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Appetite Oct 2023Older adults are advised to increase their protein intake to maintain their muscle mass. However, protein is considered the most satiating macronutrient and this... (Randomized Controlled Trial)
Randomized Controlled Trial
Older adults are advised to increase their protein intake to maintain their muscle mass. However, protein is considered the most satiating macronutrient and this recommendation may cause a decrease in total energy intake. To date, satiety studies comparing all three macronutrients have been undertaken in young adults, and it is unclear if the same response is seen in older adults. The objective of this study was to compare the effect of preloads high in protein, fat, and carbohydrate but equal in energy (∼300 kcal) and volume (250 ml) on energy intake, perceived appetite, and gastric emptying in younger and older adults. Twenty older and 20 younger adults completed a single-blinded randomised crossover trial involving three study visits. Participants consumed a standard breakfast, followed by a preload milkshake high in either carbohydrate, fat, or protein. Three hours after the preload, participants were offered an ad libitum meal to assess food intake. Visual analogue scales were used to measure perceived appetite and gastric emptying was measured via the C-octanoic acid breath test. There was no significant effect of preload type or age on energy intake either at the ad libitum meal, self-recorded food intake for the rest of the test day or subjective appetite ratings. There was a significant effect of preload type on gastric emptying latency phase and ascension time, and an effect of age on gastric emptying latency and lag phase such that older adults had faster emptying. In conclusion, energy intake, and perceived appetite were not affected by macronutrient content of the preloads in both younger and older adults, but gastric emptying times differed.
Topics: Young Adult; Humans; Aged; Satiation; Appetite; Energy Intake; Nutrients; Eating; Carbohydrates; Cross-Over Studies
PubMed: 37507052
DOI: 10.1016/j.appet.2023.106982 -
Obesity Reviews : An Official Journal... Feb 2018Fatty acid ethanolamides are lipid mediators that regulate a plethora of physiological functions. One such bioactive lipid mediator, oleoylethanolamide (OEA), is a... (Review)
Review
Fatty acid ethanolamides are lipid mediators that regulate a plethora of physiological functions. One such bioactive lipid mediator, oleoylethanolamide (OEA), is a potent agonist of the peroxisome proliferator-activated receptor-alpha (PPAR-α), which modulates increased expression of the fatty acid translocase CD36 that enables the regulation of feeding behaviour. Consumption of dietary fat rich in oleic acid activates taste receptors in the gut activating specific enzymes that lead to the formation of OEA. OEA further combines with PPAR-α to enable fat oxidation in the liver, resulting in enhanced energy production. Evidence suggests that sustained ingestion of a high-fat diet abolishes the anorexic signal of OEA. Additionally, malfunction of the enterocyte that transforms oleic acid produced during fat digestion into OEA might be responsible for reduced satiety and hyperphagia, resulting in overweight and obesity. Thus, OEA anorectic signalling may be an essential element of the physiology and metabolic system regulating dietary fat intake and obesity. The evidence reviewed in this article indicates that intake of oleic acid, and thereby the resulting OEA imparting anorexic properties, is dependent on CD36, PPAR-α, enterocyte fat sensory receptors, histamine, oxytocin and dopamine; leading to increased fat oxidation and enhanced energy expenditure to induce satiety and increase feeding latency; and that a disruption in any of these systems will cease/curb fat-induced satiety.
Topics: Diet, High-Fat; Endocannabinoids; Feeding Behavior; Gene Expression Regulation; Gene Targeting; Humans; Oleic Acids; PPAR alpha; Satiation
PubMed: 29124885
DOI: 10.1111/obr.12630 -
Physiology & Behavior Nov 2011Obesity develops despite a complex and seemingly well orchestrated network that controls eating, energy expenditure and ultimately body weight; many of the involved... (Review)
Review
Obesity develops despite a complex and seemingly well orchestrated network that controls eating, energy expenditure and ultimately body weight; many of the involved signals are derived from the gastrointestinal tract. It is assumed that this network as an entity aims at maintaining body weight and body adiposity at a relatively constant level, but the control mechanisms seem to fail at least if an individual is chronically exposed to an oversupply of food. This article summarizes recent findings about the role of amylin in the control of eating in lean and obese rodents. The article gives some short background information about the well investigated adiposity and satiating signals leptin and cholecystokinin, respectively; this will provide the framework to discuss aspects of amylin physiology and pathophysiology in the control of eating in leanness and obesity. This discussion also involves the mechanisms mediating amylin's eating inhibitory effect in the area postrema and the interactions between amylin and leptin. Further, we discuss the effect of high fat diets on amylin release and amylin action in lean and obese rats. The last part of this article raises the question whether amylin interacts with the reward system in the forebrain.
