Hindbrain Double-Negative Feedback Mediates Palatability-Guided Food and Water Consumption.

Hunger and thirst have distinct goals but control similar ingestive behaviors, and little is known about neural processes that are shared between these behavioral states. We identify glutamatergic neurons in the peri-locus coeruleus (periLCVGLUT2 neurons) as a polysynaptic convergence node from separate energy-sensitive and hydration-sensitive cell populations. We develop methods for stable hindbrain calcium imaging in free-moving mice, which show that periLCVGLUT2 neurons are tuned to ingestive behaviors and respond similarly to food or water consumption. PeriLCVGLUT2 neurons are scalably inhibited by palatability and homeostatic need during consumption. Inhibition of periLCVGLUT2 neurons is rewarding and increases consumption by enhancing palatability and prolonging ingestion duration. These properties comprise a double-negative feedback relationship that sustains food or water consumption without affecting food- or water-seeking. PeriLCVGLUT2 neurons are a hub between hunger and thirst that specifically controls motivation for food and water ingestion, which is a factor that contributes to hedonic overeating and obesity.

ASICs Mediate Food Responses in an Enteric Serotonergic Neuron that Controls Foraging Behaviors.

Animals must respond to the ingestion of food by generating adaptive behaviors, but the role of gut-brain signaling in behavioral regulation is poorly understood. Here, we identify conserved ion channels in an enteric serotonergic neuron that mediate its responses to food ingestion and decipher how these responses drive changes in foraging behavior. We show that the C. elegans serotonergic neuron NSM acts as an enteric sensory neuron that acutely detects food ingestion. We identify the novel and conserved acid-sensing ion channels (ASICs) DEL-7 and DEL-3 as NSM-enriched channels required for feeding-dependent NSM activity, which in turn drives slow locomotion while animals feed. Point mutations that alter the DEL-7 channel change NSM dynamics and associated behavioral dynamics of the organism. This study provides causal links between food ingestion, molecular and physiological properties of an enteric serotonergic neuron, and adaptive feeding behaviors, yielding a new view of how enteric neurons control behavior.

A Neural Circuit for the Suppression of Pain by a Competing Need State.

Hunger and pain are two competing signals that individuals must resolve to ensure survival. However, the neural processes that prioritize conflicting survival needs are poorly understood. We discovered that hunger attenuates behavioral responses and affective properties of inflammatory pain without altering acute nociceptive responses. This effect is centrally controlled, as activity in hunger-sensitive agouti-related protein (AgRP)-expressing neurons abrogates inflammatory pain. Systematic analysis of AgRP projection subpopulations revealed that the neural processing of hunger and inflammatory pain converge in the hindbrain parabrachial nucleus (PBN). Strikingly, activity in AgRP → PBN neurons blocked the behavioral response to inflammatory pain as effectively as hunger or analgesics. The anti-nociceptive effect of hunger is mediated by neuropeptide Y (NPY) signaling in the PBN. By investigating the intersection between hunger and pain, we have identified a neural circuit that mediates competing survival needs and uncovered NPY Y1 receptor signaling in the PBN as a target for pain suppression.

Negative energy balance hinders prosocial helping behavior.

The internal state of an animal, including homeostatic requirements, modulates its behavior. Negative energy balance stimulates hunger, thus promoting a range of actions aimed at obtaining food. While these survival actions are well established, the influence of the energy status on prosocial behavior remains unexplored. We developed a paradigm to assess helping behavior in which a free mouse was faced with a conspecific trapped in a restrainer. We measured the willingness of the free mouse to liberate the confined mouse under diverse metabolic conditions. Around 42% of ad libitum-fed mice exhibited a helping behavior, as evidenced by the reduction in the latencies to release the trapped cagemate. This behavior was independent of subsequent social contact reward and was associated with changes in corticosterone indicative of emotional contagion. This decision-making process was coupled with reduced blood glucose excursions and higher Adenosine triphosphate (ATP):Adenosine diphosphate (ADP) ratios in the forebrain of helper mice, suggesting that it was a highly energy-demanding process. Interestingly, chronic (food restriction and type 2 diabetes) and acute (chemogenetic activation of hunger-promoting AgRP neurons) situations mimicking organismal negative energy balance and enhanced appetite attenuated helping behavior toward a distressed conspecific. To investigate similar effects in humans, we estimated the influence of glycated hemoglobin (a surrogate of long-term glycemic control) on prosocial behavior (namely charity donation) using the Understanding Society dataset. Our results evidenced that organismal energy status markedly influences helping behavior and that hypothalamic AgRP neurons are at the interface of metabolism and prosocial behavior.

