Potency of naloxone's anorectic effect in rats is dependent on diet preference

Modulation of feeding behavior by neuropeptide Y (NPY) and opioids is well established, but the possibility that these neural influences provoke specific appetites, NPY for carbohydrate and opioids for fat, has also been considered. In other studies, intake of standard chow after NPY stimulation can be blocked by naloxone, indicating an interaction between these systems in the regulation of feeding. The present experiments examined the nature of NPY-opioid interactions in diet selection. Rats were administered NPY and naloxone concurrently, then chose between high-fat and high-carbohydrate diets. Subcutaneous administration of naloxone (0.01-0.3 mg/kg) potently reduced intake of the preferred diet, but not the nonpreferred diet. A similar pattern of selection was seen in a separate experiment where the same doses of naloxone were administered after 24-h food deprivation. These data support the idea that the opioid system mediates the “rewarding” aspects of feeding.

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Role of carbohydrate type on diet selection in neuropeptide Y-stimulated rats

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1997.273.6.r2040 ◽

1997 ◽

Vol 273 (6) ◽

pp. R2040-R2045 ◽

Cited By ~ 4

Author(s):

Michael J. Glass ◽

James P. Cleary ◽

Charles J. Billington ◽

Allen S. Levine

Keyword(s):

Neuropeptide Y ◽

High Fat Diet ◽

Corn Starch ◽

High Carbohydrate Diet ◽

High Fat ◽

Carbohydrate Diet ◽

Carbohydrate Source ◽

High Carbohydrate ◽

Diet Versus ◽

High Sucrose

We tested whether carbohydrate source (corn starch, sucrose, Polycose) influences the choice between a high-fat and high-carbohydrate diet in spontaneously feeding rats and in rats stimulated to eat by neuropeptide Y (NPY) administration or food deprivation. Rats were tested under three diet options: 1) a high-fat diet versus a high-corn starch diet; 2) a high-fat diet versus a high-sucrose diet; and 3) a high-fat diet versus a high-Polycose diet. During daily and stimulated feeding rats ate more of the high-carbohydrate diet than the fat diet when the source of carbohydrate was sucrose or Polycose; however, when corn starch was provided as the carbohydrate source rats ate more of the high-fat diet. Food-deprived rats increased intake of both the high-fat and the high-carbohydrate diets, with the proportion of energy ingested from each of the diets resembling that noted during 3 days of spontaneous feeding. NPY-injected rats ate more of both the high-fat and high-carbohydrate diets during diet options 1 and 3, but not during option 2 when the high-sucrose and high-fat diets were offered concurrently. In that case, rats did not significantly increase their intake of the high-fat diet. Although carbohydrate source and NPY administration each influenced diet selection, altering the source of carbohydrate had a more marked effect.

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High-fat diet preference and overeating mediated by postingestive factors in rats

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1998.275.5.r1511 ◽

1998 ◽

Vol 275 (5) ◽

pp. R1511-R1522 ◽

Cited By ~ 15

Author(s):

François Lucas ◽

Karen Ackroff ◽

Anthony Sclafani

Keyword(s):

High Fat Diet ◽

Liquid Diet ◽

Flavor Preference ◽

High Fat ◽

High Carbohydrate ◽

Flavored Solution ◽

Diet Preference ◽

Choice Tests ◽

Selection Of

The role of postingestive factors in the preference for and overconsumption of high-fat (HF) foods, relative to high-carbohydrate (HC) foods, was investigated using a self-regulated intragastric feeding procedure. On one-bottle training days, rats drank one flavored saccharin solution [conditioned stimulus (CS) + HF] paired with intragastric infusions of an HF liquid diet, a second flavored solution (CS+HC) paired with an HC liquid diet, and a third flavored solution (CS−) paired with intragastric water. The diets had the same energy and protein content; the CS solutions and infusions along with chow were available ad libitum. The rats drank more CS and self-infused more diet on HF than HC training days. In two-bottle choice tests, the rats preferred the CS+HF to the CS+HC and both CS+HF and CS+HC to the CS−. The rats consumed more CS+HF than CS+HC by taking more bouts per day; bout sizes did not reliably differ. In a subsequent experiment, rats preferred the CS+HF even though diet intakes in training were matched. In a final experiment, the CS+HC and CS+HF intakes were equated in training by diluting the HC diet. Now the rats did not reliably prefer the CS+HF to the CS+HC, yet caloric intakes were much higher on CS+HF than CS+HC training days. Thus, relative to an isocaloric HC diet, the postingestive effects of HF diets stimulate overeating and condition a stronger flavor preference. Reduced satiety rather than increased reinforcement may be the direct promoter of overeating. However, postingestive reinforcement may enhance the selection of HF foods when a choice of HF and HC foods is available.

