Issues in Measuring and Interpreting Human Appetite (Satiety/Satiation) and Its Contribution to Obesity

Thylakoid supplementation and hunger and fullness perception: a systematic review and dose-response meta-analysis of randomized controlled trials

CONTEXT

It has been suggested that thylakoid supplementation could be associated with favorable changes in appetite. However, the present trials are inconsistent.

OBJECTIVE

This systematic review and meta-analysis aimed to investigate whether thylakoid supplementation is effective in hunger/fullness changes.

DATA SOURCES

A comprehensive literature search was performed before conducting a systematic search in PubMed, Scopus, and ISI Web of Sciences databases up to May 2023.

DATA EXTRACTION

Of the 262 articles found, 5 articles that measured hunger fullness expressed as ratings on the visual analog scale (VAS) for appetite analyses were selected and thoroughly examined. Relevant information, such as the authors' names, year of publication, country of origin, study design, number and status of participants, intervention dosage and type, study duration, assay used, and key findings, was extracted from these articles. The Jadad scale was used to evaluate the quality of studies.

DATA ANALYSIS

The data were obtained using STATA version 13 (StataCorp). Effect sizes were reported as weighted mean differences (WMDs) and 95% confidence intervals (CIs). Subgroup analyses were performed to estimate whether the effects of thylakoid supplementation on hunger and fullness varied according to dose, intervention duration, baseline population age and body mass index, baseline hunger and fullness, total sample size, and study quality. Fractional polynomial modeling was carried out to estimate time- and dose-response meta-analysis of the association between thylakoid and satiety and fullness. The meta-analysis also suggests a significant association between the combination of thylakoids with meals and reduced hunger (WMD: -2.415 mm; 95% CI: -3.544, -1.287; P < 0.001) and increased fullness (WMD: +4.602 mm; 95% CI: 2.356, 6.848; P < 0.001). Further analysis showed that thylakoid supplementation with 2 doses of 5 g/day (P = 0.002) and 7.4 g/day (P = 0.021) is more effective in reducing the feeling of hunger during an intervention of less than 56 days (P < 0.001) and with a lower level of hunger (VAS <45 mm, P < 0.001). Furthermore, a significant increase in the perception of fullness was found at a duration of less than 84 days (P < 0.001) and baseline fullness of more than 45 mm (P < 0.001).

CONCLUSIONS

Supplementation with thylakoid shows favorable effects on reducing hunger and increasing fullness during a shorter intervention duration. Further trials are required to shed light on this relationship.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42023432429.

Meat- and plant-based products induced similar satiation which was not affected by multimodal augmentation

Little is known about how plant-based products influence satiation compared to corresponding meat-based products. As augmented reality (AR) intensifies sensory experiences, it was hypothesized to improve satiation. This study compared satiation between intake of meatballs and plant-based balls and plant-based balls intensified with AR for visual, olfactory, and haptic sensory properties. Intake order of the meatballs, plant-based balls, and augmented plant-based balls, eaten on separate days, was randomized. Satiation was measured from twenty-eight non-obese adults as ad libitum intake of the balls and extra snacks, and as subjective appetite sensations. Liking and wanting to eat the products were also investigated. There were no differences between the products in satiation. Before tasting the augmented plant-based balls were less liked than the meatballs (p = 0.002) or plant-based balls (p = 0.046), but after eating the first ball or eating the ad libitum number of balls the differences in liking disappeared. Wanting evaluations were similar for each product and decreased during eating (p < 0.001). A group of participants susceptible to AR was found (n = 11), described by decreased intake when augmentation was applied. Among the sub-group, wanting to eat the augmented balls was lower before tasting (p = 0.019) and after eating the first ball (p = 0.002) and appetite was less suppressed after eating the balls ad libitum (p = 0.01), when compared to non-susceptible participants. We conclude that meatballs and plant-based balls were equal in inducing satiation, and multisensory augmentation did not influence satiation. However, the augmentation decreased liking evaluations before tasting. Further studies are needed to explore differences between consumer groups in susceptibility to augmentation.

Neurohormonal response patterns to hunger, satiation, and postprandial fullness in normal weight, anorexia nervosa, and obesity

BACKGROUND

Food intake is regulated by homeostatic and hedonic systems that interact in a complex neuro-hormonal network. Dysregulation in energy intake can lead to obesity (OB) or anorexia nervosa (AN). However, little is known about the neurohormonal response patterns to food intake in normal weight (NW), OB, and AN.

MATERIAL & METHODS

During an ad libitum nutrient drink (Ensure®) test (NDT), participants underwent three pseudo-continuous arterial spin labeling (pCASL) MRI scans. The first scan was performed before starting the NDT after a > 12 h overnight fast (Hunger), the second after reaching maximal fullness (Satiation), and the third 30-min after satiation (postprandial fullness). We measured blood levels of ghrelin, cholecystokinin (CCK), glucagon-like peptide (GLP-1), and peptide YY (PYY) with every pCASL-MRI scan. Semiquantitative cerebral blood flow (CBF) maps in mL/100 gr brain/min were calculated and normalized (nCBF) with the CBF in the frontoparietal white matter. The hypothalamus (HT), nucleus accumbens [NAc] and dorsal striatum [DS] were selected as regions of interest (ROIs).

RESULTS

A total of 53 participants, 7 with AN, 17 with NW (body-mass index [BMI] 18.5-24.9 kg/m2 ), and 29 with OB (BMI ≥30 kg/m2 ) completed the study. The NW group had a progressive decrease in all five ROIs during the three stages of food intake (hunger, satiation, and post-prandial fullness). In contrast, participants with OB showed a minimal change from hunger to postprandial fullness in all five ROIs. The AN group had a sustained nCBF in the HT and DS, from hunger to satiation, with a subsequent decrease in nCBF from satiation to postprandial fullness. All three groups had similar hormonal response patterns with a decrease in ghrelin, an increase in GLP-1 and PYY, and no change in CCK.

CONCLUSION

Conditions of regulated (NW) and dysregulated (OB and AN) energy intake are associated with distinctive neurohormonal activity patterns in response to hunger, satiation, and postprandial fullness.

Acute effects of exercise intensity on butyrylcholinesterase and ghrelin in young men: A randomized controlled study

Background/objectives

Butyrylcholinesterase (BChE), a liver-derived enzyme that hydrolyzes acylated ghrelin to des-acylated ghrelin, may trigger a potential mechanism responsible for the acute exercise-induced suppression of acylated ghrelin. However, studies examining the effects of an acute bout of high-intensity exercise on BChE and acylated ghrelin have yielded inconsistent findings. This study aimed to examine the acute effects of exercise intensity on BChE, acylated ghrelin and des-acylated ghrelin concentrations in humans.

Methods

Fifteen young men (aged 22.7 ± 1.8 years, mean ± standard deviation) completed three, half-day laboratory-based trials (i.e., high-intensity exercise, low-intensity exercise and control), in a random order. In the exercise trials, the participants ran for 60 min (from 09:30 to 10:30) at a speed eliciting 70 % (high-intensity) or 40 % (low-intensity) of their maximum oxygen uptake and then rested for 90 min. In the control trial, participants sat on a chair for the entire trial (from 09:30 to 12:00). Venous blood samples were collected at 09:30, 10:00, 10:30, 11:00, 11:30 and 12:00.

Results

The BChE concentration was not altered over time among the three trials. Total acylated and des-acylated ghrelin area under the curve during the first 60 min (i.e., from 0 min to 60 min) of the main trial were lower in the high-intensity exercise trial than in the control (acylated ghrelin, mean difference: 62.6 pg/mL, p < 0.001; des-acylated ghrelin, mean difference: 31.4 pg/mL, p = 0.035) and the low-intensity exercise trial (acylated ghrelin, mean difference: 87.7 pg/mL, p < 0.001; des-acylated ghrelin, mean difference: 43.0 pg/mL, p = 0.042).

Conclusion

The findings suggest that BChE may not be involved in the modulation of ghrelin even though lowered acylated ghrelin concentration was observed after high-intensity exercise.

Effects of pre-exercise high and low glycaemic index meals on substrate metabolism and appetite in middle-aged women

Few studies have examined the influence of pre-exercise meals with different glycaemic indices (GIs) on substrate oxidation and non-homeostatic appetite (i.e. food reward) in adults of various ages and ethnicities. We aimed to examine the effects of pre-exercise high and low GI meals on substrate oxidation and food reward in middle-aged Japanese women. This randomised crossover trial included fifteen middle-aged women (aged 40⋅9 ± 6⋅5 years, mean ± sd). The participants consumed a high or low GI breakfast at 09.00 and rested until 11.00. Thereafter, participants performed a 60-min walk at 50 % of their estimated maximum oxygen uptake (11.00-12.00) and rested until 13.00. Expired gas samples were collected every 30 min prior to walking, and samples were collected continuously throughout the walking and post-walking periods. Blood samples and subjective appetite ratings were collected every 30 min, except during walking. The Leeds Food Preference Questionnaire in Japanese (LFPQ-J) was used to assess food reward at 09.00, 10.00, and 13.00 h. The cumulative fat oxidation during exercise was higher in the low GI trial than in the high GI trial (P = 0⋅03). The cumulative carbohydrate oxidation during walking was lower in the low GI trial than in the high GI trial (P = 0⋅01). Trial-by-time interactions were not found for any food-reward parameters between trials. Low GI meals elicited enhanced fat oxidation during a subsequent 60-min walk in middle-aged women. However, meals with different GIs did not affect food reward evaluated over time in the present study.

