scholarly journals The homeostatic dynamics of feeding behaviour identify novel mechanisms of anorectic agents

2019 ◽  
Author(s):  
Thomas M McGrath ◽  
Eleanor Spreckley ◽  
Aina Fernandez Rodriguez ◽  
Carlo Viscomi ◽  
Amin Alamshah ◽  
...  

AbstractBetter understanding of feeding behaviour will be vital in reducing obesity and metabolic syndrome, but we lack a standard model that captures the complexity of feeding behaviour. We construct an accurate stochastic model of rodent feeding at the bout level in order to perform quantitative behavioural analysis. Analysing the different effects on feeding behaviour of PYY3-36, lithium chloride, GLP-1 and leptin shows the precise behavioural changes caused by each anorectic agent. Our analysis demonstrates that the changes in feeding behaviour evoked by the anorectic agents investigated not mimic satiety. In thead libitumfed state during the light period, meal initiation is governed by complete stomach emptying, whereas in all other conditions there is a graduated response. We show how robust homeostatic control of feeding thwarts attempts to reduce food intake, and how this might be overcome.In silicoexperiments suggest that introducing a minimum intermeal interval or modulating gastric emptying can be as effective as anorectic drug administration.

1971 ◽  
Vol 28 (11) ◽  
pp. 1749-1755 ◽  
Author(s):  
H. T. Bilton ◽  
G. L. Robins

Young sockeye salmon (Oncorhynchus nerka) survived a starvation period of 20 weeks with no change in their mean length and weight and with no record of this starvation period on their scales. Fish offered an ad libitum diet for more than 4 weeks in the 20-week period had significant increases in body and scale growth. The number of checks on their scales was correlated with the number of weeks fish were offered an ad libitum diet and not with the number of weeks they were starved. Thus, a significant increase in food induced the formation of a check. Light period appeared to have some influence on body and scale growth.


2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Jess Gwin ◽  
Heather Leidy

Abstract Objectives The purpose of this study was to examine the acute effects of consuming isocaloric, higher-protein breakfast shakes varying in protein source on appetite, satiety, and subsequent breakfast and lunch food intake in healthy adults. Methods Thirty-two adults (Age: 25 ± 1y; BMI: 24.2 ± 0.5 kg/m2) randomly consumed 250 kcal higher-protein breakfast shakes (24 g total protein; 17 g CHO; 9 g fat), varying only in protein source (whey protein isolate, WHEY; soy protein isolate, SOY; Micellar Casein, CAS; pea protein isolate, PEA; and milk protein isolate; MILK) for 3 days/shake. On day 4, the participants completed a 4-h testing day that included the consumption of the respective shake followed by blood sampling and questionnaires taken every 30 min to assess appetite and satiety. At the end of the testing day, an ad libitum lunch was provided. In addition, we sought to assess whether the study shakes consumed as breakfast preloads reduce food intake within the breakfast eating occasion. Thus, on day 5, the respective shake was consumed 30 min before an ad libitum breakfast. Results Postprandial differences in morning fullness and desire to eat were detected between protein shakes. Specifically, MILK led to greater 4-h fullness vs. WHEY, SOY, and PEA (all, P < 0.05) but not vs. CAS. CAS led to greater fullness vs. SOY (P < 0.05). In addition, MILK, CAS, and PEA led to greater decreases in 4-h desire to eat vs. SOY (all, P < 0.05). No differences in hunger, prospective food consumption, or food cravings were detected. At the subsequent lunch meal, the participants consumed on average 750 ± 70 kcal with no differences observed between shakes. Lastly, regardless of the protein source within the preloads, the participants consumed an additional +280 ± 50 kcal from other breakfast foods. Blood sampling analyses of metabolic analytes and appetite hormones are on-going. Conclusions Although protein source differences within isocaloric, higher-protein breakfast shakes influenced appetite responses throughout the morning, subsequent breakfast and lunch intake was not modified. Funding Sources Leprino Foods.


