Effects of glucose, propionate and splanchnic hormones on neuropeptide mRNA concentrations in the ovine hypothalamus

The capacity for glucose, propionate or hormones of splanchnic origin to influence appetite by directly regulating the expression of neuropeptides in the feeding centres of the hypothalamus of the ruminant is not described. Therefore, our objective was to measure the direct effect of metabolites (glucose and propionate) or hormones [insulin, cholecystokinin (CCK), glucagon-like peptide-1 (GLP-1) and polypeptide YY (PYY)] on hypothalamic mRNA concentrations for neuropeptide Y (NPY), agouti-related peptide (AgRP) and proopiomelanocortin (POMC) following in vitro incubation. Hypothalamic tissue from 4- to 5-month-old lambs was obtained at slaughter and immediately incubated in culture media for 2 h at 36 °C. Treatments included a control Dulbecco’s modified Eagle medium (DMEM) containing 1 mm glucose or DMEM with the following additions: 10 mm glucose, 1 mm propionate, 1 nm insulin, 120 pm GLP-1, 100 pm PYY, 80 pm CCK or 10 mm glucose plus 1 nm insulin. The abundance of mRNA for NPY, AgRP and POMC was measured using quantitative reverse transcriptase PCR. Fisher’s protected LSD test was used to compare changes in relative mRNA concentrations for the hypothalamus incubated in the control media vs. the rest of the treatments. The media containing glucose plus insulin increased POMC mRNA concentration (p < 0.05), but did not affect NPY or AgRP mRNA concentration. There were no effects observed for the other treatments (p > 0.20). Results of the present study are consistent with the concept that effects of propionate on feed intake in ruminants is not mediated through direct effects on the hypothalamus, and that insulin is required for an effect of glucose on hypothalamic POMC expression.

Hospital catering systems and their impact on the sensorial profile of foods provided to older patients in the UK

Impaired sensorial perception is very common in older people and low sensorial quality of foods is associated with decreased appetite and dietary intake. Hospital undernutrition in older patients could be linked to sensorial quality of hospital food if the quality were low or inappropriate for older people. The aim of this study was to examine changes in the sensorial quality of different foods that occur as a result of the food journey (i.e. freezing, regeneration, etc.) in the most common hospital catering systems in the UK. A trained sensory panel assessed sensorial descriptors of certain foods with and without the hospital food journey as it occurs in the in-house and cook/freeze systems. The results showed effects of the food journey on a small number of sensorial descriptors related to flavour, appearance and mouthfeel. The majority of these effects were due to temperature changes, which caused accumulation of condensation. A daily variation in sensorial descriptors was also detected and in some cases it was greater than the effect of the food journey. This study has shown that changes occur in the sensory quality of meals due to hospital food journeys, however these changes were small and are not expected to substantially contribute to acceptability or have a major role in hospital malnutrition.

Non-D9-tetrahydrocannabinol phytocannabinoids stimulate feeding in rats

Cannabinoid type 1 receptor-mediated appetite stimulation by D9tetrahydrocannabinol (D9THC) is well understood. Recently, it has become apparent that non-D9THC phytocannabinoids could also alter feeding patterns. Here, we show definitively that non-D9THC phytocannabinoids stimulate feeding. Twelve male, Lister-Hooded rats were prefed to satiety prior to administration of a standardized cannabis extract or to either of two mixtures of pure phytocannabinoids (extract analogues) comprising the phytocannabinoids present in the same proportions as the standardized extract (one with and one without D9THC). Hourly intake and meal pattern data were recorded and analysed using two-way analysis of variance followed by one-way analysis of variance and Bonferroni post-hoc tests. Administration of both extract analogues significantly increased feeding behaviours over the period of the test. All three agents increased hour-one intake and meal-one size and decreased the latency to feed, although the zero-D9THC extract analogue did so to a lesser degree than the high-D9THC analogue. Furthermore, only the analogue containing D9THC significantly increased meal duration. The data confirm that at least one non-D9THC phytocannabinoid induces feeding pattern changes in rats, although further trials using individual phytocannabinoids are required to fully understand the observed effects.