Obesity-induced and weight-loss-induced physiological factors affecting weight regain

Weight regain after successful weight loss resulting from lifestyle interventions is a major challenge in the management of overweight and obesity. Knowledge of the causal mechanisms for weight regain can help researchers and clinicians to find effective strategies to tackle weight regain and reduce obesity-associated metabolic and cardiovascular complications. This Review summarizes the current understanding of a number of potential physiological mechanisms underlying weight regain after weight loss, including: the role of adipose tissue immune cells; hormonal and neuronal factors affecting hunger, satiety and reward; resting energy expenditure and adaptive thermogenesis; and lipid metabolism (lipolysis and lipid oxidation). We describe and discuss obesity-associated changes in these mechanisms, their persistence during weight loss and weight regain and their association with weight regain. Interventions to prevent or limit weight regain based on these factors, such as diet, exercise, pharmacotherapy and biomedical strategies, and current knowledge on the effectiveness of these interventions are also reviewed.

Reasons individuals stop eating questionnaire (RISE-Q) among adults in the United Arab Emirates

The relationship between obesity and satiation is complex and bidirectional. Understanding differences in reasons for meal termination may enhance our understanding of overeating risks and susceptibility to overconsumption. This study aimed to investigate the reasons why individuals in the UAE stop eating. A cross-sectional web-based study was conducted among adults ≥18 years in the UAE (n = 1482). Using a self-administered online questionnaire, we collected information on sociodemographic characteristics, lifestyle habits, and eating behavior using the Reasons Individuals Stop Eating-Questionnaire (RISE-Q-15) used twice for breakfast/main meal. The items were categorized into five scales; decreased food appeal (DFA), physical satisfaction (PS), planned amount (PA), self-consciousness (SC), and decreased priority of eating (DPE). All items were scored from 1 to 7 ranging between 3 to 21 on each scale. A paired t-test was used to evaluate the difference between the RISE-Q scores on each scale concerning the two meals. The main reason why participants stopped eating breakfast was under the PS scale (14.91 ± 3.72), followed by the PA scale (14.58 ± 3.00). The main reason why participants stopped eating main meals was under the PS scale (14.78 ± 3.56), followed by the PA scale (14.77 ± 43.81). The mean score of the DPE scale was significantly higher for breakfast than the main meal (p = 0.038). More than half of the participants reported an average eating rate (58.7%). Pearson's chi-square analysis revealed that the eating rate was dependent on BMI (p<0.001). Considering individual mealtimes and addressing factors related to PS and PA of food is crucial when designing nutrition interventions aiming to promote healthy eating habits among adults in the UAE.

The New Zealand eating behavior questionnaire - Validation study for a novel assessment tool to describe actionable eating behavior traits

Individualised management of obesity remains challenging and, to date, most treatment is based on clinical judgement. This study aimed to develop and validate a novel questionnaire-based tool to identify three pre-defined eating behavior (EB) traits, emotional eating, reduced satiety (constant hunger) and reduced satiation (feasters) that may predict selective medication response given their targeted actions. We recruited 977 individuals from a tertiary academic diabetes clinic to participate in this two-phase validation study. Participants self-reported weight management activities and were asked to self-assess their EB characteristics. The initial questionnaire included 42 visual analogue scale questions. In Phase I, 729 participants completed the questionnaire, including Māori (11.8%) and Pacific peoples (19.3%). After random division of the study sample, Exploratory Factor Analysis (EFA) confirmed a three-factor model as the best fit. Stepwise removal of items with inadequate factor loading retained 27 of 42 items, which accounted for 96% of the variance. Confirmatory Factor Analysis (CFA), performed on the second half of the sample, demonstrated good model fit with the final 27-item questionnaire. Internal consistency was high for factor (α = 0.82-0.95) and demographic subgroups, and similar to those obtained in the EFA. Test-retest reliability in a subset of 399 participants who repeated the questionnaire after a four-week interval (Phase II) showed moderate to good reliability. Participants classified into one of three EB types based on the highest median score among the factors. Test-retest reliability was robust for emotional eaters (71.25%) and constant hunger (68.9%). The correlation between aggregate EB score (sum of three EB scores) and BMI was significant (Spearman rho = 0.314, P = .0005). The questionnaire reliably identified three distinct EB traits, which may be informative for precision medicine applications for obesity management.

Whey Protein-Enriched and Carbohydrate-Rich Breakfasts Attenuate Insulinemic Responses to an ad libitum Lunch Relative to Extended Morning Fasting: A Randomized Crossover Trial

BACKGROUND

Typical breakfast foods are rich in carbohydrate, so they not only elevate blood glucose during the morning, but also elicit a second-meal effect that can attenuate blood glucose responses in the afternoon.

OBJECTIVES

To determine whether a reduced-carbohydrate protein-enriched breakfast can elicit similar effects on glucose control later in the day but without hyperglycemia in the morning.

METHODS

In a randomized crossover design, 12 healthy men and women (age 22 ± 2 y, BMI 24.1 ± 3.6 kg·m-2; Mean ± SD) completed 3 experimental conditions. In all conditions, participants consumed an ad libitum lunch at 1200 ± 1 h but differed in terms of whether they had fasted all morning (control) or had consumed a standardized porridge breakfast at 0900 ± 1 h (320 ± 50 kcal; prescribed relative to resting metabolic rate) that was either carbohydrate-rich (50 ± 10 g CHO) or protein-enriched (that is, isoenergetic substitution of carbohydrate for 15 g whey protein isolate).

RESULTS

The protein-enriched breakfast reduced the morning glycemic response (iAUC 87 ± 36 mmol·L-1·180 min) relative to the carbohydrate-rich breakfast (119 ± 37 mmol·L-1·180 min; P = 0.03). Despite similar energy intake at lunch in all 3 conditions (protein-enriched 769 ± 278 kcal; carbohydrate-rich 753 ± 223 kcal; fasting 790 ± 227 kcal), postlunch insulinemic responses were markedly attenuated when breakfasts had been consumed that were either protein-enriched (18.0 ± 8.0 nmol·L-1·120 min; P = 0.05) or carbohydrate-rich (16.0 ± 7.7 nmol·L-1·120 min; P = 0.005), relative to when lunch was consumed in an overnight fasted state (26.9 ± 13.5 nmol·L-1·120 min).

CONCLUSIONS

Breakfast consumption attenuates insulinemic responses to a subsequent meal, achieved with consumption of energy-matched breakfasts typically high in carbohydrates or enriched with whey protein isolate relative to extended morning fasting.

TRIAL REGISTRATION NUMBER

NCT03866720 (clinicaltrials.gov).

Benefits of Fiber-Enriched Foods on Satiety and Parameters of Human Well-Being in Adults with and without Cardiometabolic Risk

Consumption of fiber-rich foods is linked to beneficial effects on chronic diseases and gut health, while implications towards improving satiety and parameters of well-being remain unclear. A randomized placebo-controlled intervention study was conducted to compare the effects of fiber-enriched foods to their non-enriched counterparts in adults over a 12-week period on selected clinical parameters-satiety, quality of life, body sensation, and life satisfaction-subjective health status, and importance of diet for well-being. Quality of life (QOL) differed significantly between intervention and control groups at baseline, throughout, and at the end of the study. No effects on satiety, satisfaction with life, or the importance of diet for well-being could be shown between groups. With higher fiber intake, body sensation ratings increased. A higher BMI was significantly associated with lower-body sensation, subjective health status and quality of life. Fiber-enriched foods do not seem to affect feeling of satiety or parameters of well-being. Larger samples and additional methods are necessary to fully explore the effect of increased fiber intake on patient-related outcomes in more detail.

Eating Behavior and Satiety With Virtual Reality Meals Compared With Real Meals: Randomized Crossover Study

BACKGROUND

Eating disorders and obesity are serious health problems with poor treatment outcomes and high relapse rates despite well-established treatments. Several studies have suggested that virtual reality technology could enhance the current treatment outcomes and could be used as an adjunctive tool in their treatment.

OBJECTIVE

This study aims to investigate the differences between eating virtual and real-life meals and test the hypothesis that eating a virtual meal can reduce hunger among healthy women.

METHODS

The study included 20 healthy women and used a randomized crossover design. The participants were asked to eat 1 introduction meal, 2 real meals, and 2 virtual meals, all containing real or virtual meatballs and potatoes. The real meals were eaten on a plate that had been placed on a scale that communicated with analytical software on a computer. The virtual meals were eaten in a room where participants were seated on a real chair in front of a real table and fitted with the virtual reality equipment. The eating behavior for both the real and virtual meals was filmed. Hunger was measured before and after the meals using questionnaires.

