The Effect of Isoleucine Supplementation on Body Weight Gain and Blood Glucose Response in Lean and Obese Mice

• Published in: Nutrients 2020-08, Vol.12 (8), p.2446
• Main Authors: O'Rielly, Rebecca, Li, Hui, Lim, See Meng, Yazbeck, Roger, Kritas, Stamatiki, Ullrich, Sina S, Feinle-Bisset, Christine, Heilbronn, Leonie, Page, Amanda J
• Format: Article
• Language: English
• Subjects: amino acid; Amino acids; Animals; Blood Glucose - metabolism; Body fat; Body weight; Body weight gain; Carbohydrates; Cholesterol; chronic supplementation; Diet; Diet, High-Fat - adverse effects; Dietary Supplements; Drinking water; Emptying; Energy expenditure; Energy intake; Ethics; Gastric emptying; Glucose; Glucose Intolerance - diet therapy; Glucose Intolerance - prevention & control; Glucose tolerance; Glucose Tolerance Test; High fat diet; Humans; Hyperglycemia - prevention & control; Intolerance; Isoleucine; Isoleucine - administration & dosage; Isoleucine - pharmacology; Laboratories; Lipids; Liver; Male; Metabolism; Metabolites; Mice, Inbred C57BL; Negative Results; Nutritional Physiological Phenomena - physiology; Obesity; Obesity - metabolism; Obesity - prevention & control; oral glucose tolerance test; Plasma; Proteins; Quotients; Respiratory quotient; Rodents; Software; Thinness - metabolism; Weight control; Weight Gain - drug effects
• ISSN: 2072-6643; 2072-6643
• DOI: 10.3390/nu12082446

Chronic isoleucine supplementation prevents diet-induced weight gain in rodents. Acute-isoleucine administration improves glucose tolerance in rodents and reduces postprandial glucose levels in humans. However, the effect of chronic-isoleucine supplementation on body weight and glucose tolerance in obesity is unknown. This study aimed to investigate the impact of chronic isoleucine on body weight gain and glucose tolerance in lean and high-fat-diet (HFD) induced-obese mice. Male C57BL/6-mice, fed a standard-laboratory-diet (SLD) or HFD for 12 weeks, were randomly allocated to: (1) Control: Drinking water; (2) Acute: Drinking water with a gavage of isoleucine (300 mg/kg) prior to the oral-glucose-tolerance-test (OGTT) or gastric-emptying-breath-test (GEBT); (3) Chronic: Drinking water with 1.5% isoleucine, for a further six weeks. At 16 weeks, an OGTT and GEBT was performed and at 17 weeks metabolic monitoring. In SLD- and HFD-mice, there was no difference in body weight, fat mass, and plasma lipid profiles between isoleucine treatment groups. Acute-isoleucine did not improve glucose tolerance in SLD- or HFD-mice. Chronic-isoleucine impaired glucose tolerance in SLD-mice. There was no difference in gastric emptying between any groups. Chronic-isoleucine did not alter energy intake, energy expenditure, or respiratory quotient in SLD- or HFD-mice. In conclusion, chronic isoleucine supplementation may not be an effective treatment for obesity or glucose intolerance.