and poorer cognitive performance is explored. In particular, evidence in animals and human subjects that repeated consumption of HF or HF and sugar (HFS) diets leads to specific impairments in the functioning of the hippocampus, which underpin the consequent changes in cognition is summarised. These findings lead into the vicious cycle model (VCM), which suggests that these cognitive changes have knock-on negative effects for future appetite control, and evidence that altered hippocampal function is also associated with impaired appetite control is explored. The review concludes that there is consistent evidence in the animal literature and emerging evidence from human studies that supports this VCM. It is also noted, however, that to date studies lack the nutritional specificity needed to be able to translate these basic research findings into clear nutritional effects, and concludes that there is an urgent need for additional research to clarify the precise nature of the apparent effects of consuming HFS diets on cognition.

Effects of whole-grain rye porridge with added inulin and wheat gluten on appetite, gut fermentation and postprandial glucose metabolism: a randomised, cross-over, breakfast study

Whole-grain rye foods reduce appetite, insulin and sometimes glucose responses. Increased gut fermentation and plant protein may mediate the effect. The aims of the present study were to investigate whether the appetite-suppressing effects of whole-grain rye porridge could be enhanced by replacing part of the rye with fermented dietary fibre and plant protein, and to explore the role of gut fermentation on appetite and metabolic responses over 8 h. We conducted a randomised, cross-over study using two rye porridges (40 and 55 g), three 40-g rye porridges with addition of inulin:gluten (9:3; 6:6; 3:9 g) and a refined wheat bread control (55 g), served as part of complete breakfasts. A standardised lunch and an ad libitum dinner were served 4 and 8 h later, respectively. Appetite, breath hydrogen and methane, glucose, insulin and glucagon-like peptide-1 (GLP-1) responses were measured over 8 h. Twenty-one healthy men and women, aged 23-60 years, with BMI of 21-33 kg/m2 participated in this study. Before lunch, the 55-g rye porridges lowered hunger by 20 % and desire to eat by 22 % and increased fullness by 29 % compared with wheat bread (P<0·05). Breath hydrogen increased proportionally to dietary fibre content (P<0·05). Plasma glucose after lunch was 6 % lower after the 55-g rye porridges compared with wheat bread (P<0·05) and correlated to breath hydrogen (P<0·001). No differences were observed in ad libitum food intake, insulin or GLP-1. We conclude that no further increase in satiety was observed when replacing part of the rye with inulin and gluten compared with plain rye porridges.

MASP1, THBS1, GPLD1 and ApoA-IV are novel biomarkers associated with prediabetes: the KORA F4 study

AIMS/HYPOTHESIS

Individuals at a high risk of type 2 diabetes demonstrate moderate impairments in glucose metabolism years before the clinical manifestation of type 2 diabetes, a state called 'prediabetes'. In order to elucidate the pathophysiological processes leading to type 2 diabetes, we aimed to identify protein biomarkers associated with prediabetes.

METHODS

In a proteomics study, we used targeted selected reaction monitoring (SRM)-MS to quantify 23 candidate proteins in the plasma of 439 randomly selected men and women aged 47-76 years from the population-based German KORA F4 study. Cross-sectional associations of protein levels with prediabetes (impaired fasting glucose and/or impaired glucose tolerance), type 2 diabetes, glucose levels in both the fasting state and 2 h after an OGTT, fasting insulin and insulin resistance were investigated using regression models adjusted for technical covariables, age, sex, BMI, smoking, alcohol intake, physical inactivity, actual hypertension, triacylglycerol levels, total cholesterol/HDL-cholesterol ratio, and high-sensitivity C-reactive protein levels.

RESULTS

Mannan-binding lectin serine peptidase 1 (MASP1; OR per SD 1.77 [95% CI 1.26, 2.47]), thrombospondin 1 (THBS1; OR per SD 1.55 [95% CI 1.16, 2.07]) and glycosylphosphatidylinositol-specific phospholipase D1 (GPLD1; OR per SD 1.40 [95% CI 1.01, 1.94]) were positively associated with prediabetes, and apolipoprotein A-IV (ApoA-IV; OR per SD 0.75 [95% CI 0.56, 1.00]) was inversely associated with prediabetes. MASP1 was positively associated with fasting and 2 h glucose levels. ApoA-IV was inversely and THBS1 was positively associated with 2 h glucose levels. MASP1 associations with prediabetes and fasting glucose resisted Bonferroni correction. Type 2 diabetes associations were partly influenced by glucose-lowering medication.