RESULTS

There was a significant difference in hunger from baseline to after the real meal (mean difference=61.8, P<.001) but no significant change in hunger from before to after the virtual meal (mean difference=6.9, P=.10). There was no significant difference in food intake between the virtual and real meals (mean difference=36.8, P=.07). Meal duration was significantly shorter in the virtual meal (mean difference=-5.4, P<.001), which led to a higher eating rate (mean difference=82.9, P<.001). Some participants took bites and chewed during the virtual meal, but the number of bites and chews was lower than in the real meal. The meal duration was reduced from the first virtual meal to the second virtual meal, but no significant difference was observed between the 2 real meals.

CONCLUSIONS

Eating a virtual meal does not appear to significantly reduce hunger in healthy individuals. Also, this methodology does not significantly result in eating behaviors identical to real-life conditions but does evoke chewing and bite behavior in certain individuals.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05734209, https://clinicaltrials.gov/ct2/show/NCT05734209.

The effect of slow-release milk replacer feeding on health and behaviour parameters in dairy breed calves

The aim of this research paper was to evaluate the effect of a slow-release milk replacer on health and behaviour of neonatal dairy calves. This was done with the potential benefits to welfare during transport in mind. A total of 15 calves were randomly divided into three groups of 5, namely, a control group fed twice in 24 h with 3 l of a conventional milk replacer, a slow-release group fed once in 24 h with 2 l of conventional milk replacer and 1 litre of a specialised micro-encapsulated feed and an enriched-replacer group fed once in 24 h with 3 l of milk replacer enriched with micellar casein. Blood samples were taken before feeding and 6, 12, 18 and 24 h after and analysed for acid-base parameters, electrolytes, glucose, haemoglobin, cortisol, insulin, cholecystokinin and adiponectin. Calf behaviour was recorded between 6 and 14 h after feeding. There was a significant increase in blood pH 6 h after feeding in all groups, but the glucose, HCO3 - and base excess increased significantly in the slow-release group only, whereas sodium increased significantly in the enriched group only. Glucose levels remained significantly higher in the slow-release group, relative to the control, at 6, 12, and 18 h after feeding. Insulin levels changed significantly over time in the enriched and control group but remained constant in the slow-release group. Insulin levels were significantly higher in the control group when compared to the slow-release group after feeding. Adiponectin changed significantly over time after feeding in the control group only, but no significant changes were observed between the feeding groups. Behavioural patterns were similar in control and slow release groups but less favourable (less lying time, more vocalisations) in the enriched group. In conclusion, once-daily feeding of slow-release milk replacer demonstrated favourable patterns of blood variables related to satiety and hunger as well as behavioural patterns that did not differ from conventional twice-daily feeding.

A New and Effective Technique in the Endoscopic Treatment of Obesity and Regulation of Diabetes: The Pyloric Revision

AIM

This study aimed to investigate the role of the functional structure of the pylorus in obesity and diabetes and to determine the efficacy of a new method, pyloric revision (PR), in the treatment.

METHODS

The pyloric structures of the patients who applied for endoscopic obesity treatment were examined, and the patients were classified as normotonic (NP), hypotonic (HP), and atonic (AP) according to their pyloric structures. PR was applied to those with pyloric structural disorders. Patients with NP were also given the preferred endoscopic treatment (balloon, botulinum toxin, Kanlioz technique). In addition, the pre-procedure fasting blood glucose (FBG) and glycated hemoglobin levels (HbA1c) of the patients were compared with the sixth-month post-procedure status. In order to compare the pyloric structure and other parameters in normal weights with the obese group, a second group of 100 normal-weight (BMI<25) individuals was formed and compared with the study group.

RESULTS

In patients with HP (93 patients) and AP (61 patients), a statistically significant decrease was found between HbA1c and FBG levels before treatment and six months after treatment (p˂0.02, p<0.001, respectively). There was a statistically significant difference in favor of the endoscopic obesity treatment group (EOTG) in terms of pyloric disorder, HbA1c, and FPG levels between the EOTG and the normal weight group (NWG) (p<0.0001).

CONCLUSION

We recommend using PR as an easy-to-perform, effective, minimally invasive, reproducible, and cost-effective technique that does not require hospitalization.

The effects of wholegrain processing on appetite: randomised crossover trial in adults with type 2 diabetes

Aims: Recent observational data indicate higher ultra-processed food intakes are associated with a broad range of adverse health outcomes. Experimental studies on why this might be are lacking. We have considered the effects of wholegrain processing on measures of appetite in free-living adults with type 2 diabetes. Materials and methods: Participants were randomised to two interventions of two-weeks duration, separated by washout. Interventions were nutrient-matched wholegrain foods that differed by the amount of processing. Self-reported hunger and satiety were indicated on visual analogue scales before or after meals for four days at baseline and the end of each intervention. Metabolite markers of appetite were measured pre and post intervention in fasting plasma. Results: 31 adults (63 ± 13 years old, BMI 32.4 ± 7, HbA1c 7.5 ± 3.4% (59 ± 14 mmol mol-1)) commenced the trial, 28 (90%) completed both interventions. Wholegrain consumption, as measured by alkylresorcinols, was balanced between interventions. Self-reported pre-meal hunger was consistently lower at breakfast (MD, mean difference 0.49/10 95% CI 0.03 to 0.94), lunch (MD 0.67/10 95% CI 0.09 to 1.25), and dinner (MD -0.71/10 95% CI 0.19 to 1.23) during the intervention of less processed whole grains when compared with pre-intervention measures, however this did not result in a difference between interventions. Change in metabolite markers of appetite did not differ between interventions. Conclusions: A significant difference in hunger or satiety between less and more processed whole grains over intervention periods of two weeks was not detected within the current trial. Further experimental studies are needed to consider the potential effects of food processing on physiological processes such as appetite to provide mechanistic understanding behind observations of highly processed food intakes and adverse health outcomes.

Effects of whole seaweed consumption on humans: current evidence from randomized-controlled intervention trials, knowledge gaps, and limitations

Seaweed is often recognized for its potential health benefits, attributed to its abundance of dietary fibers, protein, and polyphenols. While human observational studies have shown promise, the collective evidence from human intervention trials remains limited. This narrative review aims to comprehensively analyze the effects of seaweed intake on humans, while critically assessing the methodology, including Cochrane risk-of-bias assessment. A search was conducted in online databases, including PubMed, Scopus, and Google Scholar, covering the period from 2000 to May 2023. The focus was on randomized controlled clinical trials (RCTs) evaluating the impact of whole seaweed, either consumed as capsules, integrated into food products or as part of meals. Various health outcomes were examined, including appetite, anthropometric measures, cardiometabolic risk factors, thyroid function, markers of oxidative stress, and blood mineral concentrations. Out of the 25 RCTs reviewed, the findings revealed limited yet encouraging evidence for effects of seaweed on blood glucose metabolism, blood pressure, anthropometric measures, and, to a lesser extent, blood lipids. Notably, these favorable effects were predominantly observed in populations with type-2 diabetes and hypertension. Despite most trials selecting a seaweed dose aligning with estimated consumption levels in Japan, considerable variability was observed in the pretreatment and delivery methods of seaweed across studies. Moreover, most studies exhibited a moderate-to-high risk of bias, posing challenges in drawing definitive conclusions. Overall, this review highlights the necessity for well-designed RCTs with transparent reporting of methods and results. Furthermore, there is a need for RCTs to explore seaweed species cultivated outside of Asia, with a specific emphasis on green and red species. Such studies will provide robust evidence-based support for the growing utilization of seaweed as a dietary component in regions with negligible seaweed consumption, e.g., Europe.

Evaluation of Subjective Appetite Assessment under Free-Living vs. Controlled Conditions: A Randomized Crossover Trial Comparing Whole-Grain Rye and Refined Wheat Diets (VASA-Home)

BACKGROUND

Accurate assessment of self-reported appetite under free-living conditions is warranted to conduct large-scale intervention studies measuring appetite at a feasible cost. However, the performance of visual analogue scales (VASs) for this purpose has not been widely examined.

METHOD

This randomized crossover trial was conducted to evaluate VASs in free-living vs. clinic-based settings and to assess appetite response following hypocaloric whole-grain rye and refined wheat diets. Twenty-nine healthy adults with overweight or obesity continuously answered VAS questions about their perceived appetite from morning to evening.

RESULTS

No differences in whole-day VAS scores (primary outcome) between clinic-based and free-living settings were observed, whereas measures of total area under the curve (tAUC) showed increased fullness in clinic-based interventions of 7% (p < 0.008) for whole-day responses and 13% (p < 0.03) following a snack. Appetite responses for a whole day did not differ between diets whereas rye-based dinners induced 12% (p < 0.016) higher fullness and reduced hunger by 17% (p < 0.02) irrespective of setting. A reduction in hunger of 15% (p < 0.05) was also observed following rye-based vs. wheat-based lunches.

