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Appetite Feb 2011Dietary fibres have many functions in the diet, one of which may be to promote control of energy intake and reduce the risk of developing obesity. This is linked to the... (Review)
Review
Dietary fibres have many functions in the diet, one of which may be to promote control of energy intake and reduce the risk of developing obesity. This is linked to the unique physico-chemical properties of dietary fibres which aid early signalling of satiation and prolonged or enhanced sensation of satiety. Particularly the ability of some dietary fibres to increase viscosity of intestinal contents offers numerous opportunities to affect appetite regulation. Few papers on the satiating effect of dietary fibres include information on the physico-chemical characteristics of the dietary fibres being tested, including molecular weight and viscosity. For viscosity to serve as a proxy for soluble dietary fibres it is essential to have an understanding of individual dietary fibre viscosity characteristics. The goal of this paper is to provide a brief overview on the role of dietary fibres in appetite regulation highlighting the importance of viscosity.
Topics: Appetite Regulation; Dietary Fiber; Energy Intake; Humans; Intestines; Obesity; Satiation; Viscosity
PubMed: 21115081
DOI: 10.1016/j.appet.2010.11.147 -
Journal of Neuroendocrinology Dec 2012Glucagon-like peptide-1 receptor (GLP-1R) agonists such as exendin-4 (Ex-4) affect eating and metabolism and are potential candidates for treating obesity and type II...
Glucagon-like peptide-1 receptor (GLP-1R) agonists such as exendin-4 (Ex-4) affect eating and metabolism and are potential candidates for treating obesity and type II diabetes. In the present study, we tested whether vagal afferents mediate the eating-inhibitory and avoidance-inducing effects of Ex-4. Subdiaphragmatic vagal deafferentation (SDA) blunted the short-term (< 1 h) but not long-term eating-inhibitory effect of i.p.-infused Ex-4 (0.1 μg/kg) in rats. A dose of 1 μg/kg Ex-4 reduced 0.5, 1, 2 and 4 h cumulative food intake in SDA and sham-operated rats to a similar extent. Paradoxically, SDA but not sham rats developed a conditioned flavour avoidance (CFA) after i.p. Ex-4 (0.1 μg/kg). SDA completely blunted the induction of c-Fos expression by Ex-4 in the hypothalamic paraventricular nucleus. Ex-4, however, increased the number of c-Fos expressing cells, independent of intact vagal afferents, in the nucleus accumbens and in the central nucleus of the amygdala, the lateral external parabrachial nucleus, the caudal ventrolateral medulla and the dorsal vagal complex. These data suggest that intact vagal afferents are only necessary for the full expression of the early satiating effect of Ex-4 but not for later eating-inhibitory actions, when circulating Ex-4 might reach the brain via the circulation. Our data also dissociate the satiating and avoidance-inducing effects of the low Ex-4 dose tested under our conditions and suggest that vagal afferent signalling may protect against the development of CFA. Taken together, these findings reveal a complex role of vagal afferents in mediating the effects of GLP-1R activation on ingestive behaviour.
Topics: Afferent Pathways; Animals; Avoidance Learning; Brain; Drug Evaluation, Preclinical; Eating; Exenatide; Feeding Behavior; Hypoglycemic Agents; Infusions, Parenteral; Male; Peptides; Rats; Rats, Sprague-Dawley; Satiation; Taste; Vagus Nerve; Venoms
PubMed: 22827554
DOI: 10.1111/j.1365-2826.2012.02364.x -
Nature Reviews. Endocrinology May 2010This Perspective focuses on two elements of our food supply and eating environment that facilitate high energy intake: a high eating rate and distraction of attention... (Review)
Review
This Perspective focuses on two elements of our food supply and eating environment that facilitate high energy intake: a high eating rate and distraction of attention from eating. These two elements are believed to undermine our body's capacity to regulate its energy intake at healthy levels because they impair the congruent association between sensory signals and metabolic consequences. The findings of a number of studies show that foods that can be eaten quickly lead to high food intake and low satiating effects-the reason being that these foods only provide brief periods of sensory exposure, which give the human body insufficient cues for satiation. Future research should focus on the underlying physiological, neurological and molecular mechanisms through which our current eating environment affects our control of food intake.