CONCLUSIONS/INTERPRETATION

We discovered novel and independent associations of prediabetes and related traits with MASP1, and some evidence for associations with THBS1, GPLD1 and ApoA-IV, suggesting a role for these proteins in the pathophysiology of type 2 diabetes.

Atypical antipsychotics and effects on feeding: from mice to men

RATIONALE

So-called atypical antipsychotics (AAPs) are associated with varying levels of weight gain and associated metabolic disturbances, which in patients with serious mental illness (SMI) have been linked to non-compliance and poor functional outcomes. Mechanisms underlying AAP-induced metabolic abnormalities are only partially understood. Antipsychotic-induced weight gain may occur as a result of increases in food intake and/or changes in feeding.

OBJECTIVE

In this review, we examine the available human and preclinical literature addressing AAP-related changes in feeding behavior, to determine whether changes in appetite and perturbations in regulation of food intake could be contributing factors to antipsychotic-induced weight gain.

RESULTS

In general, human studies point to disruption by AAPs of feeding behaviors and food consumption. In rodents, increases in cumulative food intake are mainly observed in females; however, changes in feeding microstructure or motivational aspects of food intake appear to occur independent of sex.

CONCLUSIONS

The findings from this review indicate that the varying levels of AAP-related weight gain reflect changes in both appetite and feeding behaviors, which differ by type of AAP. However, inconsistencies exist among the studies (both human and rodent) that may reflect considerable differences in study design and methodology. Future studies examining underlying mechanisms of antipsychotic-induced weight gain are recommended in order to develop strategies addressing the serious metabolic side effect of AAPs.

Regulation of appetite, satiation, and body weight by enteroendocrine cells. Part 2: therapeutic potential of enteroendocrine cells in the treatment of obesity

Obesity is an epidemic and medical issue. Investigating the pathways regulating appetite, food intake, and body weight is crucial to find strategies for the prevention and treatment of obesity. In the context of therapeutic strategies, we focus here on the potential of enteroendocrine cells (EECs) and their secreted hormones in the regulation of body weight. We review the role of the enteroendocrine system during weight loss after lifestyle intervention or after bariatric surgery. We discuss the therapeutic potential of EECs and their hormones as targets for new treatment strategies. In fact, targeting nutrient receptors of EECs with a nutritional approach, pharmaceutical agents or prebiotics delivered to the lumen may provide a promising new approach.

Nesfatin-130-59 Injected Intracerebroventricularly Differentially Affects Food Intake Microstructure in Rats Under Normal Weight and Diet-Induced Obese Conditions

Nesfatin-1 is well-established to induce an anorexigenic effect. Recently, nesfatin-1₃₀₋₅₉, was identified as active core of full length nesfatin-1₁₋₈₂ in mice, while its role in rats remains unclear. Therefore, we investigated the effects of nesfatin-1₃₀₋₅₉ injected intracerebroventricularly (icv) on the food intake microstructure in rats. To assess whether the effect was also mediated peripherally we injected nesfatin-1₃₀₋₅₉ intraperitoneally (ip). Since obesity affects the signaling of various food intake-regulatory peptides we investigated the effects of nesfatin-1₃₀₋₅₉ under conditions of diet-induced obesity (DIO). Male Sprague–Dawley rats fed ad libitum with standard diet were icv cannulated and injected with vehicle (5 μl ddH₂O) or nesfatin-1₃₀₋₅₉ at 0.37, 1.1, and 3.3 μg (0.1, 0.3, 0.9 nmol/rat) and the food intake microstructure assessed using a food intake monitoring system. Next, naïve rats were injected ip with vehicle (300 μl saline) or nesfatin-1₃₀₋₅₉ (8.1, 24.3, 72.9 nmol/kg). Lastly, rats were fed a high fat diet for 10 weeks and those developing DIO were icv cannulated. Nesfatin-1 (0.9 nmol/rat) or vehicle (5 μl ddH₂O) was injected icv and the food intake microstructure assessed. In rats fed standard diet, nesfatin-1₃₀₋₅₉ caused a dose-dependent reduction of dark phase food intake reaching significance at 0.9 nmol/rat in the period of 4–8 h post injection (−29%) with the strongest reduction during the fifth hour (−75%), an effect detectable for 24 h (−12%, p < 0.05 vs. vehicle). The anorexigenic effect of nesfatin-1₃₀₋₅₉ was due to a reduction in meal size (−44%, p < 0.05), while meal frequency was not altered compared to vehicle. In contrast to icv injection, nesfatin-1₃₀₋₅₉ injected ip in up to 30-fold higher doses did not alter food intake. In DIO rats fed high fat diet, nesfatin-1₃₀₋₅₉ injected icv reduced food intake in the third hour post injection (−71%), an effect due to a reduced meal frequency (−27%, p < 0.05), while meal size was not altered. Taken together, nesfatin-1₃₀₋₅₉ is the active core of nesfatin-1₁₋₈₂ and acts centrally to reduce food intake in rats. The anorexigenic effect depends on the metabolic condition with increased satiation (reduction in meal size) under normal weight conditions, while in DIO rats satiety (reduction in meal frequency) is induced.