CONCLUSION

The results suggest that the VAS is valid for evaluation of appetite responses between diets under free-living conditions. No difference in self-reported appetite over the whole day was found after whole-grain rye vs. refined wheat-based diets, but there were some suggested differences at certain postprandial periods, in individuals with overweight or obesity.

No Evidence That Circulating GLP-1 or PYY Are Associated with Increased Satiety during Low Energy Diet-Induced Weight Loss: Modelling Biomarkers of Appetite

Bariatric surgery and pharmacology treatments increase circulating glucagon-like peptide-1 (GLP-1) and peptide YY (PYY), in turn promoting satiety and body weight (BW) loss. However, the utility of GLP-1 and PYY in predicting appetite response during dietary interventions remains unsubstantiated. This study investigated whether the decrease in hunger observed following low energy diet (LED)-induced weight loss was associated with increased circulating 'satiety peptides', and/or associated changes in glucose, glucoregulatory peptides or amino acids (AAs). In total, 121 women with obesity underwent an 8-week LED intervention, of which 32 completed an appetite assessment via a preload challenge at both Week 0 and Week 8, and are reported here. Visual analogue scales (VAS) were administered to assess appetite-related responses, and blood samples were collected over 210 min post-preload. The area under the curve (AUC_0-210), incremental AUC (iAUC_0-210), and change from Week 0 to Week 8 (∆) were calculated. Multiple linear regression was used to test the association between VAS-appetite responses and blood biomarkers. Mean (±SEM) BW loss was 8.4 ± 0.5 kg (-8%). Unexpectedly, the decrease in ∆AUC_0-210 hunger was best associated with decreased ∆AUC_0-210 GLP-1, GIP, and valine (p < 0.05, all), and increased ∆AUC_0-210 glycine and proline (p < 0.05, both). The majority of associations remained significant after adjusting for BW and fat-free mass loss. There was no evidence that changes in circulating GLP-1 or PYY were predictive of changes in appetite-related responses. The modelling suggested that other putative blood biomarkers of appetite, such as AAs, should be further investigated in future larger longitudinal dietary studies.

Enhanced secretion of satiety-promoting gut hormones in healthy humans after consumption of white bread enriched with cellular chickpea flour: A randomized crossover study

BACKGROUND

Dietary intake of pulses is associated with beneficial effects on body weight management and cardiometabolic health, but some of these effects are now known to depend on integrity of plant cells, which are usually disrupted by flour milling. Novel cellular flours preserve the intrinsic dietary fiber structure of whole pulses and provide a way to enrich preprocessed foods with encapsulated macronutrients.

OBJECTIVES

This study aimed to determine the effects of replacing wheat flour with cellular chickpea flour on postprandial gut hormones, glucose, insulin, and satiety responses to white bread.

METHODS

We conducted a double-blind randomized crossover study in which postprandial blood samples and scores were collected from healthy human participants (n = 20) after they consumed bread enriched with 0%, 30%, or 60% (wt/wt) cellular chickpea powder (CCP, 50 g total starch per serving).

RESULTS

Bread type significantly affected postprandial glucagon-like peptide-1 (GLP-1) and peptide YY (PYY) responses (time × treatment, P = 0.001 for both). The 60% CCP breads elicited significantly elevated and sustained release of these anorexigenic hormones [between 0% and 60% CPP-GLP-1: mean difference incremental area under the curve (iAUC), 3101 pM/min; 95% CI: 1891, 4310; P-adjusted < 0.001; PYY: mean difference iAUC, 3576 pM/min; 95% CI: 1024, 6128; P-adjusted = 0.006] and tended to increase fullness (time × treatment, P = 0.053). Moreover, bread type significantly influenced glycemia and insulinemia (time × treatment, P < 0.001, P = 0.006, and P = 0.001 for glucose, insulin, and C-peptide, respectively), with 30% CCP breads eliciting a >40% lower glucose iAUC (P-adjusted < 0.001) than the 0% CCP bread. Our in vitro studies revealed slow digestion of intact chickpea cells and provide a mechanistic explanation for the physiologic effects.

CONCLUSIONS

The novel use of intact chickpea cells to replace refined flours in a white bread stimulates an anorexigenic gut hormone response and has potential to improve dietary strategies for prevention and treatment of cardiometabolic diseases. This study was registered at clinicaltrials.gov as NCT03994276.

Nuts, Energy Balance and Body Weight

Over several decades, the health benefits of consuming nuts have been investigated, resulting in a large body of evidence that nuts can reduce the risk of chronic diseases. The consumption of nuts, being a higher-fat plant food, is restricted by some in order to minimize weight gain. In this review, we discuss several factors related to energy intake from nuts, including food matrix and its impact on digestibility, and the role of nuts in regulating appetite. We review the data from randomized controlled trials and observational studies conducted to examine the relationship between nut intake and body weight or body mass index. Consistently, the evidence from RCTs and observational cohorts indicates that higher nut consumption does not cause greater weight gain; rather, nuts may be beneficial for weight control and prevention of long-term weight gain. Multiple mechanisms likely contribute to these findings, including aspects of nut composition which affect nutrient and energy availability as well as satiety signaling.

Efficacy, feasibility and tolerability of ketogenic diet for the treatment of poor response to bariatric surgery

PURPOSE

Poor response to bariatric surgery, namely insufficient weight loss (IWL) or weight regain (WR), is a critical issue in the treatment of obesity. The purpose of our study was to assess the efficacy, feasibility, and tolerability of very low-calorie ketogenic diet (VLCKD) for the management of this condition.

METHODS

A real-life prospective study was conducted on twenty-two patients who experienced poor response after bariatric surgery and followed a structured VLCKD. Anthropometric parameters, body composition, muscular strength, biochemical analyses, and nutritional behavior questionnaires were evaluated.

RESULTS

A significant weight loss (mean 14.1 ± 4.8%), mostly due to fat mass, was observed during VLCKD with the preservation of muscular strength. The weight loss obtained allowed patients with IWL to reach a body weight significantly lower than that obtained at the post-bariatric surgery nadir and to report the body weight of patients with WR at the nadir observed after surgery. The significantly beneficial changes in nutritional behaviors and metabolic profiles were observed without variations in kidney and liver function, vitamins, and iron status. The nutritional regimen was well tolerated, and no significant side effects were detected.

CONCLUSION

Our data demonstrate the efficacy, feasibility, and tolerability of VLCKD in patients with poor response after bariatric surgery.

Children's eating behaviours and related constructs: conceptual and theoretical foundations and their implications

BACKGROUND

There is a substantial body of research on children's eating behaviours (e.g., food responsiveness and fussiness) and related constructs (e.g., eating in the absence of hunger, appetite self-regulation). This research provides a foundation for understanding children's dietary intakes and healthy eating behaviours, as well as efforts at intervention, whether in relation to food avoidance, overeating and/or trajectories to excess weight gain. The success of these efforts and their associated outcomes is dependent on the theoretical foundation and conceptual clarity of the behaviours and constructs. This, in turn contributes to the coherence and precision of the definitions and measurement of these behaviours and constructs. Limited clarity in these areas ultimately creates uncertainty around the interpretation of findings from research studies and intervention programs. At present there does not appear to be an overarching theoretical framework of children's eating behaviours and associated constructs, or for separate domains of children's eating behaviours/constructs. The main purpose of the present review was to examine the possible theoretical foundations of some of the main current questionnaire and behavioural measures of children's eating behaviours and related constructs.

METHODS

We reviewed the literature on the most prominent measures of children's eating behaviours for use with children aged ~ 0-12 years. We focused on the explanations and justifications for the original design of the measures and whether these included theoretical perspectives, as well as current theoretical interpretations (and difficulties) of the behaviours and constructs.

RESULTS

We found that the most commonly used measures had their foundations in relatively applied or practical concerns rather than theoretical perspectives.

CONCLUSIONS

We concluded, consistent with Lumeng & Fisher (1), that although existing measures have served the field well, to advance the field as a science, and better contribute to knowledge development, increased attention should be directed to the conceptual and theoretical foundations of children's eating behaviours and related constructs. Suggestions for future directions are outlined.

Gastrointestinal hormones and appetite ratings after weight loss induced by diet or bariatric surgery

OBJECTIVE

The aim of this study was to compare changes in gastrointestinal hormones and appetite ratings after a similar weight loss induced by a very low-energy diet alone or in combination with sleeve gastrectomy (SG) or Roux-en-Y gastric bypass (RYGB).

METHODS

Patients with severe obesity scheduled for SG (n = 15) and RYGB (n = 14) and 15 controls (very low-energy diet alone) were recruited. Body weight/composition, plasma concentrations of ß-hydroxybutyric acid, acylated ghrelin, total glucagon-like peptide-1, total peptide YY, cholecystokinin, and ratings of hunger, fullness, desire to eat, and prospective food consumption were measured pre- and postprandially, before and after 10 weeks of intervention.