Using transfer learning-based plant disease classification and detection for sustainable agriculture.

Subsistence farmers and global food security depend on sufficient food production, which aligns with the UN's "Zero Hunger," "Climate Action," and "Responsible Consumption and Production" sustainable development goals. In addition to already available methods for early disease detection and classification facing overfitting and fine feature extraction complexities during the training process, how early signs of green attacks can be identified or classified remains uncertain. Most pests and disease symptoms are seen in plant leaves and fruits, yet their diagnosis by experts in the laboratory is expensive, tedious, labor-intensive, and time-consuming. Notably, how plant pests and diseases can be appropriately detected and timely prevented is a hotspot paradigm in smart, sustainable agriculture remains unknown. In recent years, deep transfer learning has demonstrated tremendous advances in the recognition accuracy of object detection and image classification systems since these frameworks utilize previously acquired knowledge to solve similar problems more effectively and quickly. Therefore, in this research, we introduce two plant disease detection (PDDNet) models of early fusion (AE) and the lead voting ensemble (LVE) integrated with nine pre-trained convolutional neural networks (CNNs) and fine-tuned by deep feature extraction for efficient plant disease identification and classification. The experiments were carried out on 15 classes of the popular PlantVillage dataset, which has 54,305 image samples of different plant disease species in 38 categories. Hyperparameter fine-tuning was done with popular pre-trained models, including DenseNet201, ResNet101, ResNet50, GoogleNet, AlexNet, ResNet18, EfficientNetB7, NASNetMobile, and ConvNeXtSmall. We test these CNNs on the stated plant disease detection and classification problem, both independently and as part of an ensemble. In the final phase, a logistic regression (LR) classifier is utilized to determine the performance of various CNN model combinations. A comparative analysis was also performed on classifiers, deep learning, the proposed model, and similar state-of-the-art studies. The experiments demonstrated that PDDNet-AE and PDDNet-LVE achieved 96.74% and 97.79%, respectively, compared to current CNNs when tested on several plant diseases, depicting its exceptional robustness and generalization capabilities and mitigating current concerns in plant disease detection and classification.

Projecting the Contribution of Provitamin A Maize Biofortification and Other Nutrition Interventions to the Nutritional Adequacy and Cost of Diets in Rural Zimbabwe.

BACKGROUND: Evidence of the effectiveness of biofortified maize with higher provitamin A (PVA) to address vitamin A deficiency in rural Africa remains scant. OBJECTIVES: This study projects the impact of adopting PVA maize for a diversity of households in an area typical of rural Zimbabwe and models the cost and composition of diets adequate in vitamin A. METHODS: Household-level weighed food records were generated from 30 rural households during a week in April and November 2021. Weekly household intakes were calculated, as well as indicative costs of diets using data from market surveys. The impact of PVA maize adoption was modeled assuming all maize products contained observed vitamin A concentrations. The composition and cost of the least expensive indicative diets adequate in vitamin A were calculated using linear programming. RESULTS: Very few households would reach adequate intake of vitamin A with the consumption of PVA maize. However, from a current situation of 33%, 50%-70% of households were projected to reach ≥50% of their requirements (the target of PVA), even with the modest vitamin A concentrations achieved on-farm (mean of 28.3 µg RAE per 100 g). This proportion would increase if higher concentrations recorded on-station were achieved. The estimated daily costs of current diets (mean ± standard deviation) were USD 1.43 ± 0.59 in the wet season and USD 0.96 ± 0.40 in the dry season. By comparison, optimization models suggest that diets adequate in vitamin A could be achieved at daily costs of USD 0.97 and USD 0.79 in the wet and dry seasons, respectively. CONCLUSIONS: The adoption of PVA maize would bring a substantial improvement in vitamin A intake in rural Zimbabwe but should be combined with other interventions (e.g., diet diversification) to fully address vitamin A deficiency.

PACE: a Novel Eating Behavior Phenotype to Assess Risk for Obesity in Middle Childhood.

