Influence of high-protein and high-carbohydrate diets on serum lipid and fructosamine concentrations in healthy cats

Abstract

Diabetic cats can benefit from a high-protein and low-carbohydrate diet in terms of higher diabetic remission rates, lower fructosamine concentrations and improved glycaemic control. Hypercholesterolaemia in cats with diabetes mellitus has been associated with lower remission rates. A recent publication demonstrated that a high-protein and low-carbohydrate diet resulted in significantly elevated serum cholesterol concentrations in lean, overweight and diabetic cats. The concept that a traditional high-protein and low-carbohydrate diet causes increased cholesterol concentrations in healthy cats is relatively new and requires further investigation.

This mini-dissertation focused on clarifying whether high-protein and high-carbohydrate diets exert differential effects on serum cholesterol, triglyceride, and fructosamine concentrations in healthy cats.

This mini-dissertation describes the results of a randomised, crossover diet trial that was performed in thirty-five healthy shelter cats. Prior to enrolment, cats were fed a commercial baseline diet. Following baseline health assessments, cats were randomised into groups receiving either the high-protein or high-carbohydrate diet for four weeks. The cats were then fed a washout diet for four weeks before being transitioned to whichever diet they had not yet been subjected to. Fasting serum cholesterol, triglyceride and fructosamine concentrations were determined at the end of each four-week diet period. Weekly body condition score (BCS), body weight measurements and environmental temperatures were evaluated throughout the study.

Cats on the high-protein diet had significantly higher serum cholesterol and triglyceride, yet significantly lower serum fructosamine concentrations than cats on the baseline diet (P<0.001). Among the cats on the high-protein diet, the observed increases in cholesterol and triglycerides were significantly more pronounced in cats with BCS < 5. In contrast, cats on the high-carbohydrate diet had significantly lower serum cholesterol concentrations (P<0.001) relative to cats on the baseline diet.

The empirical evidence base currently suggests that diets with high protein but low carbohydrate contents may be beneficial for short-term glucose control in healthy cats. The reduction in cholesterol and triglyceride concentrations among overweight cats on a high-protein diet, relative to lean cats on the same diet, suggests that overweight cats process cholesterol and triglycerides differently from lean cats. These findings from healthy cats, that a high-protein diet significantly increased cholesterol and triglyceride concentrations while a high-carbohydrate diet significantly decreased cholesterol concentrations relative to baseline diets, warrants further investigation.