Topics: Attention; Energy Intake; Energy Metabolism; Environment; Fast Foods; Feeding Behavior; Humans; Satiation; Sensation
PubMed: 20351697
DOI: 10.1038/nrendo.2010.41 -
Nutrition Reviews Aug 2015Recent data support the idea that regular yogurt consumption promotes body weight stability. The simplest explanation is that regular consumption of healthful foods such... (Review)
Review
Recent data support the idea that regular yogurt consumption promotes body weight stability. The simplest explanation is that regular consumption of healthful foods such as yogurt results in decreased intake of less healthful foods containing high amounts of fat and/or sugar. There is also evidence to suggest that the high calcium and protein contents of yogurt and other dairy foods influence appetite and energy intake. The existence of a calcium-specific appetite control mechanism has been proposed. Milk proteins differ in terms of absorption rate and post-absorptive responses, which can influence their satiating properties. Studies in humans have shown that consumption of milk and yogurt increases the circulating concentration of the anorectic peptides glucagon-like peptide (GLP)-1 and peptide YY (PYY). The food matrix can also affect appetite and satiety. Yogurt is a fermented milk that contains bacteria that enrich the microbiota of the host. It appears that lean vs obese humans differ in the composition of their gut microbiota. The available relevant literature suggests that yogurt is a food that facilitates the regulation of energy balance.
Topics: Appetite; Appetite Regulation; Body Composition; Energy Intake; Energy Metabolism; Humans; Obesity; Satiation; Yogurt
PubMed: 26175486
DOI: 10.1093/nutrit/nuv015 -
Physiology & Behavior Jul 2009Much of the research in ingestive behavior has focused on the macronutrient composition of foods; however, these studies are incomplete, or could be misleading, if they... (Review)
Review
Much of the research in ingestive behavior has focused on the macronutrient composition of foods; however, these studies are incomplete, or could be misleading, if they do not consider the energy density (ED) of the diet under investigation. Lowering the ED (kcal/g) by increasing the volume of preloads without changing macronutrient content can enhance satiety and reduce subsequent energy intake at a meal. Ad libitum intake or satiation has also been shown to be influenced by ED when the proportions of macronutrients are constant. Since people tend to eat a consistent weight of food, when the ED of the available foods is reduced, energy intake is reduced. The effects of ED have been seen in adults of different weight status, sex, and behavioral characteristics, as well as in 3- to 5-year-old children. The mechanisms underlying the response to variations in ED are not yet well understood and data from controlled studies lasting more than several days are limited. However, both population-based studies and long-term clinical trials indicate that the effects of dietary ED can be persistent. Several clinical trials have shown that reducing the ED of the diet by the addition of water-rich foods such as fruits and vegetables was associated with substantial weight loss even when patients were not told to restrict calories. Since lowering dietary energy density could provide effective strategies for the prevention and treatment of obesity, there is a need for more studies of mechanisms underlying the effect and ways to apply these findings.
Topics: Animals; Diet; Energy Intake; Humans; Satiation
PubMed: 19303887
DOI: 10.1016/j.physbeh.2009.03.011 -
Neurogastroenterology and Motility Nov 2016Synthetic human ghrelin accelerates gastric emptying, reduces gastric accommodation, and results in numerical increases in postprandial symptom scores. The ghrelin... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Synthetic human ghrelin accelerates gastric emptying, reduces gastric accommodation, and results in numerical increases in postprandial symptom scores. The ghrelin receptor agonist, relamorelin, accelerates gastric emptying in patients with diabetic gastroparesis.
AIM
To measure pharmacological effects of relamorelin on gastric accommodation, distal antral motility, and satiation in healthy volunteers.