2002 ◽  
Vol 74 (3) ◽  
pp. 517-528 ◽  
Author(s):  
C. McG. Argo ◽  
J. E. Cox ◽  
C. Lockyer ◽  
Z. Fuller

AbstractSeven, 3-year-old pony mares (~230 kg) were used in a cross-over study to compare the appetite, energy and nutrient digestibilities, growth rate and feeding behaviour, when a complete diet was offered ad libitum in either the original loose-chaff mix (C), or as a more convenient, milled and pelleted preparation (P). Ad libitum access to the study diet (gross energy = 17·2 MJ/kg dry matter (DM)) was attained over 2 weeks. In the following 4 weeks, groups 1 (no. = 3) and 2 (no. = 4) received pelleted and chaff-based diets respectively. Dietary forms were exchanged during week 5 and ad libitum provision continued for a further 4 weeks. Behaviour and apparent nutrient digestibilities were assessed in weeks 3 and 4 of each period. Pelleted food had a lower proportion of water (P, 0·12; C, 0·22), but relative proportions of oil (0·04), crude protein (0·08), crude fibre (0·29), neutral-detergent fibre (NDF; 0·53) and gross energy (GE) were neither altered by food processing nor time. Apparent digestibilities (DM, 0·49; GE, 0·50; NDF, 0·40 in period 1) of the pelleted and chaff-based diets were similar within periods but decreased (P 0·01) to a similar extent for both diet types (proportional changes: DM, –0·14; GE, –0·16; NDF, –0·28) in period 2. Overall, mean intakes of digestible energy (DE) for chaff-fed animals during period 1 were 0·73 (P 0·001) of pellet DE intake (DEI). Mean DEI of pellets increased (P 0·001) during period 1 to attain 1·76 (s.e. 0·25) MJ/kg M0·75 on day 25. Following transfer from pellets to chaff, DEI decreased (P 0·001) to 0·68 (s.e. 0·07) MJ/kg M0·75 by the end of period 2. In contrast, DEI of animals which progressed from chaff to pellets remained relatively constant between periods. Oestrous behaviour caused no detectable change in the appetite of individual mares. Irrespective of differences in DEI, average daily gain (ADG) in body weight and condition score (CS) did not differ between groups. Overall, mean ADG decreased (P 0·01) from 1·54 (s.e. 0·17) kg/day in period 1 to 0·26 (s.e.0·08) kg/day in period 2. Changes in body weight were associated with CS (R2 = 0·72). Each CS point represented a 53·4 (s.e. 4·8) kg gain in body weight. Chaff meals were longer (30·6 (s.e. 1·6) min, P 0·001), less frequent (23·8 (s.e. 1·4) per day, P 0·001) and associated with a lower bite rate (3·8 (s.e.0·2) per min, P 0·001) and increased chewing requirement (23 (s.e. 1·2) per bite, P 0·001), which decreased the rate of DM intake (17·0 (s.e. 0·9) g/min, P 0·0.01). Overall, chaff-fed animals spent more time feeding (0·50 (s.e. 1·3) of the time; P 0·0.01), primarily at the expense of non-feeding activity and rest. The ad libitum feeding regime enabled stabled ponies to re-establish natural feeding patterns and offers a viable alternative to meal and forage feeding. The more slowly ingested chaff form maximized time spent feeding and limited changes in DEI during the introductory period. Although CS and ADG increased over the first 4 weeks, growth and appetite returned to near maintenance values within 9 weeks in association with a decrease in dietary energy intake and nutrient digestibility.


2020 ◽  
Vol 61 (8) ◽  
pp. 1203-1220 ◽  
Author(s):  
Yan Q. Chen ◽  
Thomas G. Pottanat ◽  
Robert W. Siegel ◽  
Mariam Ehsani ◽  
Yue-Wei Qian ◽  
...  

