The effect of melatonin, a hormone that triggers biological rhythms, was examined in relation to food intake and macronutrient selection. Wistar rats (n = 48) of both sexes were divided into 3 groups and offered a simultaneous choice of 2 diets: a carbohydrate-rich diet and a protein-rich diet, with a different type of carbohydrate and protein in each of the groups. Increased short- (4h post-injection) and long-term (12h post-injection) nocturnal total food intake was found following intraperitoneal administration of melatonin (10 000 and 15 000 pg/ml blood) at dark onset. Melatonin increased short-term carbohydrate-rich diet intake similarly across sensory contrasting diets (dextrin/cornstarch, cornstarch, and sucrose/cornstarch) and genders. However, melatonin caused an inconsistent increase in protein-rich diet intake across the various diets (casein, soy isolate, and egg protein) and genders. In conclusion, melatonin favors carbohydrate intake at the beginning of the activity period, and may act as a time indicator that provides a night signal.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.78238 |
| Date | January 2002 |
| Creators | Angers, Kathleen |
| Contributors | Thibault, Louise (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (School of Dietetics and Human Nutrition.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001985472, proquestno: AAIMQ88146, Theses scanned by UMI/ProQuest. |
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