Influence of dietary protein and lipid on weight loss in obese ovariohysterectomized cats

Objective-To determine effects of dietary lipid and protein on development of hepatic lipidosis (HL) and on physical and biochemical indices following rapid weight loss in cats. Animals-24 ovariohysterectomized cats. Procedure-Cats were fed a high energy diet until they gained 30% of their i deal body weight and then randomly assigned to receive 1 of 4 weight-reduct ion diets (6 cats/diet) at 25% of maintenance energy requirements per day. Diets contained a low or high quality protein source and a lipid source def icient or sufficient in long chain essential fatty acids (LCEFA). Serum and plasma samples and liver biopsy specimens were obtained for biochemical an alyses and determination of hepatic lipid content before and after weight g ain and during and after weight loss. Results-Irrespective of weight-reduction diet fed, all cats lost weight at a comparable rate (4.51 to 5.00 g/d/kg of obese body weight). Three cats de veloped hepatic lipidosis. Significant changes in plasma insulin, cholester ol, triglyceride, and serum glucose concentrations were detected after weig ht gain and weight loss in all diet groups, but values for these variables did not differ among groups. Conclusions and Clinical Relevance-Cats can lose 25 to 30% of their obese b ody weight over 7 to 9 weeks without developing overt clinical signs of HL, provided that weight-reduction diets are highly palatable, contain a high quality protein, have a source of LCEFA, and are fortified with vitamins an d microminerals. However, rapid weight loss may increase risk factors assoc iated with development of diabetes mellitus.