Topics: Animals; Diet, High-Fat; Eating; Hypothalamus; Islet Amyloid Polypeptide; Neurons; Obesity; Rats; Satiation
PubMed: 21324327
DOI: 10.1016/j.physbeh.2011.02.015 -
Gastroenterology May 1994
Topics: Gastrin-Releasing Peptide; Humans; Peptides; Satiation
PubMed: 8174896
DOI: 10.1016/0016-5085(94)90032-9 -
Asia Pacific Journal of Clinical... 2008Several studies have shown that high protein meals and foods are more satiating than high carbohydrate or high fat meals when assessed by subjective ratings of satiety.... (Review)
Review
Several studies have shown that high protein meals and foods are more satiating than high carbohydrate or high fat meals when assessed by subjective ratings of satiety. Few of these studies were able to control for potentially confounding variables. Test meals differ widely in physical and sensory properties so it cannot be concluded that it is protein conferring these effects. When sensory properties are controlled up to 10-30% more calories are eaten at a subsequent meal with a high carbohydrate liquid meal than a high protein liquid meal with no difference in protein sources or BMI status. Weight loss studies examining the metabolic effects of isocaloric high protein energy restricted diets with high carbohydrate structured diets have not shown differences in kilojoule intake and weight loss despite expected satiety differences. Such studies do not allow the effects of increased satiety attributable to protein to be expressed as the dietary protocols have required all foods to be consumed. However, several longer term studies have noted improvements in body composition on a higher protein pattern despite similar weight loss. An interaction between protein intake and exercise on improved lean mass retention has also been observed. Studies comparing ad libitun high protein diets to high carbohydrate diets have usually shown greater weight loss on the high protein pattern and that enhanced satiety was the most important factor in the weight loss.
Topics: Body Weight; Dietary Proteins; Humans; Nutritional Physiological Phenomena; Obesity; Satiation; Weight Loss
PubMed: 18296329
DOI: No ID Found -
The Journal of Experimental Biology Sep 1993
Topics: Animals; Behavior, Animal; Feeding Behavior; Leeches; Satiation; Serotonin
PubMed: 8228782
DOI: 10.1242/jeb.182.1.265 -
Behavioural Brain Research May 2007Olfaction plays a fundamental role in feeding behavior, but changes in olfactory acuity according to feeding states have never been precisely demonstrated in animals....
Olfaction plays a fundamental role in feeding behavior, but changes in olfactory acuity according to feeding states have never been precisely demonstrated in animals. The present study assesses the olfactory detection performance of fasted or satiated rats placed under a strictly controlled food-intake regimen. We did this using a conditioned odor aversion (COA) protocol which induced in rats an almost total aversion to an ISO-odorized drink at 10(-5) (1 microl in 100 ml of water). The rats (either fasted or satiated) were then presented with different concentrations of ISO-odorized water to compare their ability to detect and so avoid the ISO drink. In both states, the rats consumed significantly larger volumes of ISO at 10(-10), 10(-9) and 10(-8) than at 10(-5), suggesting lower detection at these three concentrations, although the fasted rats consumed significantly less ISO drink than did the satiated ones, showing better ISO detection at these concentrations. These experiments provide original data demonstrating the expected fact that olfactory sensitivity increases in fasted animals. Since these results were obtained using a neutral odor, we suggest that olfactory acuity increases during fasting, enabling animals to more easily detect both food and environmental odors such as those of predators. This would have an obvious eco-ethological role by increasing the relevance of olfactory inputs when seeking food.
Topics: Animals; Appetite Regulation; Avoidance Learning; Fasting; Male; Nutritional Status; Rats; Rats, Wistar; Satiation; Sensory Thresholds; Signal Detection, Psychological; Smell; Statistics, Nonparametric
PubMed: 17367877
DOI: 10.1016/j.bbr.2007.02.012 -
Physiology & Behavior Jun 2009Prior to the introduction of sham feeding as a method for studying the controls of meal size, the dominant view was that gustatory stimulation activated the ingestion of... (Review)
Review
Prior to the introduction of sham feeding as a method for studying the controls of meal size, the dominant view was that gustatory stimulation activated the ingestion of palatable diets and postingestional stimulation inhibited it. Early sham feeding studies with rats challenged this view because they showed that, contrary to expectation, rats did not eat continuously the first time they were given a sham feeding test. They ate a larger meal than when tested under normal conditions but stopped eating and showed all the signs of satiety soon after. Only after two or more sham feeding tests did they eat continuously. Subsequent research, reviewed here, established that experience ingesting a diet under real feeding conditions leads to the development of a classically conditioned form of satiation based on an association between gustatory stimulation and some consequence of gastrointestinal stimulation by the ingested food. This conditioned orosensory satiating effect extinguishes when sham feeding occurs repeatedly without intervening real feeding tests. Thus gustatory stimulation both stimulates and inhibits meal size. An experimental implication of this finding is that intake during sham feeding must be shown to be maximal before sham feeding can be used to measure only the orosensory stimulation of the diet. Another implication is that the analysis of a change in meal size produced by some treatment should now include measurement of the potency of the conditioned orosensory satiating effect as well as the potencies of orosensory stimulation and postingestive negative feedback.