Appetite-related peptides in childhood and adolescence: role of ghrelin, PYY, and GLP-1

During childhood and adolescence, a number of factors, including age, puberty, sex, race, and body composition, may contribute to differences in satiety, food intake, and appetite-related peptides. These peptides include the orexigenic peptide ghrelin and anorexigenic gut peptides peptide YY (PYY) and glucagon-like peptide-1 (GLP-1). For example, lower fasting ghrelin levels, lower postprandial ghrelin suppression, and blunted PYY and GLP-1 responses to food intake could contribute to a dysregulation of appetite in already obese children and adolescents. Whereas, changes in these peptides observed during puberty could facilitate growth. A greater understanding of the major moderating factors of appetite-related peptides in the pediatric population is essential to improve interpretation of study findings and for effective tailoring of strategies targeting appetite control to individuals. While more studies are needed, there is some evidence to suggest that exercise-based lifestyle interventions could be a potential therapeutic strategy to improve appetite-peptide profiles in overweight and obese children and adolescents. The aim of this review is (i) to discuss the potential moderating factors of ghrelin, PYY, and GLP-1, including age and puberty, sex, race and body composition; and (ii) to examine the effects of exercise interventions on these appetite-related gut peptides in children and adolescents.

Influence of habitual physical activity on gastric emptying in healthy males and relationships with body composition and energy expenditure

Although a number of studies have examined the role of gastric emptying (GE) in obesity, the influences of habitual physical activity level, body composition and energy expenditure (EE) on GE have received very little consideration. In the present study, we compared GE in active and inactive males, and characterised relationships with body composition (fat mass and fat-free mass) and EE. A total of forty-four males (active n 22, inactive n 22; BMI 21-36 kg/m2; percentage of fat mass 9-42%) were studied, with GE of a standardised (1676 kJ) pancake meal being assessed by the [13C]octanoic acid breath test, body composition by air displacement plethysmography, RMR by indirect calorimetry, and activity EE (AEE) by accelerometry. The results showed that GE was faster in active compared with inactive males (mean half-time (t 1/2): active 157 (sd 18) and inactive 179 (sd 21) min, P< 0.001). When data from both groups were pooled, GE t 1/2 was associated with percentage of fat mass (r 0.39, P< 0.01) and AEE (r - 0.46, P< 0.01). After controlling for habitual physical activity status, the association between AEE and GE remained, but not that for percentage of fat mass and GE. BMI and RMR were not associated with GE. In summary, faster GE is considered to be a marker of a habitually active lifestyle in males, and is associated with a higher AEE level and a lower percentage of fat mass. The possibility that GE contributes to a gross physiological regulation (or dysregulation) of food intake with physical activity level deserves further investigation.

Chocolate-candy consumption and 3-year weight gain among postmenopausal U.S. women

OBJECTIVE

To test the hypothesis that greater chocolate-candy intake is associated with more weight gain in postmenopausal women.

METHODS

A prospective cohort study involved 107,243 postmenopausal American women aged 50-79 years (mean = 60.7) at enrollment in the Women's Health Initiative, with 3-year follow-up. Chocolate-candy consumption was assessed by food frequency questionnaire, and body weight was measured. Linear mixed models, adjusted for demographic, socio economic, anthropomorphic, and behavioral variables, were used to test our main hypotheses.