Angiopoietin-like protein (ANGPTL)8 has been implicated in metabolic syndrome and reported to regulate adipose FA uptake through unknown mechanisms. Here, we studied how complex formation of ANGPTL8 with ANGPTL3 or ANGPTL4 varies with feeding to regulate LPL. In human serum, ANGPTL3/8 and ANGPTL4/8 complexes both increased postprandially, correlated negatively with HDL, and correlated positively with all other metabolic syndrome markers. ANGPTL3/8 also correlated positively with LDL-C and blocked LPL-facilitated hepatocyte VLDL-C uptake. LPL-inhibitory activity of ANGPTL3/8 was >100-fold more potent than that of ANGPTL3, and LPL-inhibitory activity of ANGPTL4/8 was >100-fold less potent than that of ANGPTL4. Quantitative analyses of inhibitory activities and competition experiments among the complexes suggested a model in which localized ANGPTL4/8 blocks the LPL-inhibitory activity of both circulating ANGPTL3/8 and localized ANGPTL4, allowing lipid sequestration into fat rather than muscle during the fed state. Supporting this model, insulin increased ANGPTL3/8 secretion from hepatocytes and ANGPTL4/8 secretion from adipocytes. These results suggest that low ANGPTL8 levels during fasting enable ANGPTL4-mediated LPL inhibition in fat tissue to minimize adipose FA uptake. During feeding, increased ANGPTL8 increases ANGPTL3 inhibition of LPL in muscle via circulating ANGPTL3/8, while decreasing ANGPTL4 inhibition of LPL in adipose tissue through localized ANGPTL4/8, thereby increasing FA uptake into adipose tissue. Excessive caloric intake may shift this system toward the latter conditions, possibly predisposing to metabolic syndrome.


2000 ◽  
Vol 71 (3) ◽  
pp. 571-575 ◽  
Author(s):  
N. Quiniou ◽  
D. Renaudeau ◽  
S. Dubois ◽  
J. Noblet

AbstractForty-two multiparous Large White sows were used to investigate the effect of diurnally fluctuating temperature (T) on lactation performance and feeding behaviour. The animals were allocated to one of the four thermic treatments: constant T at 25°C (25C) and 29°C (29C) or equal-mean diurnal cyclic T varying from 21 to 29°C (25V) and from 25 to 33°C (29V). Photoperiod was fixed to 14 h of light. The sows were given food ad libitum between the 7th and the 19th day post partům. Lactation performance was measured for all sows whereas the feeding behaviour was recorded only on 28 sows. The ad libitum food intake was comparable at 25C and 25V (6•31 kg/day) as were milk production and body reserves mobilization. In contrast, food intake at 29V was higher than at 29C (4•53 v. 3•48 kg/day) with no difference in milk production between the two treatments. The increased daily food intake at 29V resulted from higher intakes over the coolest periods of the day and especially during the dark period. Neither meal size nor daily number of meals were significantly affected by T. Feeding behaviour was mainly diurnal but with differences between treatments: 0•90 of total food intake at 29C v. 0•78 at the other three T It appears that the effects of diurnally fluctuating T on lactation performance of sows depend on the mean level of T


2002 ◽  
Vol 75 (1) ◽  
pp. 75-83 ◽  
Author(s):  
S.P. Turner ◽  
M. Dahlgren ◽  
D.S. Arey ◽  
S.A. Edwards