BACKGROUND: Behavioral phenotypes that predict future weight gain are needed to identify children susceptible to obesity. OBJECTIVES: This prospective study developed an eating behavior risk score to predict change in adiposity over 1 y in children. METHODS: Data from 6 baseline visits (Time 1, T1) and a 1-y follow-up visit (Time 2, T2) were collected from 76, 7- to 8-y-old healthy children recruited from Central Pennsylvania. At T1, children had body mass index (BMI) percentiles <90 and were classified with either high (n = 33; maternal BMI ≥30 kg/m2) or low (n = 43; maternal BMI ≤25 kg/m2) familial risk for obesity. Appetitive traits and eating behaviors were assessed at T1. Adiposity was measured at T1 and T2 using dual-energy x-ray absorptiometry, with a main outcome of fat mass index (FMI; total body fat mass divided by height in meters squared). Hierarchical linear regressions determined which eating measures improved prediction of T2 FMI after adjustment for covariates in the baseline model (T1 FMI, sex, income, familial risk, and Tanner stage). RESULTS: Four eating measures-Portion susceptibility, Appetitive traits, loss of control eating, and eating rate-were combined into a standardized summary score called PACE. PACE improved the baseline model to predict 80% variance in T2 FMI. PACE was positively associated with the increase in FMI in children from T1 to T2, independent of familial risk (r = 0.58, P < 0.001). Although PACE was higher in girls than boys (P < 0.05), it did not differ by familial risk, income, or education. CONCLUSIONS: PACE represents a cumulative eating behavior risk score that predicts adiposity gain over 1 y in middle childhood. If PACE similarly predicts adiposity gain in a cohort with greater racial and socioeconomic diversity, it will inform the development of interventions to prevent obesity. This trial was registered at clinicaltrials.gov as NCT03341247.

Food insecurity in pediatric HIV: understanding a critical challenge in the United States.

Advancing the well-being of individuals living with HIV necessitates attention to social determinants of health, including food insecurity. Through a clinical and community-based needs assessment, we aimed to gain insight into experiences of food insecurity among patients receiving care at a large pediatric HIV outpatient clinic in the Southeastern United States. We adopted a multimodal assessment approach involving a literature review, community profiling, key informant interviews, focus group discussions with staff, patients and parents and a community stakeholder advisory meeting. Our needs assessment demonstrates that food insecurity is an important aspect of the lived experience of children, adolescents and young adults living with HIV. Clinical staff agreed that food insecurity screening should be incorporated into the patient care workflow but ideally only in concert with providing resources that meet their needs. We formulated a recommendation matrix for addressing food insecurity based on priority importance and feasibility. Collaborative relationships between healthcare practitioners and leaders, community-based organizations and local and federal funding sources are vital for enhancing patients' access to sustainable, reliable solutions to this fundamental determinant of health. Our approach provides a tested model for other clinics seeking to identify and alleviate food insecurity among patients.

Pre-prandial plasma liver-expressed antimicrobial peptide 2 (LEAP2) concentration in humans is inversely associated with hunger sensation in a ghrelin independent manner.

PURPOSE: The liver-expressed antimicrobial peptide 2 (LEAP2) is a newly recognized peptide hormone that acts via the growth hormone secretagogue receptor (GHSR) blunting the effects of ghrelin and displaying ghrelin-independent actions. Since the implications of LEAP2 are beginning to be elucidated, we investigated if plasma LEAP2 concentration varies with feeding status or sex and whether it is associated with glucose metabolism and appetite sensations. METHODS: We performed a single test meal study, in which plasma concentrations of LEAP2, ghrelin, insulin and glucose as well as visual analogue scales for hunger, desire to eat, prospective food consumption, fullness were assessed before and 60 min after breakfast in 44 participants (n = 21 females) with normal weight (NW) or overweight/obesity (OW/OB). RESULTS: Pre-prandial plasma LEAP2 concentration was ~ 1.6-fold higher whereas ghrelin was ~ 2.0-fold lower in individuals with OW/OB (p < 0.001) independently of sex. After adjusting for body mass index (BMI) and sex, pre-prandial plasma LEAP2 concentration displayed a direct relationship with BMI (ß: 0.09; 95%CI: 0.05, 0.13; p < 0.001), fat mass (ß: 0.05; 95%CI: 0.01, 0.09; p = 0.010) and glycemia (ß: 0.24; 95%CI: 0.05, 0.43; p = 0.021), whereas plasma ghrelin concentration displayed an inverse relationship with BMI and fat mass but not with glycemia. Postprandial plasma LEAP2 concentration increased ~ 58% in females with OW/OB (p = 0.045) but not in females with NW or in males. Pre-prandial plasma LEAP2 concentration displayed an inverse relationship with hunger score (ß: - 11.16; 95% CI: - 18.52, - 3.79; p = 0.004), in a BMI-, sex- and ghrelin-independent manner. CONCLUSIONS: LEAP2 emerges as a key hormone implicated in the regulation of metabolism and appetite in humans. TRIAL REGISTRATION: The study was retrospectively registered in clinicaltrials.gov (April 2023). CLINICALTRIALS: gov Identifier: NCT05815641.

