title: Fasting plasma triglyceride levels and fat oxidation predict dietary obesity in rats.
abstract: We investigated whether fuel metabolism prior to high-fat feeding differs in outbred Sprague-Dawley rats either prone or resistant to diet-induced obesity. Chow-fed rats were deprived of food, and blood was collected 12, 18, and 24 h later. Rats were then fed a high-fat diet ad libitum for up to 4 weeks to assess weight gain. Blood samples were analyzed for a variety of metabolic fuels and hormones. Only fasting plasma triglyceride concentrations showed a positive correlation with the weight gain during the high-fat feeding period, with concentrations after 18 h of fasting showing the most consistent relationship to weight gain. Body weights and fat pad weights did not correlate with fasting plasma triglyceride concentrations before high-fat feeding. The amount of 14CO(2) recovered from gavaged [14C]palmitic acid in chow-fed rats negatively correlated with weight gain during the subsequent period of high-fat feeding. These results show that there are preexisting differences in fat catabolism that may underlie differential susceptibility to diet-induced obesity; in particular, fasting levels of plasma triglycerides and fatty acid oxidation may be early predictive markers for this susceptibility.
authors.affiliation: Monell Chemical Senses Center, 3500 Market Street, Philadelphia, PA 19104, USA. hongji@monell.org
authors.forename: Hong
authors.initials: H
authors.lastname: Ji
authors.forename: Mark I
authors.initials: MI
authors.lastname: Friedman
mesh_terms: D000273:Adipose Tissue / Q000502:physiology; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D001823:Body Composition / Q000187:drug effects; D002245:Carbon Dioxide / Q000378:metabolism; D004032:Diet; D004041:Dietary Fats / Q000378:metabolism*; D004734:Energy Metabolism / Q000502:physiology; D005215:Fasting / Q000097:blood / Q000378:metabolism*; D008297:Male; D009765:Obesity / Q000097:blood / Q000378:metabolism*; D009929:Organ Size / Q000502:physiology; D010084:Oxidation-Reduction; D019308:Palmitic Acid / Q000493:pharmacokinetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D014280:Triglycerides / Q000097:blood*; D015430:Weight Gain / Q000502:physiology
chemical_list: D001786:Blood Glucose; D004041:Dietary Fats; D014280:Triglycerides; D002245:Carbon Dioxide; D019308:Palmitic Acid