Endocannabinoids, FOXO and the metabolic syndrome: redox, function and tipping point--the view from two systems

The endocannabinoid system (ECS) was only 'discovered' in the 1990s. Since then, many new ligands have been identified, as well as many new intracellular targets--ranging from the PPARs, to mitochondria, to lipid rafts. It was thought that blocking the CB-1 receptor might reverse obesity and the metabolic syndrome. This was based on the idea that the ECS was dysfunctional in these conditions. This has met with limited success. The reason may be that the ECS is a homeostatic system, which integrates energy seeking and storage behaviour with resistance to oxidative stress. It could be viewed as having thrifty actions. Thriftiness is an innate property of life, which is programmed to a set point by both environment and genetics, resulting in an epigenotype perfectly adapted to its environment. This thrifty set point can be modulated by hormetic stimuli, such as exercise, cold and plant micronutrients. We have proposed that the physiological and protective insulin resistance that underlies thriftiness encapsulates something called 'redox thriftiness', whereby insulin resistance is determined by the ability to resist oxidative stress. Modern man has removed most hormetic stimuli and replaced them with a calorific sedentary lifestyle, leading to increased risk of metabolic inflexibility. We suggest that there is a tipping point where lipotoxicity in adipose and hepatic cells induces mild inflammation, which switches thrifty insulin resistance to inflammation-driven insulin resistance. To understand this, we propose that the metabolic syndrome could be seen from the viewpoint of the ECS, the mitochondrion and the FOXO group of transcription factors. FOXO has many thrifty actions, including increasing insulin resistance and appetite, suppressing oxidative stress and shifting the organism towards using fatty acids. In concert with factors such as PGC-1, they also modify mitochondrial function and biogenesis. Hence, the ECS and FOXO may interact at many points; one of which may be via intracellular redox signalling. As cannabinoids have been shown to modulate reactive oxygen species production, it is possible that they can upregulate anti-oxidant defences. This suggests they may have an 'endohormetic' signalling function. The tipping point into the metabolic syndrome may be the result of a chronic lack of hormetic stimuli (in particular, physical activity), and thus, stimulus for PGC-1, with a resultant reduction in mitochondrial function and a reduced lipid capacitance. This, in the context of a positive calorie environment, will result in increased visceral adipose tissue volume, abnormal ectopic fat content and systemic inflammation. This would worsen the inflammatory-driven pathological insulin resistance and inability to deal with lipids. The resultant oxidative stress may therefore drive a compensatory anti-oxidative response epitomised by the ECS and FOXO. Thus, although blocking the ECS (e.g. via rimonabant) may induce temporary weight loss, it may compromise long-term stress resistance. Clues about how to modulate the system more safely are emerging from observations that some polyphenols, such as resveratrol and possibly, some phytocannabinoids, can modulate mitochondrial function and might improve resistance to a modern lifestyle.

Enhancing consumer liking of low salt tomato soup over repeated exposure by herb and spice seasonings

There is strong evidence for the link between high dietary sodium and increased risk of cardiovascular disease which drives the need to reduce salt content in foods. In this study, herb and spice blends were used to enhance consumer acceptability of a low salt tomato soup (0.26% w/w). Subjects (n=148) scored their liking of tomato soup samples over five consecutive days. The first and last days were pre-and post-exposure visits where all participants rated three tomato soup samples; standard, low salt and low salt with added herbs and spices. The middle 3 days were the repeated exposure phase where participants were divided into three balanced groups; consuming the standard soup, the low salt soup, or the low salt soup with added herbs and spices. Reducing salt in the tomato soup led to a significant decline in consumer acceptability, and incorporating herbs and spices did not lead to an immediate enhancement in liking. However, inclusion of herbs and spices enhanced the perception of the salty taste of the low salt soup to the same level as the standard. Repeated exposure to the herbs and spice-modified soup led to a significant increase in the overall liking and liking of flavour, texture and aftertaste of the soup, whereas no changes in liking were observed for the standard and low salt tomato soups over repeated exposure. Moreover, a positive trend in increasing the post-exposure liking of the herbs and spices soup was observed. The findings suggest that the use of herbs and spices is a useful approach to reduce salt content in foods; however, herbs and spices should be chosen carefully to complement the food as large contrasts in flavour can polarise consumer liking.