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723-P: Effect of Low-Carbohydrate High-Fat vs. High-Carbohydrate Low-Fat Diet on HbA1c Control in Chinese Patients with Type 2 Diabetes

Diabetes ◽

10.2337/db20-723-p ◽

2020 ◽

Vol 69 (Supplement 1) ◽

pp. 723-P

Author(s):

LINGWANG AN ◽

DANDAN WANG ◽

XIAORONG SHI ◽

CHENHUI LIU ◽

KUEICHUN YEH ◽

...

Keyword(s):

Type 2 Diabetes ◽

Chinese Patients ◽

High Fat ◽

Low Fat ◽

High Carbohydrate ◽

Low Fat Diet ◽

Low Carbohydrate ◽

Hba1c Control

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Response of Rat Exocrine Pancreas to High-Fat and High-Carbohydrate Diets

Proceedings of The Society for Experimental Biology and Medicine ◽

10.1046/j.1525-1373.2000.22344.x ◽

2000 ◽

Vol 223 (3) ◽

pp. 310-315 ◽

Cited By ~ 29

Author(s):

Parimal Chowdhury ◽

Masahiro Nishikawa ◽

George W. Blevins ◽

Phillip L. Rayford

Keyword(s):

Exocrine Pancreas ◽

High Fat ◽

High Carbohydrate ◽

Rat Exocrine Pancreas

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The effects of a high-fat/high-carbohydrate meal on leukocyte populations in adults with chronic spinal cord injury

Spinal Cord Series and Cases ◽

10.1038/s41394-021-00412-7 ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Gabriel U. Dix ◽

Garett S. Jackson ◽

Kendra R. Todd ◽

Jan W. van der Scheer ◽

Jeremy J. Walsh ◽

...

Keyword(s):

Spinal Cord ◽

Spinal Cord Injury ◽

High Fat ◽

Chronic Spinal Cord Injury ◽

High Carbohydrate ◽

Cord Injury ◽

Leukocyte Populations ◽

Carbohydrate Meal

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Effects of Palm Stearin versus Butter in the Context of Low-Carbohydrate/High-Fat and High-Carbohydrate/Low-Fat Diets on Circulating Lipids in a Controlled Feeding Study in Healthy Humans

Nutrients ◽

10.3390/nu13061944 ◽

2021 ◽

Vol 13 (6) ◽

pp. 1944

Author(s):

Parker N. Hyde ◽

Teryn N. Sapper ◽

Richard A. LaFountain ◽

Madison L. Kackley ◽

Alex Buga ◽

...

Keyword(s):

Particle Distribution ◽

Oxidized Ldl ◽

Saturated Fatty Acids ◽

Density Lipoprotein ◽

Palm Stearin ◽

High Fat ◽

Low Fat ◽

High Carbohydrate ◽

Ldl Particles ◽

Low Carbohydrate

Background. Foods rich in saturated fatty acids (SFAs) have been discouraged by virtue of their cholesterol-raising potential, but this effect is modulated by the food source and background level of carbohydrate. Objective. We aimed to compare the consumption of palm stearin (PS) versus butter on circulating cholesterol responses in the setting of both a low-carbohydrate/high-fat (LC/HF) and high-carbohydrate/low-fat (HC/LF) diet in healthy subjects. We also explored effects on plasma lipoprotein particle distribution and fatty acid composition. Methods. We performed a randomized, controlled-feeding, cross-over study that compared a PS- versus a Butter-based diet in a group of normocholesterolemic, non-obese adults. A controlled canola oil-based ‘Run-In’ diet preceded the experimental PS and Butter diets. All diets were eucaloric, provided for 3-weeks, and had the same macronutrient distribution but varied in primary fat source (40% of the total fat). The same Run-In and cross-over experiments were done in two separate groups who self-selected to either a LC/HF (n = 12) or a HC/LF (n = 12) diet track. The primary outcomes were low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein (HDL)-C, triglycerides, and LDL particle distribution. Results. Compared to PS, Butter resulted in higher LDL-C in both the LC/HF (13.4%, p = 0.003) and HC/LF (10.8%, p = 0.002) groups, which was primarily attributed to large LDL I and LDL IIa particles. There were no differences between PS and Butter in HDL-C, triglycerides, or small LDL particles. Oxidized LDL was lower after PS than Butter in LC/HF (p = 0.011), but not the HC/LF group. Conclusions. These results demonstrate that Butter raises LDL-C relative to PS in healthy normocholesterolemic adults regardless of background variations in carbohydrate and fat, an effect primarily attributed to larger cholesterol-rich LDL particles.

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