Explore the vast range of titles available.

Recent research indicates that the hypothalamic neuropeptide hormone oxytocin is a key central nervous system factor in the regulation of food intake and weight. However, the mechanisms underlying the anorexigenic effects of oxytocin in humans are unknown and critical to study to consider oxytocin as a neurohormonal weight loss treatment. We performed a randomized, double-blind, placebo-controlled crossover study with single-dose intranasal oxytocin (24 IU) in ten overweight or obese, otherwise healthy men. Following oxytocin/placebo administration, participants completed an established functional magnetic resonance imaging food motivation paradigm. We hypothesized that oxytocin would reduce the blood oxygenation level-dependent (BOLD) signal to high-calorie food vs non-food visual stimuli in the ventral tegmental area (VTA), the origin of the mesolimbic dopaminergic reward system. Following oxytocin administration, compared to placebo, participants showed bilateral VTA hypoactivation to high-calorie food stimuli. A secondary exploratory whole-brain analysis revealed hypoactivation in additional hedonic (orbitofrontal cortex, insula, globus pallidus, putamen, hippocampus, and amygdala) and homeostatic (hypothalamus) food motivation and hyperactivation in cognitive control (anterior cingulate and frontopolar cortex) brain regions following oxytocin administration vs placebo. Oxytocin administration reduces the BOLD signal in reward-related food motivation brain regions, providing a potential neurobiological mechanism for the anorexigenic oxytocin effects in humans. Furthermore, our data indicate that oxytocin administration reduces activation in homeostatic and increases activation in cognitive control brain regions critically involved in regulating food intake and resolving affective conflict, respectively. Future studies are required to link these changes in brain activation to oxytocin effects on food intake and weight.

Mosquito blood-feeding behavior is a key determinant of the epidemiology of dengue viruses (DENV), the most-prevalent mosquitoborne viruses. However, despite its importance, how DENV infection influences mosquito blood-feeding and, consequently, transmission remains unclear. Here, we developed a high-resolution, video-based assay to observe the blood-feeding behavior of Aedes aegypti mosquitoes on mice. We then applied multivariate analysis on the high-throughput, unbiased data generated from the assay to ordinate behavioral parameters into complex behaviors. We showed that DENV infection increases mosquito attraction to the host and hinders its biting efficiency, the latter resulting in the infected mosquitoes biting more to reach similar blood repletion as uninfected mosquitoes. To examine how increased biting influences DENV transmission to the host, we established an in vivo transmission model with immuno-competent mice and demonstrated that successive short probes result in multiple transmissions. Finally, to determine how DENV-induced alterations of host-seeking and biting behaviors influence dengue epidemiology, we integrated the behavioral data within a mathematical model. We calculated that the number of infected hosts per infected mosquito, as determined by the reproduction rate, tripled when mosquito behavior was influenced by DENV infection. Taken together, this multidisciplinary study details how DENV infection modulates mosquito blood-feeding behavior to increase vector capacity, proportionally aggravating DENV epidemiology. By elucidating the contribution of mosquito behavioral alterations on DENV transmission to the host, these results will inform epidemiological modeling to tailor improved interventions against dengue.