RESULTS

Changes in body weight/composition and level of ketosis were similar across groups. In SG and RYGB, basal and postprandial acylated ghrelin declined, and postprandial glucagon-like peptide-1 increased, both significantly more compared with controls. Postprandial peptide YY increased in all groups. Overall, postprandial hunger decreased, and postprandial fullness increased. But ratings of desire to eat and prospective food consumption were more favorable after both surgeries compared with controls.

CONCLUSIONS

Weight loss with SG and RYGB leads to more favorable changes in gastrointestinal hormones compared with diet alone, although ratings of appetite were reduced across all groups.

Acute feeding with almonds compared to a carbohydrate-based snack improves appetite-regulating hormones with no effect on self-reported appetite sensations: a randomised controlled trial

PURPOSE

Early satiety has been identified as one of the mechanisms that may explain the beneficial effects of nuts for reducing obesity. This study compared postprandial changes in appetite-regulating hormones and self-reported appetite ratings after consuming almonds (AL, 15% of energy requirement) or an isocaloric carbohydrate-rich snack bar (SB).

METHODS

This is a sub-analysis of baseline assessments of a larger parallel-arm randomised controlled trial in overweight and obese (Body Mass Index 27.5-34.9 kg/m²) adults (25-65 years). After an overnight fast, 140 participants consumed a randomly allocated snack (AL [n = 68] or SB [n = 72]). Appetite-regulating hormones and self-reported appetite sensations, measured using visual analogue scales, were assessed immediately before snack food consumption, and at 30, 60, 90 and 120 min following snack consumption. A sub-set of participants (AL, n = 49; SB, n = 48) then consumed a meal challenge buffet ad libitum to assess subsequent energy intake. An additional appetite rating assessment was administered post buffet at 150 min.

RESULTS

Postprandial C-peptide area under the curve (AUC) response was 47% smaller with AL compared to SB (p < 0.001). Glucose-dependent insulinotropic polypeptide, glucagon and pancreatic polypeptide AUC responses were larger with AL compared to SB (18%, p = 0.005; 39% p < 0.001; 45% p < 0.001 respectively). Cholecystokinin, ghrelin, glucagon-like peptide-1, leptin and polypeptide YY AUCs were not different between groups. Self-reported appetite ratings and energy intake following the buffet did not differ between groups.

CONCLUSION

More favourable appetite-regulating hormone responses to AL did not translate into better self-reported appetite or reduced short-term energy consumption. Future studies should investigate implications for longer term appetite regulation.

ANZCTR REFERENCE NUMBER

ACTRN12618001861246 2018.

The Restrain Food Database: validation of an open-source database of foods that should be eaten more or less as part of a healthy diet

Studies of food-related behaviours often involve measuring responses to pictorial stimuli of foods. Creating these can be burdensome, requiring a significant commitment of time, and with sharing of images for future research constrained by legal copyright restrictions. The Restrain Food Database is an open-source database of 626 images of foods that are categorized as those people could eat more or less of as part of a healthy diet. This paper describes the database and details how to navigate it using our purpose-built R Shiny tool and a pre-registered online validation of a sample of images. A total of 2150 participants provided appetitive ratings, perceptions of nutritional content and ratings of image quality for images from the database. We found support for differences between Food Category on appetitive ratings which were also moderated by state hunger ratings. Findings relating to individual differences in appetite ratings as well as differences between BMI weight categories are also reported. Our findings validate the food categorization in the Restrain Food Database and provide descriptive information for individual images within this investigation. This database should ease the burden of selecting and creating appropriate images for future studies.

Alternate day fasting on subjective feelings of appetite and body weight for adults with overweight or obesity: a systematic review

Alternate day fasting (ADF) with consumption of calories up to 25 % of the daily energy intake on fast days is one of the most used intermittent fasting regimens and promoted as a promising, alternative approach for treating obesity. Feelings of appetite are critical for adherence to dietary approaches, and therefore the success of dietary interventions. This systematic review aimed to assess the effects of a minimum of 8 weeks of ADF on subjective feelings of appetite and body weight for adults with overweight and obesity. We conducted the review in accordance with the Cochrane guidelines, including systematic searches in four databases. Because of the high level of clinical and methodological heterogeneity, a narrative approach was used to synthesise the results. Eight studies with a total of 456 participants met the eligibility criteria: three randomised controlled trials and five uncontrolled before-after studies. Seven of the studies had high risk of bias. Feelings of appetite were assessed by hunger in eight studies, fullness in seven studies, satisfaction in four studies and desire to eat in one study. All the studies assessed weight loss. The certainty of the evidence was rated low or very low for all outcomes, thus no firm conclusions can be drawn about the potential benefits of ADF on subjective feelings of appetite and body weight. Despite the high interest in ADF, good quality evidence is still needed to determine its effectiveness and if offered in clinical practice, ADF should be offered cautiously while concomitantly evaluated.

Holistic approach to effects of foods, human physiology, and psychology on food intake and appetite (satiation & satiety)

Appetite (satiation and satiety) is an essential element for the control of eating behavior, and as a consequence human nutrition, body weight, and chronic disease risk. A better understanding of appetite mechanisms is necessary to modulate eating behavior and food intake, and also provide a practical approach for weight management. Although many researchers have investigated the relationships between satiation/satiety and specific factors including human physiology, psychology, and food characteristics, limited information on the interactions between factors or comparisons between the relative importance of factors in contributing to satiation/satiety have been reported. This article reviews progress and gaps in understanding individual attributes contributing to perceived satiation/satiety, the advantages of considering multiple factors together in appetite experiments, as well as the applications of nondestructive sensing in evaluating human factors contributing to relative appetite perception. The approaches proposed position characterization of appetite (satiation and satiety) for personalized and precision nutrition in relation to human status and healthy diets. In particular, it is recommended that future studies of appetite perception recognize the inter-dependence of food type and intake, appetite (satiation and satiety), and individual status.

Short-Term Effect of Additional Daily Dietary Fibre Intake on Appetite, Satiety, Gastrointestinal Comfort, Acceptability, and Feasibility

Background: There is evidence that high-fibre diets have significant health benefits, although the effect of increasing fibre on individuals’ appetite, satiety, and gastrointestinal comfort is not well established, nor is its acceptability and feasibility. Methods: This mixed-methods feasibility randomised control trial included 38 participants allocated to one of three conditions: FibreMAX (two daily servings of 25 g of BARLEYmax^®), FibreGRAD (two daily servings with the amount of fibre gradually increased), and Control (two daily servings totalling 25 g of placebo product). Participants completed a food diary at baseline. The Hunger and Fullness Questionnaire and questions regarding gastrointestinal response were completed at baseline and at the end of each week. Participants completed the acceptability of intervention measure and engaged in a semi-structured interview, following trial completion. Results: The qualitative data suggested that increased fibre influenced appetite and fullness perceptions. Baseline fibre consumption and the method of increased fibre increase did not influence our findings. The qualitative results also indicated that the fibre intake was perceived as beneficial to well-being; it influenced feelings of hunger and caused some minor acute gastrointestinal symptoms that dissipated after a short adaption period. Conclusion: This study suggests that increasing fibre intake through BARLEYmax^® is a safe intervention that is acceptable to participants.

The promise of new anti-obesity therapies arising from knowledge of genetic obesity traits

Obesity is a multifactorial and complex disease that often manifests in early childhood with a lifelong burden. Polygenic and monogenic obesity are driven by the interaction between genetic predisposition and environmental factors. Polygenic variants are frequent and confer small effect sizes. Rare monogenic obesity syndromes are caused by defined pathogenic variants in single genes with large effect sizes. Most of these genes are involved in the central nervous regulation of body weight; for example, genes of the leptin-melanocortin pathway. Clinically, patients with monogenic obesity present with impaired satiety, hyperphagia and pronounced food-seeking behaviour in early childhood, which leads to severe early-onset obesity. With the advent of novel pharmacological treatment options emerging for monogenic obesity syndromes that target the central melanocortin pathway, genetic testing is recommended for patients with rapid weight gain in infancy and additional clinical suggestive features. Likewise, patients with obesity associated with hypothalamic damage or other forms of syndromic obesity involving energy regulatory circuits could benefit from these novel pharmacological treatment options. Early identification of patients affected by syndromic obesity will lead to appropriate treatment, thereby preventing the development of obesity sequelae, avoiding failure of conservative treatment approaches and alleviating stigmatization of patients and their families.

