title: Meal pattern of male rats maintained on amino acid supplemented diets: the effect of tryptophan, lysine, arginine, proline and threonine.
abstract: The macronutrient composition of the diet has been shown to affect food intake, with proteins having distinct effects. The present study investigated the effect of diet supplementation with individual amino acids (tryptophan, lysine, arginine, proline and threonine) on meal pattern among male rats. Meal pattern and body weight were monitored for two weeks. Proline and threonine had minimal effects on meal pattern, while the most pronounced changes were observed in the tryptophan group. Both tryptophan and lysine decreased overall food intake, which was translated into a reduction in body weight. The reduced food intake of the tryptophan group was associated with an increase in meal size, intermeal intervals (IMI) and meal time and a decrease in meal number. The decrease in the food intake of the lysine group was associated with a reduction in both IMI and meal number, and this was accompanied by an increase in meal time. Arginine increased meal number, while decreasing IMI. Proline and threonine had a minimal effect on meal pattern. Lysine seems to increase satiety, and arginine seems to decrease it, while tryptophan seems to increase satiety and decrease satiation. Accordingly, changes in meal patterns are associated with the type of amino acid added to the diet.
authors.affiliation: Department of Nutrition and Food Sciences, Faculty of Agricultural and Food Sciences, American University of Beirut, P.O. Box 11-0236, Beirut 1107 2020, Lebanon. raghadayaso@hotmail.com.
authors.forename: Raghad
authors.initials: R
authors.lastname: Ayaso
authors.affiliation: Department of Nutrition and Food Sciences, Faculty of Agricultural and Food Sciences, American University of Beirut, P.O. Box 11-0236, Beirut 1107 2020, Lebanon. hg15@aub.edu.lb.
authors.forename: Hala
authors.initials: H
authors.lastname: Ghattas
authors.affiliation: Department of Nutrition and Food Sciences, Faculty of Agricultural and Food Sciences, American University of Beirut, P.O. Box 11-0236, Beirut 1107 2020, Lebanon. ma192@aub.edu.lb.
authors.forename: Mohamad
authors.initials: M
authors.lastname: Abiad
authors.affiliation: Department of Nutrition and Food Sciences, Faculty of Agricultural and Food Sciences, American University of Beirut, P.O. Box 11-0236, Beirut 1107 2020, Lebanon. omar.obeid@aub.edu.lb.
authors.forename: Omar
authors.initials: O
authors.lastname: Obeid
mesh_terms: D000596:Amino Acids / Q000008:administration & dosage*; D000818:Animals; D001120:Arginine / Q000008:administration & dosage; D001835:Body Weight / Q000187:drug effects; D019587:Dietary Supplements; D002149:Energy Intake; D005247:Feeding Behavior; D008239:Lysine / Q000008:administration & dosage; D008297:Male; D011392:Proline / Q000008:administration & dosage; D051381:Rats; D017207:Rats, Sprague-Dawley; D013912:Threonine / Q000008:administration & dosage; D014364:Tryptophan / Q000008:administration & dosage
chemical_list: D000596:Amino Acids; D013912:Threonine; D014364:Tryptophan; D001120:Arginine; D011392:Proline; D008239:Lysine