High manifestations of food insecurity and hunger among pregnant and lactating women during post-conflict in Tigray, Ethiopia: a community-based study.

BACKGROUND: Food insecurity is a state or condition in which people have limited or uncertain physical, social, and economic access to safe, sufficient, and nutritious food to meet their dietary needs. Since no thorough evaluation was carried out to determine the degree of household food insecurity in Tigrayan communities in the aftermath of the conflict. This study aims to describe household-level food insecurity status among pregnant and lactating women during the post-armed conflict in Tigray, Ethiopia. METHOD: Descriptive research was designed to assess household food insecurity. A multi-stage sampling technique was used for this study. One thousand two hundred forty-nine households were selected systematically following a list of food insecure households. Descriptive statistical values, including frequency counts, percentages, minimum values, maximum values, and averages, were calculated to quantify the indicators under study. Household food insecurity and hunger Scale measurement using the standardized Food and Agriculture Organization standard. RESULTS: The mean age (± SD) of the mothers was 28.35 ± 5.91 years. More than three fourth of the participants 1010(80.93%) were rural residents. The survey result showed that 88.8% of the pregnant and lactating were food insecure. Half (50.1%) of the households were hungry,one month before the study, 78.5% of the families expressed concern about running out of food and 6.4% had severe hunger. CONCLUSIONS: The food insecurity levels and hunger prestige of the study communities were excessively high. This is in the context of a region affected by intense armed conflict. It is commended that the study communities need to be safeguarded from the direct and long-term consequences of armed conflict-caused household food insecurity.

How did the use of the social marketing approach in Egyptian communities succeed in improving breastfeeding practices and infants' growth?

INTRODUCTION: Improving breastfeeding practices does not always link to interventions relying only on improving nutrition awareness and education but needs cultural and behavioral insights . AIM: This study aimed to evaluate the changes in core breastfeeding indicators as a result of the use of social marketing (SM) approach for improving breastfeeding practices of Egyptian women and the physical growth of infants aged 6 to 12 months. The core breastfeeding indicators were: Early initiation of breastfeeding within one hour of birth, Predominant and exclusive breastfeeding to 6 months (EBF), Bottle feeding with formula, continued breastfeeding to 1 and 2 years, and responsiveness to cues of hunger and satiety. METHODS: A quasi-experimental longitudinal study with a posttest-only control design was done over 3 years in three phases; the first was in-depth interviews and formative research followed by health education and counseling interventions and ended by measuring the outcome. Motivating mothers' voluntary behaviors toward breastfeeding promotion "feeding your baby like a baby" was done using SM principles: product, price, place, and promotion. The interventions targeted 646 pregnant women in their last trimester and delivered mothers and 1454 women in their childbearing period. The statistical analysis was done by using SPSS program, version 26. RESULTS: Most mothers showed significantly increased awareness about the benefits of breastfeeding and became interested in breastfeeding their children outside the house using the breastfeeding cover (Gawn) (p < 0.05). Breastfeeding initiation, exclusive breastfeeding under 6 months, frequency of breastfeeding per day, and percentage of children who continued breastfeeding till 2 years, were significantly increased (from 30%, 23%, 56%, and 32% to 62%, 47.3%, 69%, and 43.5% respectively). The girls who recorded underweight results over boys during the first year of life were significantly improved (p < 0.01) after the intervention (from 52.1% to 18.8% respectively). At the same time, girls found to be obese before the intervention (15.6%) became no longer obese. CONCLUSIONS: Improvement for the majority of the key breastfeeding indicators and physical growth of infants indicates that raising a healthy generation should start by promoting breastfeeding practices that are respectable to societal norms.

Differential changes in appetite hormones post-prandially based on menstrual cycle phase and oral contraceptive use: A preliminary study.