Impacts of plant-based foods in ancestral hominin diets on the metabolism and function of gut microbiota in vitro

Ancestral human populations had diets containing more indigestible plant material than present-day diets in industrialized countries. One hypothesis for the rise in prevalence of obesity is that physiological mechanisms for controlling appetite evolved to match a diet with plant fiber content higher than that of present-day diets. We investigated how diet affects gut microbiota and colon cells by comparing human microbial communities with those from a primate that has an extreme plant-based diet, namely, the gelada baboon, which is a grazer. The effects of potato (high starch) versus grass (high lignin and cellulose) diets on human-derived versus gelada-derived fecal communities were compared in vitro. We especially focused on the production of short-chain fatty acids, which are hypothesized to be key metabolites influencing appetite regulation pathways. The results confirmed that diet has a major effect on bacterial numbers, short-chain fatty acid production, and the release of hormones involved in appetite suppression. The potato diet yielded greater production of short-chain fatty acids and hormone release than the grass diet, even in the gelada cultures, which we had expected should be better adapted to the grass diet. The strong effects of diet on hormone release could not be explained, however, solely by short-chain fatty acid concentrations. Nuclear magnetic resonance spectroscopy found changes in additional metabolites, including betaine and isoleucine, that might play key roles in inhibiting and stimulating appetite suppression pathways. Our study results indicate that a broader array of metabolites might be involved in triggering gut hormone release in humans than previously thought. IMPORTANCE: One theory for rising levels of obesity in western populations is that the body's mechanisms for controlling appetite evolved to match ancestral diets with more low-energy plant foods. We investigated this idea by comparing the effects of diet on appetite suppression pathways via the use of gut bacterial communities from humans and gelada baboons, which are modern-day primates with an extreme diet of low-energy plant food, namely, grass. We found that diet does play a major role in affecting gut bacteria and the production of a hormone that suppresses appetite but not in the direction predicted by the ancestral diet hypothesis. Also, bacterial products were correlated with hormone release that were different from those normally thought to play this role. By comparing microbiota and diets outside the natural range for modern humans, we found a relationship between diet and appetite pathways that was more complex than previously hypothesized on the basis of more-controlled studies of the effects of single compounds.

Restrictive feeding practices and adiposity are differentially related to P3b cortical responses to food stimuli in children

Across two studies, we examined the association between adiposity, restrictive feeding practices and cortical processing bias to food stimuli in children. We assessed P3b event-related potential (ERP) during visual oddball tasks in which the frequently presented stimulus was non-food and the infrequently presented stimulus was either a food (Study 1) or non-food (Study 2) item. Children responded to the infrequently presented stimulus and accuracy and speed responses were collected. Restrictive feeding practices, children's height and weight were also measured. In Study 1, the difference in P3b amplitude for infrequently presented food stimuli, relative to frequently presented non-food stimuli, was negatively associated with adiposity and positively associated with restrictive feeding practices after controlling for adiposity. There was no association between P3b amplitude difference and adiposity or restriction in Study 2, suggesting that the effects seen in Study 1 were not due to general attentional processes. Taken together, our results suggest that attentional salience, as indexed by the P3b amplitude, may be important for understanding the neural correlates of adiposity and restrictive feeding practices in children.