Functional magnetic resonance imaging is used to examine brain areas whose activity correlates with subsequent feeding behaviour under different satiety states evoked by intravenous peptide YY 3–36 (PYY), administration. Under high PYY conditions, (mimicking the fed state) changes in orbitofrontal cortex activation better predicted subsequent feeding, whereas in low PYY conditions, hypothalamic activation predicted food intake. The ability to maintain adequate nutrient intake is critical for survival. Complex interrelated neuronal circuits have developed in the mammalian brain to regulate many aspects of feeding behaviour, from food-seeking to meal termination. The hypothalamus and brainstem are thought to be the principal homeostatic brain areas responsible for regulating body weight 1 , 2 . However, in the current ‘obesogenic’ human environment food intake is largely determined by non-homeostatic factors including cognition, emotion and reward, which are primarily processed in corticolimbic and higher cortical brain regions 3 . Although the pleasure of eating is modulated by satiety and food deprivation increases the reward value of food, there is currently no adequate neurobiological account of this interaction between homeostatic and higher centres in the regulation of food intake in humans 1 , 4 , 5 . Here we show, using functional magnetic resonance imaging, that peptide YY 3–36 (PYY), a physiological gut-derived satiety signal, modulates neural activity within both corticolimbic and higher-cortical areas as well as homeostatic brain regions. Under conditions of high plasma PYY concentrations, mimicking the fed state, changes in neural activity within the caudolateral orbital frontal cortex predict feeding behaviour independently of meal-related sensory experiences. In contrast, in conditions of low levels of PYY, hypothalamic activation predicts food intake. Thus, the presence of a postprandial satiety factor switches food intake regulation from a homeostatic to a hedonic, corticolimbic area. Our studies give insights into the neural networks in humans that respond to a specific satiety signal to regulate food intake. An increased understanding of how such homeostatic and higher brain functions are integrated may pave the way for the development of new treatment strategies for obesity.

\"Bestselling author and economist Ha-Joon Chang makes challenging economic ideas delicious by plating them alongside stories about food from around the world, using the diverse histories behind familiar food items to explore economic theory. For Chang, chocolate is a lifelong addiction, but more exciting are the insights it offers into postindustrial knowledge economies; and while okra makes Southern gumbo heart-meltingly smooth, it also speaks of capitalism's entangled relationship with freedom. Myth-busting, witty, and thought-provoking, Edible Economics serves up a feast of bold ideas about globalization, climate change, immigration, austerity, automation, and why carrots need not be orange. It shows that getting to grips with the economy is like learning a recipe: when we understand it, we can adapt and improve it--and better understand our world.\"--Front book jacket flap.

Background/Objectives: Animal studies and pilot experiments in men indicate that the hypothalamic neuropeptide oxytocin limits food intake, and raise the question of its potential to improve metabolic control in obesity. Subjects/Methods: We compared the effect of central nervous oxytocin administration (24 IU) via the intranasal route on ingestive behaviour and metabolic function in 18 young obese men with the results in a group of 20 normal-weight men. In double-blind, placebo-controlled experiments, ad libitum food intake from a test buffet was examined in fasted subjects 45 min after oxytocin administration, followed by the assessment of postprandial, reward-driven snack intake. Energy expenditure was repeatedly assessed by indirect calorimetry and blood was sampled to determine concentrations of blood glucose and hormones. Results: Oxytocin markedly reduced hunger-driven food intake in the fasted state in obese but not in normal-weight men, and led to a reduction in snack consumption in both groups, whereas energy expenditure remained generally unaffected. Hypothalamic–pituitary–adrenal axis secretion and the postprandial rise in plasma glucose were blunted by oxytocin in both groups. Conclusions: Oxytocin exerts an acutely inhibitory impact on food intake that is enhanced rather than decreased in obese compared with normal-weight men. This pattern puts it in contrast to other metabolically active neuropeptides and bodes well for clinical applications of oxytocin in the treatment of metabolic disorders.