Insights into the constellating drivers of satiety impacting dietary patterns and lifestyle

Food intake and body weight regulation are of special interest for meeting today's lifestyle essential requirements. Since balanced energy intake and expenditure are crucial for healthy living, high levels of energy intake are associated with obesity. Hence, regulation of energy intake occurs through short- and long-term signals as complex central and peripheral physiological signals control food intake. This work aims to explore and compile the main factors influencing satiating efficiency of foods by updating recent knowledge to point out new perspectives on the potential drivers of satiety interfering with food intake regulation. Human internal factors such as genetics, gender, age, nutritional status, gastrointestinal satiety signals, gut enzymes, gastric emptying rate, gut microbiota, individual behavioral response to foods, sleep and circadian rhythms are likely to be important in determining satiety. Besides, the external factors (environmental and behavioral) impacting satiety efficiency are highlighted. Based on mechanisms related to food consumption and dietary patterns several physical, physiological, and psychological factors affect satiety or satiation. A complex network of endocrine and neuroendocrine mechanisms controls the satiety pathways. In response to food intake and other behavioral cues, gut signals enable endocrine systems to target the brain. Intestinal and gastric signals interact with neural pathways in the central nervous system to halt eating or induce satiety. Moreover, complex food composition and structures result in considerable variation in satiety responses for different food groups. A better understanding of foods and factors impacting the efficiency of satiety could be helpful in making smart food choices and dietary recommendations for a healthy lifestyle based on updated scientific evidence.

Association and interaction of the MC4R rs17782313 polymorphism with plasma ghrelin, GLP-1, cortisol, food intake and eating behaviors in overweight/obese Iranian adults

BACKGROUND

Recent studies have shown that obesity is largely influenced by heredity and created by the interactions between several genes and environmental and behavioral factors. This study aimed to examine association between variant rs17782313 near melanocortin-4 receptor (MC4R) gene and behavioral and hormonal factors then evaluated interactions between variant MC4R rs17782313 with behavioral and hormonal factors on obesity.

METHODS

This cross-sectional study included 403 subjects, overweight and/or obesity, aged 20-50 years from Iran. The MC4R rs17782313 data were measured by the PCR-RFLP method. Dietary intake, physical activity, stress, anxiety, depression, appetite and emotional eating were assessed by using validated questionnaires. Ghrelin, glucagon-like peptide-1 and cortisol were measured by radioimmunoassay in plasma samples. Participants were also divided into three groups based on rs17782313 genotype and BMI.

RESULTS

After adjustment for age, gender, energy intake and PA, significant associations were observed between food intake, appetite, emotional eating, stress and physical activity with MC4R rs17782313 (p ˂0.05). Also, significant interactions were observed between fat intake (p-interaction = 0.002), protein intake (p-interaction = 0.01), energy intake (p-interaction = 0.01), emotional eating (p-interaction = 0.02), appetite (p-interaction = 0.04), stress (p-interaction = 0.04), ghrelin (p-interaction = 0.03), cortisol (p-interaction = 0.04) and physical activity (p-interaction = 0.04) and MC4R rs17782313 in terms of BMI.

CONCLUSION

Interactions between the CC genotype and high intakes of fat and energy, emotional eating, high appetite, and too much stress with high levels of cortisol and ghrelin probably can have an effect on BMI in overweight/obese subjects.

Measuring hyperphagia in patients with monogenic and syndromic obesity

BACKGROUND

Hyperphagia is a key symptom in patients with monogenic obesity, but the assessment is challenging.

OBJECTIVES

We aimed to investigate the applicability of Dykens' Hyperphagia Questionnaire in patients with monogenic and syndromic obesity to assess the quality and severity of hyperphagia, and to compare our results with those reported in the literature.

METHODS

Patients with biallelic leptin receptor variants (LEPR, n = 8), heterozygous melanocortin-4 receptor variants (MC4R, n = 7) and 16p11.2 deletions, leading to a deletion of the Src homology 2B adaptor protein gene (n = 5) were included in the study. Hyperphagia was assessed by the parent-based, 13-item hyperphagia questionnaire from Dykens et al. (2007). A literature research was performed to identify published hyperphagia scores assessed by Dykens' Hyperphagia Questionnaire.

RESULTS

The total hyperphagia scores were similar in patients with biallelic LEPR and monoallelic MC4R variants (32.0 ± 9.3 vs. 31.4 ± 5.4), but significantly lower in patients with 16p11.2 deletions (21.4 ± 5.5, p < 0.05). Compared to patients with syndromic obesity (27.6 ± 9.0) from the literature, patients with LEPR and MC4R variants had higher total hyperphagia scores. Total hyperphagia scores in patients with 16p11.2 deletions were lower than for patients with other syndromic obesity forms (21.4 ± 5.5 vs. 24.6 ± 8.1), but similar to those for individuals with obesity without a genetic cause (22.9 ± 7.2).

CONCLUSIONS

Dykens' Hyperphagia Questionnaire seems to be a useful tool to assess hyperphagic behaviour in patients with monogenic and syndromic obesity.

The impact of 16-h heat exposure on appetite and food reward in adults

Heat exposure is thought to reduce energy intake (EI) but studies are sparse and results not always concordant. The aim of this study was to examine whether a 16-h exposure to 32 °C leads to reduced EI compared to a control session (22 °C) and whether modifications in appetite sensations or food reward are implied. Sixteen healthy, lean, and active participants (9 women and 7 men, 25 ± 5 yo, body mass index: 22.0 ± 2.4 kg.m^-2) were passively exposed to two different thermal temperatures from 4:00 pm to 8:00 am under controlled conditions. Hunger and thirst scores were regularly assessed using visual analogue scales. A fixed dinner meal (3670 ± 255 kJ) was consumed at 7:30 pm and an ad libitum breakfast buffet (20 foods/drinks varying in temperature, fat, and carbohydrate content) at 7:30 am. Components of reward (explicit liking [EL] and implicit wanting [EI]) for fat and sweet properties of food were assessed before each meal using the Leeds Food Preference Questionnaire (LFPQ). Ad libitum EI at breakfast did not differ between sessions (2319 ± 1108 vs 2329 ± 1141 kJ, in 22 and 32 °C sessions, respectively; p = 0.955). While thirst scores were higher in the 32 than the 22 °C session (p < 0.001), hunger scores did not differ (p = 0.580). EL and IW for high fat foods relative to low fat foods were decreased in 32 compared to 22 °C before dinner and breakfast (p < 0.001 for all). Although EI and hunger were not affected by a 16-h exposure to heat, modifications in food reward suggested a reduction in the preference of high-fat foods. Future research should investigate whether reduced EI in response to heat exposure is due to spontaneous selection of low-fat foods rather than altered appetite sensations.

Association between CLOCK 3111 T/C polymorphism with ghrelin, GLP-1, food timing, sleep and chronotype in overweight and obese Iranian adults

BACKGROUND

Circadian Locomotor Output Cycles Kaput (CLOCK), an essential element of the positive regulatory arm in the human biological clock, is involved in metabolic regulation. The aim was to investigate the behavioral (sleep duration, food timing, dietary intake, appetite and chronobiologic characteristics) and hormonal (plasma ghrelin and Glucagon-like peptide-1 concentrations) factors that could explain the previously reported association between the CLOCK 3111 T/C SNP and obesity.

METHODS

This cross-sectional study included 403 subjects, overweight and/or obesity, aged 20- 50 years from Iran. The CLOCK rs1801260 data were measured by the PCR-RFLP method. Dietary intake, food timing, sleep duration, appetite and Chrono-type were assessed using validated questionnaires. Ghrelin and GLP-1 were measured by ELIZA in plasma samples. Participants were also divided into three groups based on BMI. Logistic regression models and general linear regression models were used to assess the association between CLOCK genotype and study parameters. Univariate linear regression models were used to assess the interaction between CLOCK and VAS, Food timing, chronotype and sleep on food intakes.

RESULTS

After controlling for confounding factors, there was a significant difference between genotypes for physical activity (P = 0.001), waist circumference (P˂0.05), BMI (˂0.01), weight (P = 0.001), GLP-1 (P = 0.02), ghrelin (P = 0.04), appetite (P˂0.001), chronotype (P˂0.001), sleep (P˂0.001), food timing (P˂0.001), energy (P˂0.05), carbohydrate (P˂0.05) and fat intake (P˂0.001). Our findings also show that people with the minor allele C who ate lunch after 3 PM and breakfast after 9 AM are more prone to obesity (P˂0.05). furthermore, there was significant interactions between C allele carrier group and high appetite on fat intake (Pinteraction = 0.041), eat lunch after 3 PM on energy intake (Pinteraction = 0.039) and morning type on fat intake (Pinteraction = 0.021).

CONCLUSION

Sleep reduction, changes in ghrelin and GLP-1 levels, changes in eating behaviors and evening preference that characterized CLOCK 3111C can all contribute to obesity. Furthermore, the data demonstrate a clear relationship between the timing of food intake and obesity. Our results support the hypothesis that the influence of the CLOCK gene may extend to a wide range of variables related to human behaviors.

