Monosodium glutamate (MSG) is one of the most widely employed food taste enhancers and there is a safety concern on glutamate with respect to the obesity epidemics. The reported effects are attributed to the actions of MSG in the brain, which would affect food intake, body weight and lipid metabolism. The aim of this study was to evaluate the effects of the addition of MSG to the rat chow on body weight, food intake, plasma glucose and aminotransferases and plasma and liver lipids in adult obese and diabetic IIMb/Beta rats. Twelve male, 70-days-old rats randomly divided in two groups -Control and MSG (with 1 mg MSG/g of feed)- were housed in individual cages and allowed food and water ad libitum during 40 days. At day forty glycemia, total cholesterol and fractions, triacylglycerols (TAG), aspartate amino transferase (AST), alanine amino transferase (ALT) were quantified. Animals were euthanized, and abdominal fat pads and livers were excised and weighed. Liver lipids were extracted and quantified. There were no significant differences in feed intake, final body weight, perigonadal fat depots, plasmatic glucose and lipids, AST and ALT between groups. Retroperitoneal fat depots and liver relative weights as well as liver total lipid content were significantly higher in the MSG group. A relevant effect of MSG intake on abdominal fat and liver weight as well as liver lipid content was demonstrated in this study.