METHODS
In a placebo-controlled, double-blind, randomized study of 16 healthy volunteers, we compared effects of 30 μg subcutaneous (s.c.) relamorelin to placebo on: (i) gastric volumes measured by single photon emission computed tomography, (ii) 1-h postprandial distal antral motility index (MI) by 15-lumen perfusion gastroduodenal manometry, and (iii) satiation tested by Ensure nutrient drink test. Primary endpoints were: fasting and postprandial gastric volumes, distal antral phasic pressure activity (number of contractions, mean amplitude, and MI), and maximum tolerated volume. Results were normally distributed and the two treatment groups were compared using t-test.
KEY RESULTS
Relamorelin, 30 μg s.c., significantly increased the number of contractions in the distal antrum during 0-60 min postmeal when compared to placebo (p = 0.022); this was also observed in the first two 15-min periods (p = 0.005 and 0.015 for number of contractions 0-15 and 16-30). There was borderline increase in MI (p = 0.055) and numerically increased MI (p = 0.139) and MI (p = 0.116). The amplitude of contractions was not significantly increased. Relamorelin did not significantly alter fasting or postprandial gastric volumes, gastric accommodation, or satiation volumes and symptoms.
CONCLUSIONS & INFERENCES
Relamorelin increases frequency of distal antral motility contractions without significant effects on amplitude of contractions. The lack of inhibition of accommodation and absence of increase in satiation symptoms support relamorelin for the treatment of symptomatic gastroparesis (ClinicalTrials.gov NCT02466711).
Topics: Adult; Double-Blind Method; Female; Healthy Volunteers; Humans; Male; Manometry; Oligopeptides; Pyloric Antrum; Receptors, Ghrelin; Satiation
PubMed: 27283792
DOI: 10.1111/nmo.12870 -
The American Journal of Physiology Jul 1999When rats are maintained on high-fat diets, digestive processes adapt to provide for more efficient digestion and absorption of this nutrient. Furthermore, rats fed...
When rats are maintained on high-fat diets, digestive processes adapt to provide for more efficient digestion and absorption of this nutrient. Furthermore, rats fed high-fat diets tend to consume more calories and gain more weight than rats on a low-fat diet. We hypothesized that, in addition to adaptation of digestive processes, high-fat maintenance diets might result in reduction of sensitivity to the satiating effects of fat digestion products, which inhibit food intake by activating sensory fibers in the small intestine. To test this hypothesis we measured food intake after intestinal infusion of oleic acid or the oligosaccharide maltotriose in rats maintained on a low-fat diet or one of three high-fat diets. We found that rats fed high-fat diets exhibited diminished sensitivity to satiation by intestinal infusion of oleic acid. Sensitivity to the satiation effect of intestinal maltotriose infusion did not differ between groups maintained on the various diets. Reduced sensitivity to oleate infusion was specifically dependent on fat content of the diet and was not influenced by the dietary fiber or carbohydrate content. These results indicate that diets high in fat reduce the ability of fat to inhibit further food intake. Such changes in sensitivity to intestinal fats might contribute to the increased food intake and obesity that occur with high-fat diet regimens.
Topics: Adaptation, Physiological; Animals; Dietary Fats; Duodenum; Eating; Enteral Nutrition; Male; Oleic Acid; Rats; Rats, Sprague-Dawley; Satiety Response; Trisaccharides
PubMed: 10409283
DOI: 10.1152/ajpregu.1999.277.1.R279 -
Behavioural Brain Research Mar 2015Although decision making is a ubiquitous function, the understanding of its underlying mechanisms remains limited, particularly at the single-cell level. In this study,...