Drug holidays from ADHD medication: international experience over the past four decades

Objective: ADHD is managed by stimulants that are effective but can cause growth retardation. Prescribers should ideally monitor children and trial a “drug holiday” to enable catch-up growth. Our aim was to map the experience of drug holidays from ADHD medication in children and adolescents. Method: A comprehensive search of the literature identified 22 studies published during the period 1972 to 2013. Results: Drug holidays are prevalent in 25% to 70% of families and are more likely to be exercised during school holidays. They test whether medication is still needed and are also considered for managing medication side effects and drug tolerance. The impact of drug holidays was reported in terms of side effects and ADHD symptoms. There was evidence of a positive impact on child growth with longer breaks from medication, and shorter breaks could reduce insomnia and improve appetite. Conclusion: Drug holidays from ADHD medication could be a useful tool with multiple purposes: assessment, management, prevention, and negotiation.

Exposure to foods’ non-taste sensory properties: a nursery intervention to increase children’s willingness to try fruit and vegetables

Activities that engage young children with the sensory properties of foods are popular with nursery schools, despite the lack of evidence for their efficacy in increasing children's consumption of healthy foods. This study provides the first empirical exploration of the effectiveness of a non-taste sensory activity program in a nursery school setting. Ninety-two children aged between 12 and 36 months were allocated to either an intervention group, who took part in looking, listening, feeling and smelling activities with unusual fruits and vegetables every day for four weeks, or to a non-intervention control group. In a subsequent mealtime taste test, children touched and tasted more of the vegetables to which they had been familiarized in their playtime activities than of a matched set of non-exposed foods. The results demonstrate that hands-on activities with unfamiliar fruits and vegetables can enhance children’s willingness to taste these foods, and confirm the potential for such activities to support healthy eating initiatives.

Potential anti-obesogenic properties of non-digestible carbohydrates: specific focus on resistant dextrin

Alterations in the composition and metabolic activity of the gut microbiota appear to contribute to the development of obesity and associated metabolic diseases. However, the extent of this relationship remains unknown. Modulating the gut microbiota with non-digestible carbohydrates (NDC) may exert anti-obesogenic effects through various metabolic pathways including changes to appetite regulation, glucose and lipid metabolism and inflammation. The NDC vary in physicochemical structure and this may govern their physical properties and fermentation by specific gut bacterial populations. Much research in this area has focused on established prebiotics, especially fructans (i.e. inulin and fructo-oligosaccharides); however, there is increasing interest in the metabolic effects of other NDC, such as resistant dextrin. Data presented in this review provide evidence from mechanistic and intervention studies that certain fermentable NDC, including resistant dextrin, are able to modulate the gut microbiota and may alter metabolic process associated with obesity, including appetite regulation, energy and lipid metabolism and inflammation. To confirm these effects and elucidate the responsible mechanisms, further well-controlled human intervention studies are required to investigate the impact of NDC on the composition and function of the gut microbiota and at the same time determine concomitant effects on host metabolism and physiology.

Novel flavours paired with glutamate condition increased intake in older adults in the absence of changes in liking

Previous research on the repeat exposure to a novel flavour combined with monosodium glutamate (MSG) has shown an increase in liking and consumption for the particular flavour. The aim of the current work was to investigate whether this could also be observed in the case of older people, since they are most affected by undernutrition in the developed world and ways to increase consumption of food are of significant importance for this particular age group. For this study, 40 older adults (age 65-88) repeatedly consumed potato soup with two novel flavours (lemongrass and cumin) which were either with or without a high level of MSG (5%w/w). A randomized single blind within-subject design was implemented, where each participant was exposed to both soup flavours three times over 6 days, with one of the soup flavours containing MSG. After three repeat exposures, consumption increased significantly for the soups where the flavours had contained MSG during the repeated exposure (mean weight consumed increased from 123 to 164 g, p=0.017), implying that glutamate conditioned for increased wanting and consumption, despite the fact that the liking for the soup had not increased.