RESULTS

Compared with women who ate a 1 oz (∼28 g) serving of chocolate candy <1 per month, those who ate this amount 1 per month to <1 per week, 1 per week to < 3 per week and ≥3 per week showed greater 3-year prospective weight gains (kg) of 0.76 (95% CI: 0.66, 0.85), 0.95 (0.84, 1.06), and 1.40 (1.27, 1.53), respectively, (P for linear trend<0.0001). Each additional 1 oz/day was associated with a greater 3-year weight gain (kg) of 0.92 (0.80, 1.05). The weight gain in each chocolate-candy intake level increased as BMI increased above the normal range (18.5-25 kg/m(2)), and was inversely associated with age.

CONCLUSIONS

Greater chocolate-candy intake was associated with greater prospective weight gain in this cohort of postmenopausal women.

The acute effects of a new type of implantable gastric electrical stimulators featuring varied pulse widths on beagle dogs' food intake and gastric accommodation

BACKGROUND

To improve the therapeutic effects of gastric electrical stimulation (GES) for obesity, an animal experiment was conducted using a new type of stimulators. Proper parameters of GES were selected, and the impacts of GES on the food intake and gastric accommodation of canines were observed.

METHODS

Eight beagle dogs were operated on, and GES was performed on them. Firstly, GES was performed to determine the right parameters according to symptoms. Secondly, the so selected parameters were used in a 3-day GES procedure, during which process food intake, body weight, and symptoms were recorded. Thirdly, the gastric capacities before and after GES with different pulse widths were measured by means of a barostat.

RESULTS

The selected parameters varied for each dog, with the pulse widths ranging from 0.3 to 6 ms. The food consumption after GES dropped significantly as compared with the amount observed in the sham stimulation. Tolerance to stimulation could be observed during GES. The post-GES gastric fundus capacity increased evidently in comparison with the capacity before GES, suggesting significant distention as compared with sham stimulation. Given an increment of 2 ms in the pulse width twice, the gastric capacity continued to distend each time.

CONCLUSIONS

GES featuring pulse trains with wider and individualized pulse widths could inhibit food consumption of dogs. The stimulation parameters should be selected individually and adjusted periodically. GES of this mode could also increase the fasting gastric capacity with certain dose-related effects. The new type of stimulators may be more suitable for the treatment of human obesity than traditional stimulators.

Different types of soluble fermentable dietary fibre decrease food intake, body weight gain and adiposity in young adult male rats

BACKGROUND

Dietary fibre-induced satiety offers a physiological approach to body weight regulation, yet there is lack of scientific evidence. This experiment quantified food intake, body weight and body composition responses to three different soluble fermentable dietary fibres in an animal model and explored underlying mechanisms of satiety signalling and hindgut fermentation.

METHODS

Young adult male rats were fed ad libitum purified control diet (CONT) containing 5% w/w cellulose (insoluble fibre), or diet containing 10% w/w cellulose (CELL), fructo-oligosaccharide (FOS), oat beta-glucan (GLUC) or apple pectin (PECT) (4 weeks; n = 10/group). Food intake, body weight, and body composition (MRI) were recorded, final blood samples analysed for gut satiety hormones, hindgut contents for fermentation products (including short-chain fatty acids, SCFA) and intestinal tissues for SCFA receptor gene expression.

RESULTS

GLUC, FOS and PECT groups had, respectively, 10% (P < 0.05), 17% (P < 0.001) and 19% (P < 0.001) lower food intake and 37% (P < 0.01), 37% (P < 0.01) and 45% (P < 0.001) lower body weight gain than CONT during the four-week experiment. At the end they had 26% (P < 0.05), 35% (P < 0.01) and 42% (P < 0.001) less total body fat, respectively, while plasma total glucagon-like peptide-1 (GLP-1) was 2.2-, 3.2- and 2.6-fold higher (P < 0.001) and peptide tyrosine tyrosine (PYY) was 2.3-, 3.1- and 3.0-fold higher (P < 0.001). There were no differences in these parameters between CONT and CELL. Compared with CONT and CELL, caecal concentrations of fermentation products increased 1.4- to 2.2-fold in GLUC, FOS and PECT (P < 0.05) and colonic concentrations increased 1.9- to 2.5-fold in GLUC and FOS (P < 0.05), with no consistent changes in SCFA receptor gene expression detected.

