Adaptation of lipid-induced satiation is not dependent on caloric density in rats

• Published in: Physiology & behavior 2008-03, Vol.93 (4), p.930-936
• Main Authors: Paulino, G, Darcel, N, Tome, D, Raybould, H
• Format: Article
• Language: English
• Subjects: Adaptation, Physiological - physiology; Analysis of Variance; Animals; Behavior, Animal - physiology; Behavioral psychophysiology; Biological and medical sciences; Body Composition - drug effects; Diet adaptation; Eating - drug effects; Feeding Behavior - physiology; Food intake; Food Preferences - drug effects; Fundamental and applied biological sciences. Psychology; High fat; Lipids - pharmacology; Male; Meal pattern analysis; Proto-Oncogene Proteins c-fos - metabolism; Psychiatry; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Rats; Rats, Sprague-Dawley; Satiation; Satiation - drug effects; Satiation - physiology; Time Factors
• ISSN: 0031-9384; 1873-507X
• DOI: 10.1016/j.physbeh.2007.12.015

Abstract Food intake is modulated by ingestive (gastrointestinal) and post-ingestive signals; ingested fat is potent to produce short-term satiety (satiation) but this can be modified by long-term ingestion of a high fat diet. Aim Determine whether altered lipid-induced satiation is dependent on the fat content of the diet, rather than increased caloric density or changes in adiposity. Methods Initial experiments determined the differences in the microstructure of meal patterns in rats fed a high fat diet (HF: 38% fat kcal) and in rats pair-fed an isocaloric, isonitrogenous low fat diet (LF: 10% fat kcal) and changes in meal patterns measured after long-term maintenance on the HF diet. Results Rats fed the HF diet had a significant 50% increase in meal frequency compared to rats fed the LF diet; in addition, there was a significant reduction in meal size (32%) and inter meal interval (38%) consistent with induction of satiation. After 8 weeks on the HF diet, these parameters tend to approach those of rats maintained on the LF diet. There was a significant 56% decrease in the activation of neurons in the NTS in response to intragastric gavage of lipid in rats maintained for 8 weeks on the HF compared to LF diet. Conclusion Dietary fat alters meal patterns consistent with induction of a short-term satiety signal. This signal is attenuated with long-term exposure to dietary lipid, in the absence of ingestion of additional calories or changes in body weight. This adaptation of short-term satiety might contribute to diet-induced obesity.