Although decision making is a ubiquitous function, the understanding of its underlying mechanisms remains limited, particularly at the single-cell level. In this study, we used the decision not to feed that follows satiation in the marine mollusk Aplysia to examine the role of putative decision-making neuron B51 in this process. B51 is a neuron in the feeding neural circuit that exhibits decision-making characteristics in vitro, which bias the circuit toward producing the motor programs responsible for biting behavior. Once satiated, Aplysia decided not to bite for a prolonged period of time (≥24h) when presented with a food stimulus that normally elicits feeding in non-satiated animals. Twenty-four hours after satiation, suppressed feeding was accompanied by a significant decrease of B51 excitability compared to the control group of unfed animals. No differences were measured in B51 resting membrane properties or synaptic input to B51 between the satiated and control groups. When B51 properties were measured at a time point in which feeding had recovered from the suppressive effects of satiation (i.e., 96 h after satiation), no difference in B51 excitability was observed between satiated and control groups. These findings indicate that B51 excitability changes in a manner that is coherent with the modifications in biting resulting from food satiation, thus implicating this neuron as a site of plasticity underlying the decision not to bite following food satiation in Aplysia.
Topics: Animals; Aplysia; Bites and Stings; Decision Making; Excitatory Postsynaptic Potentials; Feeding Behavior; Neurons; Satiation; Time Factors
PubMed: 25527117
DOI: 10.1016/j.bbr.2014.12.022 -
Appetite Jan 2013The modern food supply is often dominated by a large variety of energy dense, softly textured foods that can be eaten quickly. Previous studies suggest that particular... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
The modern food supply is often dominated by a large variety of energy dense, softly textured foods that can be eaten quickly. Previous studies suggest that particular oral processing characteristics such as large bite size and lack of chewing activity contribute to the low satiating efficiency of these foods. To better design meals that promote greater feelings of satiation, we need an accurate picture of the oral processing characteristics of a range of solid food items that could be used to replace softer textures during a normal hot meal.
AIM
The primary aim of this study was to establish an accurate picture of the oral processing characteristics of a set of solid savoury meal components. The secondary aim was to determine the associations between oral processing characteristics, food composition, sensory properties, and expected satiation.
METHODS
In a within subjects design, 15 subjects consumed 50 g of 35 different savoury food items over 5 sessions. The 35 foods represented various staples, vegetables and protein rich foods such a meat and fish. Subjects were video-recorded during consumption and measures included observed number of bites, number of chews, number of swallows and derived measures such as chewing rate, eating rate, bite size, and oral exposure time. Subjects rated expected satiation for a standard 200 g portion of each food using a 100mm and the sensory differences between foods were quantified using descriptive analysis with a trained sensory panel. Statistical analysis focussed on the oral processing characteristics and associations between nutritional, sensory and expected satiation parameters of each food.
RESULTS
Average number of chews for 50 g of food varied from 27 for mashed potatoes to 488 for tortilla chips. Oral exposure time was highly correlated with the total number of chews, and varied from 27 s for canned tomatoes to 350 s for tortilla chips. Chewing rate was relatively constant with an overall average chewing rate of approximately 1 chew/s. Differences in oral processing were not correlated with any macronutrients specifically. Expected satiation was positively related to protein and the sensory attributes chewiness and saltiness. Foods that consumed in smaller bites, were chewed more and for longer and expected to impart a higher satiation.
DISCUSSION
This study shows a large and reliable variation in oral exposure time, number of required chews before swallowing and expected satiation across a wide variety of foods. We conclude that bite size and oral-sensory exposure time could contribute to higher satiation within a meal for equal calories.
Topics: Adolescent; Adult; Eating; Energy Intake; Feeding Behavior; Female; Food; Food Preferences; Humans; Male; Mastication; Meals; Middle Aged; Satiation; Surveys and Questionnaires; Taste; Young Adult
PubMed: 23017464
DOI: 10.1016/j.appet.2012.09.015 -
Life Sciences Sep 1977
Clinical Trial Randomized Controlled Trial
Topics: Cholecystokinin; Dose-Response Relationship, Drug; Humans; Injections, Intravenous; Injections, Subcutaneous; Satiation; Satiety Response
PubMed: 916798
DOI: 10.1016/0024-3205(77)90403-9