Influence of Nutrition Claims on Appetite Sensations according to Sex, Weight Status, and Restrained Eating

Hallmarks of Appetite: A Comprehensive Review of Hunger, Appetite, Satiation, and Satiety

PURPOSE OF REVIEW

The present review describes the available literature on the physiologic mechanisms that modulate hunger, appetite, satiation, and satiety with a particular focus on well-established and emerging factors involved in the classic satiety cascade model.

RECENT FINDING

Obesity is a significant risk factor for numerous chronic conditions like cancer, cardiovascular diseases, and diabetes. As excess energy intake is considered by some to be the primary driver of weight gain, tremendous collective effort should be directed toward reducing excessive feeding at the individual and population levels. From this perspective, detailed understanding of physiologic mechanisms that control appetite, and in turn, the design of effective interventions to manage appetite, may represent key strategies in controlling the obesity epidemic. With the obesity's prevalence on the rise worldwide, research on hunger, appetite, satiation and satiety is more relevant than ever. This research aims to provide practical insights for medical practitioners, nutrition professionals, and the broader scientific community in the fight against this global health challenge.

Differences in gastrointestinal hormones and appetite ratings between individuals with and without obesity-A systematic review and meta-analysis

Determining if gastrointestinal (GI) hormone response to food intake differs between individuals with, and without, obesity may improve our understanding of obesity pathophysiology. A systematic review and meta-analysis of studies assessing the concentrations of GI hormones, as well as appetite ratings, following a test meal, in individuals with and without obesity was undertaken. Systematic searches were conducted in the databases MEDLINE, Embase, Cochrane Library, PsycINFO, Web of Science, and ClinicalTrials.gov. A total of 7514 unique articles were retrieved, 115 included in the systematic review, and 70 in the meta-analysis. The meta-analysis compared estimated standardized mean difference in GI hormones' concentration, as well as appetite ratings, between individuals with and without obesity. Basal and postprandial total ghrelin concentrations were lower in individuals with obesity compared with controls, and this was reflected by lower postprandial hunger ratings in the former. Individuals with obesity had a lower postprandial concentration of total peptide YY compared with controls, but no significant differences were found for glucagon-like peptide 1, cholecystokinin, or other appetite ratings. A large methodological and statistical heterogeneity among studies was found. More comprehensive studies are needed to understand if the differences observed are a cause or a consequence of obesity.

Race/ethnicity and gender modify the association between diet and cognition in U.S. older adults: National Health and Nutrition Examination Survey 2011-2014

INTRODUCTION

It is unclear whether the association between Mediterranean-type Diet (MeDi) and cognition is similar across different racial/ethnic groups or between women and men.

METHODS

The current study included 2435 participants (≥60 years of age) of the National Health and Nutrition Examination Survey (NHANES) 2011-2014. Linear regression models were applied to examine the association between diet and cognition, adjusted for multiple demographic variables. Interaction between MeDi and race/ethnicity (non-Hispanic White, non-Hispanic Black, Hispanic, other), and between MeDi and gender, were examined, followed by stratified analyses.

RESULTS

One score increase in MeDi was associated with 0.039 (95%confidence interval [CI] = 0.016-0.062) higher global cognitive z-score. Significant associations between MeDi and global cognition and between MeDi and immediate recall were found in the non-Hispanic Whites only (P-interaction = 0.057 and 0.059, respectively). MeDi was associated with increased score of animal fluency score in men but not in women (P-interaction = 0.082).

DISCUSSION

The positive association between MeDi and cognition might be dependent on race/ethnicity and gender.

The Role of Neuropeptide Y and Peptide YY in the Development of Obesity via Gut-brain Axis

Obesity is one of the main challenges of public health in the 21st century. Obesity can induce a series of chronic metabolic diseases, such as diabetes, dyslipidemia, hypertension and nonalcoholic fatty liver, which seriously affect human health. Gut-brain axis, the two-direction pathway formed between enteric nervous system and central nervous system, plays a vital role in the occurrence and development of obesity. Gastrointestinal signals are projected through the gut-brain axis to nervous system, and respond to various gastrointestinal stimulation. The central nervous system regulates visceral activity through the gut-brain axis. Brain-gut peptides have important regulatory roles in the gut-brain axis. The brain-gut peptides of the gastrointestinal system and the nervous system regulate the gastrointestinal movement, feeling, secretion, absorption and other complex functions through endocrine, neurosecretion and paracrine to secrete peptides. Both neuropeptide Y and peptide YY belong to the pancreatic polypeptide family and are important brain-gut peptides. Neuropeptide Y and peptide YY have functions that are closely related to appetite regulation and obesity formation. This review describes the role of the gutbrain axis in regulating appetite and maintaining energy balance, and the functions of brain-gut peptides neuropeptide Y and peptide YY in obesity. The relationship between NPY and PYY and the interaction between the NPY-PYY signaling with the gut microbiota are also described in this review.

