Impact of commercially available diabetic prescription diets on short-term postprandial serum glucose, insulin, triglyceride and free fatty acid concentrations of obese cats.

Diet therapy is an important treatment component available for obese cats. In this study, the impact of four commercially available prescription diet regimens (1 for general use and 3 aimed at treating obesity and diabetes mellitus (DM)) on short-term postprandial serum glucose, insulin, triglyceride and nonesterified fatty acid (NEFA) concentrations was investigated with five obese cats. The diet regimens used were as follows: C/D dry (general use: moderate protein, moderate fat, high carbohydrate and low fiber), M/D dry (DM: high protein, high fat, low carbohydrate and high fiber), W/D dry (DM: high protein, low fat, high carbohydrate and high fiber) and Diabetic dry (DM: high protein, low fat, low carbohydrate and high fiber). A significant reduction (10-13%) in postprandial glucose (area under the curve; AUC) was observed with the M/D and Diabetic diets, which both contained lower concentrations of carbohydrates than the C/D diet. An accompanying significant reduction (30-36%) in postprandial insulin AUC was also observed with the three DM diets, which all had higher amounts of fiber, as compared with the C/D diet. Lastly, a significant increase (32-65%) in postprandial NEFA AUC was observed with the M/D and Diabetic diets as compared with the C/D diet. Therefore, dietary amounts of carbohydrates and fiber, as opposed to protein content or dietary fat, appear to have a very significant impact on postprandial glycemia and subsequent insulin requirement levels in obese cats. In addition, dietary amounts of carbohydrates may also impact lipid metabolism in obese cats.