In the paper the short- and long-term glycaemic response after 4 diet programmes was evaluated. Each diet programme was alternatively administered to 6 healthy cats for 30 days. At the end of each period cats were weighed and underwent blood sampling for glucose and fructosamine determination. Glycaemia was measured every 2 hours for 24 hours using an automated glucometer. Very high protein level and low starch (VHP÷LS) and high protein and moderate starch level (HP÷LS) diets showed glucose (Mean and Peak) and fructosamine values signi cantly lower compared to the moderate protein and high starch diets (MP/HS). It is likely that these results are due to the contemporary e ect of the following nutritional characteristics: protein level, protein/starch ratio and dietary bre. All these parameters were higher in VHP/LS and HP/MS diets. These preliminary results suggest that the use of diets with high protein/starch ratio and soluble bre levels favours the carbohydrate metabolism of healthy cats.