Integrating Effects of Human Physiology, Psychology, and Individual Variations on Satiety–An Exploratory Study

Satiety can influence food intake, and as a consequence has the potential to affect weight and obesity. Human factors such as physiology and psychology are likely to be important in determining satiety. However, it is not well-understood how these factors (individual variations) alone or combined contribute to satiety feelings. In addition, there have been limited or no attempts to use a holistic approach to evaluate satiety. In this study, three plant-based foods were used as mid-morning snack for 52 participants to evaluate satiety response (during three consecutive days, one-day-one-food type). The foods were served ad libitum until participants felt comfortably full prior to satiety monitoring. The study explored diverse human factors (n = 30) that might contribute to satiety including those related to oral physiology, metabolic factors, body composition and psychology. It identified important variables for satiety as well as the interactions among them and the influences of age, gender, and low satiety phenotype (consistently lower reported fullness scores) on satiety. Overall, combinations of factors rather than individual ones contributed to self-reported satiety. Food factors (e.g., type, composition) had limited effects, but there were only three types used in the study. The combination of metabolic factors [respiratory quotient, age, and body energy usage type (e.g., carbohydrate or fat)], oral sensitivity & processing, personality traits (agreeableness, conscientiousness, and neuroticism), and eating behavior (e.g., emotional and external eating) were the most important for explaining individual satiety responses. Older participants had significantly higher reported satiety than younger participants, associated with significant differences in oral physiology, increased body fat, and mature psychological characters. Moreover, different satiety phenotypes had significant differences in relationships with body fat, oral physiology, personalities, food neophobia, and eating behaviors. The results of this study indicate that much greater insights into the factors determining satiety responses can be obtained by combining multiple food and human physiological and psychological characteristics. This study used more diverse measures of individual variation than previous studies of satiety and points the way toward a more holistic approach to understanding the (control of) perceptions of fullness at both individual and group levels.

Predicting Satiety from the Analysis of Human Saliva Using Mid-Infrared Spectroscopy Combined with Chemometrics

The aim of this study was to evaluate the ability of mid-infrared (MIR) spectroscopy combined with chemometrics to analyze unstimulated saliva as a method to predict satiety in healthy participants. This study also evaluated features in saliva that were related to individual perceptions of human–food interactions. The coefficient of determination (R²) and standard error in cross validation (SECV) for the prediction of satiety in all saliva samples were 0.62 and 225.7 satiety area under the curve (AUC), respectively. A correlation between saliva and satiety was found, however, the quantitative prediction of satiety using unstimulated saliva was not robust. Differences in the MIR spectra of saliva between low and high satiety groups, were observed in the following frequency ratios: 1542/2060 cm⁻¹ (total protein), 1637/3097 cm⁻¹ (α-amino acids), and 1637/616 (chlorides) cm⁻¹. In addition, good to excellent models were obtained for the prediction of satiety groups defined as low or high satiety participants (R² 0.92 and SECV 0.10), demonstrating that this method could be used to identify low or high satiety perception types and to select participants for appetite studies. Although quantitative PLS calibration models were not achieved, a qualitative model for the prediction of low and high satiety perception types was obtained using PLS-DA. Furthermore, this study showed that it might be possible to evaluate human/food interactions using MIR spectroscopy as a rapid and cost-effective tool.

Dysbiotic Gut Bacteria in Obesity: An Overview of the Metabolic Mechanisms and Therapeutic Perspectives of Next-Generation Probiotics

Obesity, a worldwide health concern with a constantly rising prevalence, is a multifactorial chronic disease associated with a wide range of physiological disruptions, including energy imbalance, central appetite and food reward dysregulation, and hormonal alterations and gut dysbiosis. The gut microbiome is a well-recognized factor in the pathophysiology of obesity, and its influence on host physiology has been extensively investigated over the last decade. This review highlights the mechanisms by which gut dysbiosis can contribute to the pathophysiology of obesity. In particular, we discuss gut microbiota’s contribution to host energy homeostatic changes, low-grade inflammation, and regulation of fat deposition and bile acid metabolism via bacterial metabolites, such as short-chain fatty acids, and bacterial components, such as lipopolysaccharides, among others. Finally, therapeutic strategies based on next-generation probiotics aiming to re-shape the intestinal microbiota and reverse metabolic alterations associated with obesity are described.

Homeostatic regulation of food intake

Food intake and energy expenditure are key regulators of body weight. To regulate food intake, the brain must integrate physiological signals and hedonic cues. The brain plays an essential role in modulating the appropriate responses to the continuous update of the body energy-status by the peripheral signals and the neuronal pathways that generate the gut-brain axis. This regulation encompasses various steps involved in food consumption, include satiation, satiety, and hunger. It is important to have a comprehensive understanding of the mechanisms that regulate food consumption as well as to standardize the vocabulary for the steps involved. This review discusses the current knowledge of the regulation and the contribution peripheral and central signals at each step of the cycle to control appetite. We also highlight how food intake has been measured. The increasingly complex understanding of regulation and action mechanisms intervening in the gut-brain axis offers ambitious targets for new strategies to control appetite.

Does a Higher Protein Diet Promote Satiety and Weight Loss Independent of Carbohydrate Content? An 8-Week Low-Energy Diet (LED) Intervention

Both higher protein (HP) and lower carbohydrate (LC) diets may promote satiety and enhance body weight (BW) loss. This study investigated whether HP can promote these outcomes independent of carbohydrate (CHO) content. 121 women with obesity (BW: 95.1 ± 13.0 kg, BMI: 35.4 ± 3.9 kg/m2) were randomised to either HP (1.2 g/kg BW) or normal protein (NP, 0.8 g/kg BW) diets, in combination with either LC (28 en%) or normal CHO (NC, 40 en%) diets. A low-energy diet partial diet replacement (LEDpdr) regime was used for 8 weeks, where participants consumed fixed-energy meal replacements plus one ad libitum meal daily. Four-day dietary records showed that daily energy intake (EI) was similar between groups (p = 0.744), but the difference in protein and CHO between groups was lower than expected. Following multiple imputation (completion rate 77%), decrease in mean BW, fat mass (FM) and fat-free mass (FFM) at Week 8 in all was 7.5 ± 0.7 kg (p < 0.001), 5.7 ± 0.5 kg (p < 0.001), and 1.4 ± 0.7 kg (p = 0.054) respectively, but with no significant difference between diet groups. LC (CHO×Week, p < 0.05), but not HP, significantly promoted postprandial satiety during a preload challenge. Improvements in blood biomarkers were unrelated to LEDpdr macronutrient composition. In conclusion, HP did not promote satiety and BW loss compared to NP LEDpdr, irrespective of CHO content.

Intermittent fasting & performance: The iFast clinical trial protocol

There is increasing evidence from animal and human studies suggesting that fasting can play a role in disease prevention, weight control and longevity. However, few studies have compared exercise performances in individuals adhering to an intermittent fasting (IF) in comparison to individuals who are not. Given the rising popularity of IF we aim to investigate whether this type eating pattern will improve cardiovascular performance over a period of 12 weeks through VO₂ max measurements in participants from a Lebanese community. Additionally, we will study the variation of different health parameters, physical performance and biomarkers potentially affected by IF. Participants will be recruited from a large university community and randomized into 4 arms. Baseline information will be collected from all participants, which includes biological, physical, nutritional, medical and psychological data. Two arms will follow a time-restricted fasting diet with and without physical exercise, one arm will exercise without fasting, and one will act as a control group. Throughout the study, measurements will be repeated, and data analysis will follow to evaluate results.

Typology of eating episodes in children and adolescents with overweight/obesity

BACKGROUND

Research suggests that youth with overweight/obesity can be subtyped according to disinhibited eating tendencies. No research has attempted to subtype classes of eating episodes along sensational, psychological, and hedonic dimensions.

METHODS

Youth (N = 39; 55% female) aged 8-14 y with overweight/obesity completed a 2-week ecological momentary assessment protocol in which they reported on all eating episodes and their sensational, environmental, affective, and interpersonal contexts. Latent profile analysis (LPA) was used to classify episodes based on loss of control (LOC) while eating, self-reported overeating, food palatability, hunger, and cravings. Classes were compared on affective, interpersonal, appearance-related, and environmental correlates using Wald chi-square tests.

RESULTS

LPA identified three classes of eating episodes involving high levels of LOC/self-reported overeating ("binge-like" class), low levels of hunger ("eating-in-the-absence-of-hunger" class), and high hunger and cravings ("appetitive eating" class). Binge-like eating was associated with the highest levels of body dissatisfaction, interpersonal distress, and positive affect, and was most likely to occur in the after-school hours.

CONCLUSIONS

Binge-like eating tends to occur in a psychological context relative to other types of eating episodes in youth with overweight/obesity. Future research should explore whether certain classes of eating episodes are associated with distinct weight trajectories over time.