CONCLUSIONS

This provides animal model evidence that sustained intake of three different soluble dietary fibres decreases food intake, weight gain and adiposity, increases circulating satiety hormones GLP-1 and PYY, and increases hindgut fermentation. The presence of soluble fermentable fibre appears to be more important than its source. The results suggest that dietary fibre-induced satiety is worthy of further investigation towards natural body weight regulation in humans.

Deletion of leptin signaling in vagal afferent neurons results in hyperphagia and obesity

The vagal afferent pathway senses hormones released from the gut in response to nutritional cues and relays these signals to the brain. We tested the hypothesis that leptin resistance in vagal afferent neurons (VAN) is responsible for the onset of hyperphagia by developing a novel conditional knockout mouse to delete leptin receptor selectively in sensory neurons (Nav1.8/LepR (fl/fl) mice). Chow fed Nav1.8/LepR (fl/fl) mice weighed significantly more and had increased adiposity compared with wildtype mice. Cumulative food intake, meal size, and meal duration in the dark phase were increased in Nav1.8/LepR (fl/fl) mice; energy expenditure was unaltered. Reduced satiation in Nav1.8/LepR (fl/fl) mice is in part due to reduced sensitivity of VAN to CCK and the subsequent loss of VAN plasticity. Crucially Nav1.8/LepR (l/fl) mice did not gain further weight in response to a high fat diet. We conclude that disruption of leptin signaling in VAN is sufficient and necessary to promote hyperphagia and obesity.

A new flexible plug and play scheme for modeling, simulating, and predicting gastric emptying

BACKGROUND

In-silico models that attempt to capture and describe the physiological behavior of biological organisms, including humans, are intrinsically complex and time consuming to build and simulate in a computing environment. The level of detail of description incorporated in the model depends on the knowledge of the system's behavior at that level. This knowledge is gathered from the literature and/or improved by knowledge obtained from new experiments. Thus model development is an iterative developmental procedure. The objective of this paper is to describe a new plug and play scheme that offers increased flexibility and ease-of-use for modeling and simulating physiological behavior of biological organisms.

METHODS

This scheme requires the modeler (user) first to supply the structure of the interacting components and experimental data in a tabular format. The behavior of the components described in a mathematical form, also provided by the modeler, is externally linked during simulation. The advantage of the plug and play scheme for modeling is that it requires less programming effort and can be quickly adapted to newer modeling requirements while also paving the way for dynamic model building.

RESULTS

As an illustration, the paper models the dynamics of gastric emptying behavior experienced by humans. The flexibility to adapt the model to predict the gastric emptying behavior under varying types of nutrient infusion in the intestine (ileum) is demonstrated. The predictions were verified with a human intervention study. The error in predicting the half emptying time was found to be less than 6%.

CONCLUSIONS

A new plug-and-play scheme for biological systems modeling was developed that allows changes to the modeled structure and behavior with reduced programming effort, by abstracting the biological system into a network of smaller sub-systems with independent behavior. In the new scheme, the modeling and simulation becomes an automatic machine readable and executable task.

Optogenetic and chemogenetic insights into the food addiction hypothesis

Obesity is clinically diagnosed by a simple formula based on the weight and height of a person (body mass index), but is associated with a host of other behavioral symptoms that are likely neurological in origin. In recent years, many scientists have asked whether similar behavioral and cognitive changes occur in drug addiction and obesity, lending many to discuss the potential for “food addiction”. Advances in understanding the circuitry underlying both feeding behaviors and drug addiction may allow us to consider this question from the viewpoint of neural circuits, to complement behavioral perspectives. Here, we review advances in understanding of these circuits and use them to consider whether drawing comparisons to drug addiction is helpful for understanding certain forms of obesity.

An application of Pavlovian principles to the problems of obesity and cognitive decline

An enormous amount of research has been aimed at identifying biological and environmental factors that are contributing to the current global obesity pandemic. The present paper reviews recent findings which suggest that obesity is attributable, at least in part, to a disruption of the Pavlovian control of energy regulation. Within our framework, this disruption occurs when (a) consumption of sweet-tasting, but low calorie or noncaloric, foods and beverages reduces the ability of sweet tastes to predict the postingestive caloric consequences of intake and (b) consuming diets high in saturated fat and sugar (a.k.a., Western diet) impairs hippocampal-dependent learning and memory processes that are involved with the use of interoceptive "satiety" signals to anticipate when food and eating are not followed by appetitive postingestive outcomes. The paper concludes with discussion of a "vicious-cycle" model which links obesity to cognitive decline.