The period from conception to 24 months of age is a crucial window for nutrition interventions. Personalized maternal counseling may improve childbirth outcomes, growth, and health. We assessed the effectiveness of facility-based personalized maternal nutrition counseling (from pregnancy to 18 months after birth) in improving child growth and health in rural Burkina Faso. We conducted a paired cluster randomized controlled trial in a rural district of Burkina Faso with 12 primary health centers (clusters). Healthcare providers in the intervention centers received patient-centered communication and nutrition counseling training. Pregnant women in the third trimester living in the center catchment areas and intending to stay for the next 2 years were prospectively included. We followed 2253 mother-child pairs quarterly until the child was aged 18 months. Women were interviewed about counseling experiences, dietary practices during pregnancy, and their child's feeding practices and morbidity history. Anthropometric measurements were taken at each visit using standardized methods. The primary outcomes were the cumulative incidence of wasting, and changes in child weight-for-height z-score (WHZ). Secondary outcomes were the women's prenatal dietary practices, early breastfeeding practices, exclusive breastfeeding, timely introduction of complementary food, child's feeding frequency and dietary diversity, children's mean birth weight, endpoint prevalence of stunting, and cumulative incidence of diarrhea, fever, and acute respiratory infection. All analyses were by intention-to-treat using mixed effects models. The intervention and control arms each included six health centers. Mothers in the intervention arm had a significantly higher exposure to counseling with 11.2% for breastfeeding techniques to 75.7% for counseling on exclusive breastfeeding. Mothers of infants below 6 months of age in the intervention arm were more likely to exclusively breastfeed (54.3% vs 42.3%; Difference of Proportion (DP) 12.8%; 95% CI: 2.1, 23.6; p = 0.020) as compared to the control arm. Between 6 and 18 months of age, more children in the intervention arm benefited from the required feeding frequency (68.8% vs 53.4%; DP 14.1%; 95% CI: 9.0, 19.2; p<0.001) and a larger proportion had a minimum dietary diversity (28.6% vs 22.0%; DP 5.9%; 95% CI: 2.7, 9.2; p<0.001). Birth weight of newborns in the intervention arm was on average 84.8 g (p = 0.037) larger compared to the control arm. However, we found no significant differences in child anthropometry or morbidity between study arms. Facility-based personalized maternal nutrition counseling was associated with an improved prenatal dietary practices, Infant and Young Child Feeding practices, and child birth weight. Complementary strategies are warranted to obtain meaningful impact on child growth and morbidity. This includes strategies to ensure good coverage of facility-based services and effective nutrition/care practices in early childhood.

BackgroundSome weight loss medications, including liraglutide 3.0 mg, are thought to facilitate weight loss by improving appetite control. However, no studies have evaluated their long-term appetitive effects.Subjects/methodsThis study examined changes in appetite in a subsample of 113 adults with obesity (76.1% female, 55.8% white, BMI = 38.8 ± 4.8 kg/m2) who participated in a 52-week trial. Participants were randomized to intensive behavioral therapy alone (IBT-alone), IBT with liraglutide 3.0 mg/day (IBT-liraglutide), or IBT-liraglutide combined with a 12-week meal replacement diet (Multi-component). Participants rated their hunger, fullness after meals, liking of meals, and food preoccupation (all as experienced over the past week) using visual analogue scales (0–100 mm). Ratings were completed at baseline and eight subsequent visits over the year.ResultsAt week 52, participants treated by IBT-alone lost 6.2 ± 1.6% of baseline weight, compared with 11.8 ± 1.6% and 12.1 ± 1.5% in the IBT-liraglutide and Multi-component groups, respectively. Compared to IBT-alone, IBT-liraglutide participants reported larger reductions at week 6 in hunger (−0.3 ± 4.2 vs −16.8 ± 4.0 mm, p = .005) and food preoccupation (+0.2 ± 3.7 vs −16.3 ± 3.6 mm, p = .002) and larger increases in fullness (−5.1 ± 3.2 vs +9.8 ± 3.0 mm, p = .001). These significant differences persisted at all assessments through week 24. There were no differences between IBT-alone and IBT-liraglutide in meal liking. IBT-alone and Multi-component participants differed in hunger at week 6, and in food preoccupation at all assessments through week 24. Multi-component participants reported reduced liking of meals relative to the IBT-alone and IBT-liraglutide groups through weeks 40 and 52, respectively. There were no other differences among any groups at week 52.ConclusionsConsistent with short-term studies, IBT-liraglutide participants reported greater improvements in hunger, fullness, and food preoccupation than those assigned to IBT-alone. Differences in appetite persisted for 24 weeks but were not maintained at week 52, despite the relatively greater weight losses in the liraglutide-treated participants at the trial’s end.