Abstract Background Insulin response to a meal is crucial for metabolic health in cats, influencing the risk of metabolic disorders. Hypothesis/Objectives Investigate dietary macronutrient compositions on fasted and post-prandial insulin and glucose responses, and lipid profiles, in lean and obese cats. Animals Nine lean and 9 obese, male neutered colony cats. Methods Cats were fed 3 extruded dry diets: low protein (LP: 28% protein, 40% fat, and 32% nitrogen-free extract NFE), low fat (LF: 40% protein, 30% fat, and 30% NFE), and low carbohydrate (LC: 36% protein, 41% fat, and 23% NFE) for 28 days using a 3 × 3 Latin square design. Fasted and post-prandial blood samples were collected to measure serum insulin and whole blood glucose concentrations, and fasted samples were analyzed for serum cholesterol, triacylglycerol (TAG), nonesterified fatty acid (NEFA), very low-density lipoprotein (VLDL), low-density lipoprotein cholesterol (LDL-c), and high-density lipoprotein cholesterol (HDL-c) concentrations at the end of each period. Results No differences were found in serum insulin, glucose, cholesterol, NEFA, TAG, HDL-c, LDL-c, or VLDL concentrations between lean and obese cats (P .05) suggesting dyslipidemia was not present in the obese cats. The LP diet resulted in lower post-prandial insulin concentrations compared with the LC and LF diets (P = .01) which was attributed to lower protein intake with the LP diet. As expected, the LF diet led to lower fasted serum cholesterol and LDL-c concentrations compared with the LP and LC diets (P .001). Conclusions and clinical importance These findings document the metabolic flexibility of cats and suggest that dietary macronutrient composition, particularly protein content, plays an important role in modulating insulin responses in adult, otherwise healthy, cats.
Godfrey et al. (Thu,) studied this question.