AbstractFeeder space allowance should be sufficient to ensure adequate access to food for all group members, irrespective of competitive ability. However, the influence of social group size on minimum feeder space requirement of pigs given food ad libitum is poorly understood. Performance, aggression and feeding behaviour were assessed over a 6-week period from 29·3 (s.e. 0·19) kg live weight, using four replicates of a 2 ✕ 2 factorial design with two group sizes (20 v. 80) (small and large) and two feeder space allowances (32·5 v. 42·5 mm per pig) (low and high). Food intake was significantly lower in the low feeder space allowance treatments (1·44 v. 1·56 (s.e.d. 0·050) kg per pig per day, P < 0·05) and group mean growth rate was reduced in the later phase between 41 and 56 kg live weight. There was no main effect of group size or interactive effect between group size and feeder space allowance on performance. Mean skin lesion score and the frequency of aggression given or received at the feeders was unaffected by treatment. Heavy weight pigs showed similar feeding behaviour in each treatment, but light pigs visited the feeder more frequently in groups of 20 (23·1 v. 16·0 (s.e.d. 2·04) visits per pig per day, P < 0·05) and spent the greatest time feeding when at a low feeder space allowance (5461 v. 4397 (s.e.d. 288·8) s per pig per day, P < 0·05). To avoid a depression in growth rate, pigs >40 kg should be allocated a minimum feeder space allowance of 42·5 mm per pig. There was little indication of a need to specify differential feeder space allowances according to group size.


Endocrinology ◽  
1999 ◽  
Vol 140 (1) ◽  
pp. 244-250 ◽  
Author(s):  
Karim Meeran ◽  
Donal O’Shea ◽  
C. Mark B. Edwards ◽  
Mandy D. Turton ◽  
Melanie M. Heath ◽  
...  

Abstract Central nervous system glucagon-like peptide-1-(7–36) amide (GLP-1) administration has been reported to acutely reduce food intake in the rat. We here report that repeated intracerebroventricular (icv) injection of GLP-1 or the GLP-1 receptor antagonist, exendin-(9–39), affects food intake and body weight. Daily icv injection of 3 nmol GLP-1 to schedule-fed rats for 6 days caused a reduction in food intake and a decrease in body weight of 16 ± 5 g (P &lt; 0.02 compared with saline-injected controls). Daily icv administration of 30 nmol exendin-(9–39) to schedule-fed rats for 3 days caused an increase in food intake and increased body weight by 7 ± 2 g (P &lt; 0.02 compared with saline-injected controls). Twice daily icv injections of 30 nmol exendin-(9–39) with 2.4 nmol neuropeptide Y to ad libitum-fed rats for 8 days increased food intake and increased body weight by 28 ± 4 g compared with 14 ± 3 g in neuropeptide Y-injected controls (P &lt; 0.02). There was no evidence of tachyphylaxis in response to icv GLP-1 or exendin-(9–39). GLP-1 may thus be involved in the regulation of body weight in the rat.


1994 ◽  
Vol 122 (3) ◽  
pp. 465-470 ◽  
Author(s):  
A. T. S. Morrow ◽  
N. Walker

SUMMARYTwo experiments of randomized block design were carried out at the Agricultural Research Institute of Northern Ireland in 1991/92 involving groups of 20 pigs fed ad libitum from single-space feeders with built-in water supply from 37 kg to slaughter at 91 kg liveweight.Treatments were replicated 16 and 6 times respectively in Experiments 1 and 2. In the first experiment, one feeder perpen was compared with two feeders per pen positioned side by side. Two feeders increased feed intake (P < 0·05) but had no significant effects on growth rate or feed conversion. With two feeders, the total time that feeders were occupied and the number of visits to feeders were both increased, while the number of enforced withdrawals from feeders and the amount of queuing were both decreased compared with the single feeder. In the second experiment, placing two feeders 2 m or more apart instead of side by side had no significant effects on feed intake or growth rate but improved feed conversion efficiency by 4%. This improvement was associated with fewer and longer visits to feeders but no difference in enforced withdrawals or queuing. In both experiments all treatments showed broadly similar patterns of diurnal feeding behaviour with two peaks of activity daily, a smaller peak pre-midday and a larger one in the afternoon. This pattern was influenced more by number of visits to feeders than by the mean duration of each visit. It is recommended that two single-space feeders are used in pens of 20 finishing pigs when non-pelleted diets are offered ad libitum and that feeders are sited some distance apart, not side by side.


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