Dietary behaviors mediate the association between food insecurity and obesity among socioeconomically disadvantaged youth

Across many Asian countries, the prevalence of obesity is increasing and is increasingly recognized as an emerging public health issue. Food insecurity, defined as the limited or uncertain availability of nutritionally adequate and safe foods, is major difficulty faced by many poor subpopulations despite national economic growth. Previous research has yielded inconsistent results about the association between food insecurity and obesity, with positive associations more consistently observed among women than men. This study aims to elucidate relationships between food insecurity, dietary behaviors, and weight status, stratified by gender. Data come from the Taiwan Database of Children and Youth in Poverty. Participants (n = 1326) aged 10-18 years (2009-2013), which included measures of food security and dietary behaviors in three survey waves. Weight status was determined using self-reported body mass index (BMI; kg/m²) with the category "overweight/obesity" defined as a BMI above the 85th percentile within a representative population. Logistic regression analyses indicated a significant association between food insecurity and obesity/overweight with an odds ratio (OR) = 1.45, 95% confidence interval (CI) 1.25-1.70. Food insecurity was associated with a select number of unhealthy dietary behaviors. Skipping breakfast in females (OR = 1.63, 95% CI 1.20-2.22) and consuming snacks and sugared drinks in males (OR = 1.51, 95% CI 1.15-1.98) were associated with obesity/overweight. Food insecurity remained significantly associated with obesity/overweight after adjusting for dietary behaviors. In addition, there was some evidence that dietary behaviors mediated the association between food security and obesity/overweight. In conclusion, economically disadvantaged youth are vulnerable to food insecurity and obesity, and food insecurity may increase the likelihood of obesity due to its association with dietary behaviors. Understanding the mediating factors between food insecurity and obesity may help to amend weight-related health problems in poverty-affected populations.

Users, Uses, and Effects of Social Media in Dietetic Practice: Scoping Review of the Quantitative and Qualitative Evidence

BACKGROUND

Social media platforms are increasingly used by registered dietitians (RDs) to improve knowledge translation and exchange in nutrition. However, a thorough understanding of social media in dietetic practice is lacking.

OBJECTIVE

The objective of this study was to map and summarize the evidence about the users, uses, and effects of social media in dietetic practice to identify gaps in the literature and inform future research by using a scoping review methodology.

METHODS

Stages for conducting the scoping review included the following: (1) identifying the research question; (2) identifying relevant studies through a comprehensive multidatabase and gray literature search strategy; (3) selecting eligible studies; (4) charting the data; and (5) collating, summarizing, and reporting results for dissemination. Finally, knowledge users (RDs working for dietetic professional associations and public health organizations) were involved in each review stage to generate practical findings.

RESULTS

Of the 47 included studies, 34 were intervention studies, 4 were descriptive studies, 2 were content analysis studies, and 7 were expert opinion papers in dietetic practice. Discussion forums were the most frequent social media platform evaluated (n=19), followed by blogs (n=13) and social networking sites (n=10). Most studies targeted overweight and obese or healthy users, with adult populations being most studied. Social media platforms were used to deliver content as part of larger multiple component interventions for weight management. Among intervention studies using a control group with no exposition to social media, we identified positive, neutral, and mixed effects of social media for outcomes related to users' health behaviors and status (eg, dietary intakes and body weight), participation rates, and professional knowledge. Factors associated with the characteristics of the specific social media, such as ease of use, a design for quick access to desired information, and concurrent reminders of use, were perceived as the main facilitators to the use of social media in dietetic practice, followed to a lesser extent by interactions with an RD and social support from fellow users. Barriers to social media use were mostly related to complicated access to the site and time issues.

CONCLUSIONS

Research on social media in dietetic practice is at its infancy, but it is growing fast. So far, this field of research has targeted few social media platforms, most of which were assessed in multiple-component interventions for weight management among overweight or obese adults. Trials isolating the effects and mechanisms of action of specific social media platforms are needed to draw conclusions regarding the effectiveness of those tools to support dietetic practice. Future studies should address barriers and facilitators related to the use of social media written by RDs and should explore how to make these tools useful for RDs to reach health consumers to improve health through diet.

Effects of walking in water on gut hormone concentrations and appetite: comparison with walking on land

The effects of water exercise on gut hormone concentrations and appetite currently remain unclear. The aim of the present study was to investigate the effects of treadmill walking in water on gut hormone concentrations and appetite. Thirteen men (mean ± s.d. age: 21.6 ± 2.2 years, body mass index: 22.7 ± 2.8 kg/m², peak oxygen uptake (VO_2peak): 49.8 ± 7.8 mL/kg per min) participated in the walking in water and on land challenge. During the study period, ratings of subjective feelings of hunger, fullness, satiety and motivation to eat were reported on a 100-mm visual analog scale. A test meal was presented after walking, and energy intake (EI) was calculated. Blood samples were obtained during both trials to measure glucagon-like peptide-1 (GLP-1), peptide YY (PYY) and acylated ghrelin (AG) concentrations. Hunger scores (How hungry do you feel?) were significantly lower during the water trial than during the land trial (P < 0.05). No significant differences were observed in EI between water and land trials. GLP-1 concentrations were significantly higher in the water trial than in the land trial (P < 0.05). No significant differences were observed in PYY concentrations between water and land trials. AG concentrations were significantly lower in the water trial than in the land trial (P < 0.01). In conclusion, changes in gut hormone concentrations during walking in water contribute to the exercise-induced suppression of appetite and provide novel information on the influence of walking in water on the acute regulation of appetite.