This was a preliminary study that examined whether appetite regulation is altered during the menstrual cycle or with oral contraceptives. Ten naturally cycling females (NON-USERS) and nine tri-phasic oral contraceptive using females (USERS) completed experimental sessions during each menstrual phase (follicular phase: FP; ovulatory phase: OP; luteal phase: LP). Appetite perceptions and blood samples were obtained fasted, 30, 60, and 90 min post-prandial to measure acylated ghrelin, active glucagon-like peptide-1 (GLP-1), and total peptide tyrosine tyrosine (PYY). Changes were considered important if p < 0.100 and the effect size was ≥medium. There appeared to be a three-way (group x phase x time) interaction for acylated ghrelin where concentrations appeared to be greater in USERS versus NON-USERS during the OP 90-min post-prandial and during the LP fasted, and 90-min post-prandial. In USERS, ghrelin appeared to be greater 90-min post-prandial in the OP versus the FP with no other apparent differences between phases. There were no apparent differences between phases in NON-USERS. There appeared to be a three-way interaction for PYY where concentrations appeared to be greater in USERS during the FP 60-min post-prandial and during the OP 30-min post-prandial. In USERS PYY appeared to be greater 60-min post-prandial during the OP versus the LP with no other apparent differences. There were no apparent differences between phases in NON-USERS. There appeared to be no effect of group or phase on GLP-1, or appetite perceptions. These data demonstrate small effects of menstrual cycle phase and oral contraceptive use on the acylated ghrelin and total PYY response to a standardized meal, with no effects on active GLP-1 or perceived appetite, though more work with a large sample size is necessary.

The role of the community café in addressing food security: Perceptions of managers and directors.

In the United States, the pay-what-you-can restaurant model (community cafes) is an increasingly popular approach to addressing food insecurity in local communities. We conducted semi-structured interviews (n = 13) with community café executive managers and directors to assess their perceptions of the role that their cafes play in addressing food security (FS). Analysis of interviews revealed two major areas of emphasis by participants. Filling an unoccupied space in the food security landscape. Interviewees regularly cited the goal of making meals available through a dependable schedule, convenient location, and welcoming atmosphere for guests to promote regular visits to the café, and they did so with an awareness of how their practices were shaped by perceived shortcomings in comparable services. In addition, guest agency and social aspects of the café as components of utilization, was another major area. Interviewees often regarded the opportunity of the food insecure guest to choose healthy options (i.e., nutritionally dense) over less healthful ones (i.e., calorically dense) from the menu as a critical component of their service. The social component of the café (e.g., community atmosphere, 'dining-out' experience) was another aspect of the café's function that promoted dignity for the guest which can lead to greater likelihood of return visits. Perceptions shared by participants of the café's role in addressing food security suggest that rather than simply adding to the available options of hunger relief services, the café model attempts to address many areas of concern, such as structural and cultural barriers, found in the traditional forms of charitable food provision.

Parent-offspring similarity in hunger and thirst sensations.

The internal (i.e., interoceptive) sensations that characterise hunger vary between people, and this may also be the case for thirst, although it has not been so well explored. There are probably both heritable and learning-based causes for this interoceptive variability. Consequently, it would seem plausible that parents and their offspring would have more similar patterns of hunger and thirst than pairs of strangers. We tested this idea, in addition to exploring its potential moderating variables, by studying the similarity of self-reported hunger and thirst sensations in 170 students and their primary caregivers from childhood. Both students and caregivers completed the same online-survey, covering hunger and thirst sensations, beliefs about the causes of hunger and thirst, the Three Factor Eating Questionnaire (revised) and demographic data. We find evidence of robust student-caregiver similarity in interoceptive hunger and thirst sensations (medium effect sizes), with these being moderated by caregiver beliefs about the homeostatic nature of each state (medium effect sizes). This suggests a potential role for caregivers in the development of their offspring's interoceptive cues for hunger and for thirst. In addition, thirst, like hunger, appears to be multidimensional, and varies between people. The implications of these findings are discussed.

The impact of acute and chronic resistance training on appetite and energy intake: A scoping review examining resistance exercise and comparisons with other exercise modalities.