Topics: Animals; Conditioning, Psychological; Eating; Food Preferences; Humans; Satiety Response; Sensation; Stimulation, Chemical; Taste
PubMed: 19358860
DOI: 10.1016/j.physbeh.2009.03.028 -
Peptides Apr 2014Reduction of food intake by exogenous cholecystokinin (CCK) has been demonstrated primarily for its short molecular form, CCK-8. Mounting evidence, however, implicates...
Reduction of food intake by exogenous cholecystokinin (CCK) has been demonstrated primarily for its short molecular form, CCK-8. Mounting evidence, however, implicates CCK-58 as a major physiologically active CCK form, with different neural and exocrine response profiles than CCK-8. In three studies, we compared meal-pattern effects of intraperitoneal injections CCK-8 vs. CCK-58 in undeprived male Sprague-Dawley rats consuming sweetened condensed milk. In study 1, rats (N=10) received CCK-8, CCK-58 (0.45, 0.9, 1.8 and 3.6 nmol/kg) or vehicle before a 4-h test-food presentation. At most doses, both CCK-8 and CCK-58 similarly reduced meal size relative to vehicle. Meal-size reduction prompted a compensatory shortening of the intermeal interval (IMI) after CCK-8, but not after CCK-58, which uniquely increased the satiety ratio (IMI/size of the preceding meal). In the second study, lick patterns were monitored after administration of 0.9 nmol/kg CCK-58, CCK-8 or vehicle. Lick cluster size, lick efficiency and interlick-interval distribution remained unaltered compared to vehicle, implying natural satiation, rather than illness, following both CCK forms. In study 3, threshold satiating doses of the two CCK forms were given at 5 and 30 min after meal termination, respectively. CCK 58, but not CCK-8 increased the intermeal interval and satiety ratio compared to vehicle. In conclusion, while CCK 58 and CCK-8 both stimulate satiation, thereby reducing meal size, CCK-58 consistently exerts a satiety effect, prolonging IMI. Given the physiological prominence of CCK-58, these results suggest that CCK's role in food intake regulation may require re-examination.
Topics: Animals; Cholecystokinin; Dose-Response Relationship, Drug; Male; Meals; Peptide Fragments; Rats, Sprague-Dawley; Satiation; Satiety Response
PubMed: 24468546
DOI: 10.1016/j.peptides.2014.01.008 -
Andrology May 2014The studies of sexual satiety in male rats under the Coolidge effect indicate that males reassume copulation until ejaculation. Recently, it was demonstrated that...
The studies of sexual satiety in male rats under the Coolidge effect indicate that males reassume copulation until ejaculation. Recently, it was demonstrated that sexually satiated males preserve the motor patterns of intromission and ejaculation, also penile erection, but not seminal expulsion. The first aim was to investigate if penile erections displayed by sexually satiated males dislodge the seminal plugs from the vagina and its effect on sperm transcervical transport. The second aim was to determine the recovery time of seminal expulsion after sexual satiety and its optimal ability to induce pregnancy. Results show that during the Coolidge effect males were able to dislodge the seminal plugs deposited by others (experiment 1A) disturbing the sperm transport (experiment 1B) then interfering with pregnancy (experiment 1C). After satiation, the ejaculate parameters recover slowly: it starts after 10 days with the seminal plug formation, and continues with an increase in sperm count in the uterus 15 days post-satiety (experiment 2). Sexually satiated males impregnated only 28% of the females during 15 days of cohabitation, whereas, satiated males that rested for 15 days impregnated 89% of the females (experiment 3). We concluded that males with successive ejaculations remain potential rivals, because they may disrupt the sperm transport of other males. The ejaculate features recovery after sexual satiety is gradual, begins with the secretions of the sex accessory glands and is followed by the sperm count. Full fertility recovery is reached after 15 days of sexual abstinence when males are able to impregnate most females.
Topics: Animals; Copulation; Ejaculation; Female; Male; Penile Erection; Rats; Rats, Wistar; Recovery of Function; Satiation; Semen; Sperm Count; Sperm Transport
PubMed: 24677685
DOI: 10.1111/j.2047-2927.2014.00209.x