Consumer purchasing behaviour towards fish and seafood products: patterns and insights from a sample of international studies

The present systematic review was performed to assess consumer purchasing behaviour towards fish and seafood products in the wide context of developed countries. Web of Science, Scopus, ScienceDirect and Google Scholar engines were used to search the existing literature and a total of 49 studies were identified for inclusion. These studies investigated consumer purchasing behaviour towards a variety of fish and seafood products, in different countries and by means of different methodological approaches. In particular, the review identifies and discusses the main drivers and barriers of fish consumption as well as consumers’ preferences about the most relevant attributes of fish and seafood products providing useful insights for both practitioners and policy makers. Finally, main gaps of the existing literature and possible trajectories for future research are also discussed.

Recent developments in prebiotics to selectively impact beneficial microbes and promote intestinal health

Prebiotics are non-digestible food ingredients that have a specific stimulatory effect upon selected populations of gut bacteria. The usual target microorganisms for prebiotic approaches are bifidobacteria. Numerous human feeding studies have shown the prebiotic influences that galactans and fructans can exert. Other candidate prebiotics are under investigation. The field is now moving towards identifying the health aspect associated with their use. Many avenues of gut related health are being researched, including reduction of diarrhoea, immune stimulation, and improved mineral bioavailability. Most current emphasis appears to be towards various parameters associated with metabolic syndrome. These include markers of insulin resistance, appetite, satiety, blood lipids and inflammatory status.

Factors influencing European consumer uptake of personalised nutrition: results of a qualitative analysis

The aim of this research was to explore consumer perceptions of personalised nutrition and to compare these across three different levels of ‘‘medicalization’’: lifestyle assessment (no blood sampling); phenotypic assessment (blood sampling); genomic assessment (blood and buccal sampling). The protocol was developed from two pilot focus groups conducted in the UK. Two focus groups (one comprising only ‘‘older’’ individuals between 30 and 60 years old, the other of adults 18–65 yrs of age) were run in the UK, Spain, the Netherlands, Poland, Portugal, Ireland, Greece and Germany (N = 16). The analysis (guided using grounded theory) suggested that personalised nutrition was perceived in terms of benefit to health and fitness and that convenience was an important driver of uptake. Negative attitudes were associated with internet delivery but not with personalised nutrition per se. Barriers to uptake were linked to broader technological issues associated with data protection, trust in regulator and service providers. Services that required a fee were expected to be of better quality and more secure. An efficacious, transparent and trustworthy regulatory framework for personalised nutrition is required to alleviate consumer concern. In addition, developing trust in service providers is important if such services to be successful.

Information and punitiveness: trial reconstruction in Ireland

Purpose – The purpose of this paper is to report results from a rape trial reconstruction in Ireland. Design/methodology/approach – A studio audience of 100 members of the Irish public were selected to attend a TV programme by the Republic of Ireland’s national broadcasting organisation. This involved the examination of the sentencing of a rape case. The audience’s sentencing preferences were measured at the outset, when they had been given only summary information about the case, and later, when full details had been disclosed. Findings – Previous research examining changes in public attitudes to crime and punishment has shown that deliberation, including the provision of new information and discussion with others and experts, tends to decrease public punitiveness and increase public leniency towards sentencing. An experiment in Ireland, however, showed that providing information does not invariably and necessarily moderate punitive attitudes. This paper presents the results, and offers some explanations for the anomalous outcome. Research limitations/implications – The pre/post design, in which the audience served as their own controls, is a weak one, and participants may have responded to what they took to be the agenda of the producers. Due to the quality of the sample, the results may not be generalisable to the broader Irish population. Practical implications – Policy makers should recognise that the public is not uniformly punitive for all crimes. There is good research evidence to show that the apparent public appetite for tough punishment is illusory, and is a function of the way that polls measure public attitudes to punishment. Sentencers and those responsible for sentencing policy would benefit from a fuller understanding of the sorts of cases which illicit strong punitive responses from the public, and the reasons for this response. However any such understanding should not simply translate into responsiveness to the public’s punitive sentiments – where these exist. Innovative survey methods – like this experiment – which attempt to look beyond the top-of-the-head opinions by providing information and opportunities for deliberation should be welcomed and used more widely. Originality/value – There have been limited research studies which reports factors which may increase punitiveness through the provision of information and deliberation.