PURPOSE: The effects of exercise on appetite have recently been systematically evaluated with a focus on endurance training (ET). However, resistance training (RT) may induce different adaptations than ET. This scoping review aimed to examine the acute and chronic effects of isolated RT and comparisons with other exercise modalities on appetite-related variables and energy intake. RESULTS: 17 acute studies were identified, six examining isolated RT, while 11 focused on RT intensity, amount of exercise, targeted muscle groups, or comparison with ET and combined training (RT plus ET; CT). Nine chronic studies were identified. Three investigated isolated RT vs control and six manipulated the amount of RT exercise, types of RT, or comparison with ET and CT. CONCLUSIONS: Acute RT compared to control conditions appears to induce responses favoring appetite inhibition. While the amount of RT exercise may acutely play a role in the suppression of appetite, while ET seems to have more potential to suppress appetite. Chronic RT does not seem to stimulate compensatory mechanisms; however, there is not clear evidence regarding the role of RT intensity or other exercise modalities. Chronic ET and CT may be more prone to favor appetite inhibition than RT. More comprehensive evaluations including the exploration of multiple appetite-related factors are needed for future studies.

Adaptive and maladaptive emotion regulation skills are associated with food intake following a hunger-induced increase in negative emotions.

Many individuals would like to lose weight and often attempt to do so by dieting. However, dieting attempts often backfire and contribute to the risk of weight gain and obesity. Food restriction inevitably leads to hunger and hunger, in turn, induces negative emotions. The inability to regulate such a hunger-induced increase in negative emotions in an adaptive way may be responsible for overeating. The current study aimed to gain a better understanding of this potential psychological mechanism underlying failed dieting attempts. Adaptive and maladaptive emotion regulation (ER) were assessed with an online questionnaire in women with a healthy weight. Subsequently, participants were assigned to the fasted condition (fasting for 14h, n = 49) or the satiated condition (eating between 2 h and 30 min before the lab session, n = 59) and attended a lab session in which they completed tasks while given the opportunity to eat chips and M&M's. We did not find an association between any ER variable and the likelihood to begin eating. Among those who began eating, higher scores on adaptive cognitive ER and on maladaptive behavioral ER were associated with lower caloric intake in fasted individuals. Higher scores on adaptive behavioral ER were associated with higher caloric intake in fasted individuals. Utilizing adaptive cognitive ER when experiencing a hunger-induced increase in negative emotions may help individuals manage their food intake and maintain a healthy weight.

Augmented gut hormone response to feeding in older adults exhibiting low appetite.

Age-related changes in gut hormones may play a role in anorexia of ageing. The aim of this study was to determine concentrations of ghrelin, PYY, and GLP-1 in older adults exhibiting an anorexia of ageing phenotype. Thirteen older adults with healthy appetite (OA-HA; 8f, 75 ± 7 years, 26.0 ± 3.2 kg m-2), fifteen older adults with low appetite (OA-LA; 10f, 72 ± 7 years, 23.6 ± 3.1 kg m-2), and twelve young adults (YA; 6f, 22 ± 2 years, 24.4 ± 2.0 kg m-2) completed the study. Healthy appetite and low appetite were determined based on BMI, habitual energy intake, self-reported appetite, and laboratory-assessed ad libitum lunch intake. Participants provided a fasted measure of subjective appetite and blood sample (0 min) before consuming a standardised breakfast (450 kcal). Appetite was measured and blood samples were drawn throughout a 240-min rest period. At 240 min, an ad libitum lunch meal was consumed. Relative intake at lunch (expressed as percentage of estimated total energy requirement) was lower for OA-LA (19.8 ± 7.7%) than YA (41.5 ± 9.2%, p < 0.001) and OA-HA (37.3 ± 10.0%, p < 0.001). Ghrelin suppression was greater for OA-LA (net AUC, -78719 ± 74788 pg mL-1·240min-1) than both YA (-23899 ± 27733 pg mL-1·240min-1, p = 0.016) and OA-HA (-21144 ± 31161 pg mL-1·240min-1, p = 0.009). There were trends for higher GLP-1 concentrations in OA-LA compared with YA at 90 min (8.85 ± 10.4 pM vs. 1.88 ± 4.63 pM, p = 0.073) and 180 min (5.00 ± 4.71 pM vs. 1.07 ± 2.83 pM, p = 0.065). There was a trend for a greater PYY response for OA-LA compared with OA-HA (net AUC p = 0.062). "Anorexigenic response score" - a composite score of gut hormone responses to feeding - showed greater anorexigenic response in OA-LA, compared with YA and OA-HA. No differences were seen in subjective appetite. These observations suggest augmented anorexigenic responses of gut hormones to feeding may be causal mechanisms of anorexia of ageing.