Uncontrolled eating in healthy women has limited influence on food cue reactivity and food-related inhibitory control

Uncontrolled eating-in the general population-is characterized by overeating, hedonic hunger and being drawn towards palatable foods. Theoretically, it is the result of a strong food reward signal in relation to a poor ability to exert inhibitory control. How food consumption influences inhibitory control and food cue sensitivity, and how this relates to the continued urge to eat, remains unclear. We used fMRI in order to investigate the neural mechanism underlying food cue reactivity and food-specific response inhibition (go-nogo task), by comparing women reporting high (n = 21) versus low/average (n = 19) uncontrolled eating across two sessions: during an inter-meal state and after consumption of a high-caloric snack. We found no effects of individual differences in uncontrolled eating, food consumption, nor their interaction on food cue reactivity. Differences in uncontrolled eating and food consumption did interact in modulating activity in an occipital-parietal network, extending from left lateral superior occipital cortex to visual cortex, cuneal cortex, and precuneus during response inhibition of non-food stimuli, areas previously associated with successful nogo-vs. go-trials. Yet, behavioural performance on the go-nogo task was not modulated by uncontrolled eating nor food consumption. Women with a low/average tendency for uncontrolled eating may need more cognitive resources to support successful response inhibition of non-food stimuli during food 'go' blocks in an inter-meal state, whereas women with a high tendency for uncontrolled eating showed this after food consumption. However, considering current and previous findings, it seems that individual differences in uncontrolled eating in healthy women have only limited influence on food cue reactivity and food-related inhibitory control.

Conceptualizing and Measuring Appetite Self-Regulation Phenotypes and Trajectories in Childhood: A Review of Person-Centered Strategies

This review uses person-centered research and data analysis strategies to discuss the conceptualization and measurement of appetite self-regulation (ASR) phenotypes and trajectories in childhood (from infancy to about ages 6 or 7 years). Research that is person-centered provides strategies that increase the possibilities for investigating ASR phenotypes. We first examine the utility of examining underlying phenotypes using latent profile/class analysis drawing on cross-sectional data. The use of trajectory analysis to investigate developmental change is then discussed, with attention to phenotypes using trajectories of individual behaviors as well as phenotypes based on multi-trajectory modeling. Data analysis strategies and measurement approaches from recent examples of these person-centered approaches to the conceptualization and investigation of appetite self-regulation and its development in childhood are examined. Where relevant, examples from older children as well as developmental, clinical and educational psychology are drawn on to discuss when and how person-centered approaches can be used. We argue that there is scope to incorporate recent advances in biological and psychoneurological knowledge about appetite self-regulation as well as fundamental processes in the development of general self-regulation to enhance the examination of phenotypes and their trajectories across childhood (and beyond). The discussion and conclusion suggest directions for future research and highlight the potential of person-centered approaches to progress knowledge about the development of appetite self-regulation in childhood.

Postprandial glycine as a biomarker of satiety: A dose-rising randomised control trial of whey protein in overweight women

This study aimed to identify biomarkers of appetite response, modelled using a dose-rising whey protein preload intervention. Female participants (n = 24) with body mass index (BMI) between 23 and 40 kg/m² consumed preload beverages (0 g protein water control, WC; 12.5 g low-dose protein, LP; or 50.0 g high-dose protein, HP) after an overnight fast, in a randomised cross over design. Repeated venous blood samples were collected to measure plasma biomarkers of appetite response, including glucose, glucoregulatory peptides, gut peptides, and amino acids (AAs). Appetite was assessed using Visual Analogue Scales (VAS) and ad libitum energy intake (EI). Dose-rising protein beverage significantly changed the postprandial trajectory of almost all biomarkers (treatment*time, p < 0.05), but did not suppress postprandial appetite (treatment*time, p > 0.05) or EI (ANOVA, p = 0.799). Circulating glycine had the strongest association with appetite response. Higher area under the curve (AUC_0-240) glycine was associated with lower EI (p = 0.026, trend). Furthermore, circulating glycine was associated with decreased Hunger in all treatment groups, whereas the associations of glucose, alanine and amylin with appetite were dependent on treatment groups. Multivariate models, incorporating multiple biomarkers, improved the estimation of appetite response (marginal R², range: 0.13-0.43). In conclusion, whilst glycine, both alone and within a multivariate model, can estimate appetite response to both water and whey protein beverage consumption, a large proportion of variance in appetite response remains unexplained. Most biomarkers, when assessed in isolation, are poor predictors of appetite response, and likely of utility only in combination with VAS and EI.

Effects of menstrual cycle on appetite-regulating hormones and energy intake in response to cycling exercise in physically active women

Although ample evidence supports the notion that an acute bout of endurance exercise performed at or greater than 70% of maximum oxygen uptake suppresses appetite partly through changes in appetite-regulating hormones, no study has directly compared the influence between the phases of the menstrual cycle in women. The present study compared the effects of an acute bout of exercise on orexigenic hormone (acylated ghrelin) and anorexigenic hormones (peptide YY and cholecystokinin) between the early follicular phase (FP) and the mid luteal phase (LP) of the menstrual cycle in physically active women. Ten healthy women (age, 20.6 ± 0.7 years) completed two 3.5-h trials in each menstrual phase. In both trials, participants performed cycling exercises at 70% of heart rate reserve (at a corresponding intensity to 70% of maximum oxygen uptake) for 60 min followed by 90 min of rest. Following 90 min of rest, participants were provided with an ad libitum meal for a fixed duration of 30 min. Blood samples and subjective appetite were collected and assessed before, during, immediately post-, 45 min post-, and 90 min post-exercise. The exercise increased estradiol (327 %) and progesterone (681 %) in the LP more than the FP respectively (P < 0.001, f = 1.33; P < 0.001,f = 1.20). There were no between-trial differences in appetite-regulating hormones, subjective appetite, or energy intake of ad libitum meal. These findings indicate that exercise-induced increases in ovarian hormones in the LP may not influence appetite-regulating hormones in physically active women.

Concurrent Validity of the Adult Eating Behavior Questionnaire in a Canadian Sample

The current study aimed to test the factor structure of the Adult Eating Behavior Questionnaire (AEBQ), its construct validity against the Three-Factor Eating Questionnaire (TFEQ-R18) and its associations with body mass index (BMI) in Canadian adults (n = 534, 76% female). Confirmatory factor analysis (CFA) revealed that a seven-factor AEBQ model, with the Hunger subscale removed, had better fit statistics than the original eight-factor structure. Cronbach's alpha was used to assess the internal reliability of each subscale and resulted with α > 0.70 for all subscales except for Hunger (α = 0.68). Pearson's correlations were used to inform the convergent and discriminant validation of AEBQ against the TFEQ-R18 and to examine the relationship between AEBQ and BMI. All AEBQ Food Approach subscales positively correlated with that of the TFEQ-R18 Emotional Eating and Uncontrolled Eating subscales. Similarly, BMI correlated positively with Food Approach subscales (except Hunger) and negatively with Food Avoidance subscales (except Food Fussiness). These results support the use of a seven-factor AEBQ for adults self-reporting eating behaviors, construct validity of the AEBQ against TFEB-R18, and provide further evidence for the association of these traits with BMI.

The use of Caralluma fimbriata as an appetite suppressant and weight loss supplement: a systematic review and meta-analysis of clinical trials

BACKGROUND

Obesity prevalence has increased during the past few decades, causing a pandemic with an influx in other co-morbidities. Many factors influence weight gain in an obesogenic environment therefore strategies for treating obesity may vary from conventional dietary and physical activity interventions to pharamacotherapy. A shift in unconventional strategies as herbal products for treating obesity have been investigated and one such plant extract is Caralluma fimbriata (C. fimbriata). Further, the studies included were systematically reviewed to gather evidence on potential effects of C. fimbriata as an appetite suppressant and weight loss supplement.

METHODS

A systematic review of clinical trials reporting the effects of C. fimbriata as appetite suppression and anti-obesity supplement was reported according to PRISMA guidelines. Data were obtained by searching three databases: PubMed®, Web of Science® and SciVerse Scopus® for studies published until 30th April 2020.

RESULTS

A total of 7 articles studying C. fimbriata satisfied the inclusion and exclusion criteria and were sourced from various countries including Australia (3), Cuba (1), India (2) and Spain (1). Almost all studies recruited adults who were overweight or obese with a BMI > 25 kg/m² (n = 5), with the exception of two studies, one that recruited healthy adults with a BMI average of 26.5 kg/m2 and the second one utilised a population of children and adolescents with Prader-Willis Syndrome (PWS). Parameters assessing obesity, biochemical and appetite factors were analysed by carrying out a meta-analysis. Compared to placebo controlled group, C. fimbriata extract significantly reduced WC by 1.59 cm (95% CI, - 3.07 to - 0.10, p = 0.041) and WHR by 0.06 (95% CI, - 0.12 to - 0.01, p = 0.05) although no significant effects were seen on BW, BMI and HC. Biochemical and appetite parameters outcome on C. fimbriata consumption had no significant changes. Any side effects of individuals who ingested the extract were reported by few studies of which most common effects were constipation, diarrhoea, nausea and rashes.

CONCLUSION

Appetite parameters showed no significant changes and metabolic parameters did not improve with C.fimbriata supplementation therefore it is unlikely to recommend C. fimbriata as a weight loss supplement and an appetite suppressant.