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Effects of high-fat diets with different carbohydrate-to-protein ratios on energy homeostasis in rats with impaired brain melanocortin receptor activity.
. 2005 Jul; 289(1):R156-63.

Abstract

Changes in dietary macronutrient composition and/or central nervous system neuronal activity can underlie obesity and disturbed fuel homeostasis. We examined whether switching rats from a diet with high carbohydrate content (HC; i.e., regular chow) to diets with either high fat (HF) or high fat/high protein content at the expense of carbohydrates (LC-HF-HP) causes differential effects on body weight and glucose homeostasis that depend on the integrity of brain melanocortin (MC) signaling. In vehicle-treated rats, switching from HC to either HF or LC-HF-HP feeding caused similar reductions in food intake without alterations in body weight. A reduced caloric intake (-16% in HF and LC-HF-HP groups) required to maintain or increase body weight underlay these effects. Chronic third cerebroventricular infusion of the MC receptor antagonist SHU9119 (0.5 nmol/day) produced obesity and hyperphagia with an increased food efficiency again observed during HF (+19%) and LC-HF-HP (+33%) feeding. In this case, however, HF feeding exaggerated SHU9119-induced hyperphagia and weight gain relative to HC and LC-HF-HP feeding. Relative to vehicle-treated controls, SHU9119 treatment increased plasma insulin (2.8-4 fold), leptin (7.7-15 fold), and adiponectin levels (2.4-3.7 fold), but diet effects were only observed on plasma adiponectin (HC and LC-HF-HP<HF). Finally, SHU9119-treated LC-HF-HP-fed rats were less glucose tolerant than others. Relatively low plasma adiponectin levels likely contributed to this effect. Thus HF feeding amplifies obesity induced by impaired MC signaling, provided that the carbohydrate-to-protein (C/P) ratio is high enough. Reduction of the C/P ratio within a HF diet ameliorates hyperphagia and obesity in rats with impaired MC signaling but aggravates associated disturbances in fuel homeostasis.

Authors+Show Affiliations

Department of Animal Physiology, Unit Neuroendocrinology, University of Groningen, PO Box 14, 9750 AA Haren, The Netherlands.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

15774764

Citation

Morens, C, et al. "Effects of High-fat Diets With Different Carbohydrate-to-protein Ratios On Energy Homeostasis in Rats With Impaired Brain Melanocortin Receptor Activity." American Journal of Physiology. Regulatory, Integrative and Comparative Physiology, vol. 289, no. 1, 2005, pp. R156-63.
Morens C, Keijzer M, de Vries K, et al. Effects of high-fat diets with different carbohydrate-to-protein ratios on energy homeostasis in rats with impaired brain melanocortin receptor activity. Am J Physiol Regul Integr Comp Physiol. 2005;289(1):R156-63.
Morens, C., Keijzer, M., de Vries, K., Scheurink, A., & van Dijk, G. (2005). Effects of high-fat diets with different carbohydrate-to-protein ratios on energy homeostasis in rats with impaired brain melanocortin receptor activity. American Journal of Physiology. Regulatory, Integrative and Comparative Physiology, 289(1), R156-63.
Morens C, et al. Effects of High-fat Diets With Different Carbohydrate-to-protein Ratios On Energy Homeostasis in Rats With Impaired Brain Melanocortin Receptor Activity. Am J Physiol Regul Integr Comp Physiol. 2005;289(1):R156-63. PubMed PMID: 15774764.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Effects of high-fat diets with different carbohydrate-to-protein ratios on energy homeostasis in rats with impaired brain melanocortin receptor activity. AU - Morens,C, AU - Keijzer,M, AU - de Vries,K, AU - Scheurink,A, AU - van Dijk,G, Y1 - 2005/03/17/ PY - 2005/3/19/pubmed PY - 2005/7/14/medline PY - 2005/3/19/entrez SP - R156 EP - 63 JF - American journal of physiology. Regulatory, integrative and comparative physiology JO - Am. J. Physiol. Regul. Integr. Comp. Physiol. VL - 289 IS - 1 N2 - Changes in dietary macronutrient composition and/or central nervous system neuronal activity can underlie obesity and disturbed fuel homeostasis. We examined whether switching rats from a diet with high carbohydrate content (HC; i.e., regular chow) to diets with either high fat (HF) or high fat/high protein content at the expense of carbohydrates (LC-HF-HP) causes differential effects on body weight and glucose homeostasis that depend on the integrity of brain melanocortin (MC) signaling. In vehicle-treated rats, switching from HC to either HF or LC-HF-HP feeding caused similar reductions in food intake without alterations in body weight. A reduced caloric intake (-16% in HF and LC-HF-HP groups) required to maintain or increase body weight underlay these effects. Chronic third cerebroventricular infusion of the MC receptor antagonist SHU9119 (0.5 nmol/day) produced obesity and hyperphagia with an increased food efficiency again observed during HF (+19%) and LC-HF-HP (+33%) feeding. In this case, however, HF feeding exaggerated SHU9119-induced hyperphagia and weight gain relative to HC and LC-HF-HP feeding. Relative to vehicle-treated controls, SHU9119 treatment increased plasma insulin (2.8-4 fold), leptin (7.7-15 fold), and adiponectin levels (2.4-3.7 fold), but diet effects were only observed on plasma adiponectin (HC and LC-HF-HP<HF). Finally, SHU9119-treated LC-HF-HP-fed rats were less glucose tolerant than others. Relatively low plasma adiponectin levels likely contributed to this effect. Thus HF feeding amplifies obesity induced by impaired MC signaling, provided that the carbohydrate-to-protein (C/P) ratio is high enough. Reduction of the C/P ratio within a HF diet ameliorates hyperphagia and obesity in rats with impaired MC signaling but aggravates associated disturbances in fuel homeostasis. SN - 0363-6119 UR - https://www.unboundmedicine.com/medline/citation/15774764/Effects_of_high_fat_diets_with_different_carbohydrate_to_protein_ratios_on_energy_homeostasis_in_rats_with_impaired_brain_melanocortin_receptor_activity_ L2 - https://journals.physiology.org/doi/10.1152/ajpregu.00774.2004?url_ver=Z39.88-2003&amp;rfr_id=ori:rid:crossref.org&amp;rfr_dat=cr_pub=pubmed DB - PRIME DP - Unbound Medicine ER -