Association between glucose dips and the feeling of hunger in a dietary intervention study among students with early and late chronotype-secondary analysis of a randomized cross-over nutrition trial.

Consumption of foods with high glycaemic index (GI) can cause hyperglycemia, thus increasing postprandial hunger. Since circadian rhythm differs inter-individually, we describe glucose dips after breakfast/dinner with high/medium estimated meal GI among students with early (n = 22) and late chronotype (n = 23) and examine their relation to the feeling of hunger in a secondary analysis of a randomized cross-over nutrition trial. Glucose dips reflect the difference between the lowest glucose value recorded 2-3 h postprandially and baseline, presented as percentage of average baseline level. Associations between glucose dips and the feeling of hunger were analyzed using multilevel linear models. Glucose dips were lower after medium GI meals than after high GI meals among both chronotype groups (p = 0.03). Among early chronotypes, but not among late chronotypes, glucose dip values were lower after breakfast than after dinner (-4.9 % vs. 5.5 %, p = 0.001). Hunger increased throughout the day among both chronotypes but glucose dips were not related to the feeling of hunger at the meal following breakfast. Interestingly, lower glucose dip values 2-3 h postprandially occurred particularly after medium GI meals and were seen after breakfast among early chronotypes. These glucose dips did not predict hunger at meals after breakfast.

Individual variability and consistency of post-exercise energy and macronutrient intake, appetite sensations, and food reward in healthy adults.

Limited evidence is available about the variability of appetitive responses within individuals after an acute bout of exercise. The present study aimed to assess the consistency and individual variability of post-exercise appetitive responses in healthy individuals. Twenty participants (10 females, 23.9 ± 4.1 years, 22.5 ± 2.0 kg m-2) joined the laboratory to perform four sessions separated by a minimum of 5 days: i) a control session with a rest period before and an ad libitum lunch (REST), and ii) three identical exercise sessions (EX) with a 30-min moderate-intensity (60-70% of predicted maximal heart rate) walking bout ending 25 min before the ad libitum lunch. Subjective appetite sensations were assessed before and after the meal at regular intervals, and satiety quotients were calculated. Food reward was assessed by the Leeds Food Preference Questionnaire before and after lunch. For each EX session, the difference with the REST session was calculated (Δ = EX - REST). Energy and macronutrient intake were consistent in response to exercise (all intraclass correlation coefficients (ICC) > 0.8) while results showed that post-exercise subjective appetite sensations and satiety quotients varied across the three EX sessions (almost all ICC < 0.7). Food reward was overall consistent in response to exercise before the test meal but not after. When considering the changes (Δ), the results showed no or poor consistency for most of the appetitive outcomes. To conclude, energy and macronutrient intake, as well as pre-meal food reward, are consistent after exercise in healthy individuals, while subjective appetite sensations are not stable within individuals across the sessions. Regarding the variations from REST to EX sessions, the results suggest that the individual changes observed are only random day-to-day variations.

Not feeling the heat? Effects of dietary protein on satiation and satiety in mice are not due to its impact on body temperature.

Dietary protein modulates food intake (FI) via unclear mechanism(s). One possibility is that higher protein leads to greater post-ingestive heat production (Specific dynamic action: SDA) leading to earlier meal termination (increased satiation), and inhibition of further intake (increased satiety). The influence of dietary protein on feeding behaviour in C57BL/6J mice was tested using an automated FI monitoring system (BioDAQ), simultaneous to body temperature (Tb). Total FI, inter meal intervals (IMI, satiety) and meal size (MS, satiation) were related to changes in Tb after consuming low (5%, LP), moderate (15%, MP) and high (30%, HP) protein diets. Diets were tested over three conditions: 1) room temperature (RT, 21 ± 1 °C), 2) room temperature and running wheels (RTRW) and 3) low temperature (10 °C) and running wheels (LTRW). The differences between diets and conditions were also compared using mixed models. Mice housed at RT fed HP diet, reduced total FI compared with LP and MP due to earlier meal termination (satiation effect). FI was lowered in RTRW conditions with no differences between diets. FI significantly increased under LTRW conditions for all diets, with protein content leading to earlier meal termination (satiation) but not the intervals between feeding bouts (satiety). Tb fell immediately after feeding in all conditions. Despite a reduction in total FI in mice fed HP, mediated via increased satiation, this effect was not linked to increased Tb during meals. We conclude effects of dietary protein on intake are not mediated via SDA and Tb.