PURPOSE: To suppress rise in blood sugar value and secretion amount of insulin without reducing palatability by adding a slightly digestible dextrin containing a sufficient amount of a slightly digestible component to a carbohydrate in a pet food.

CONSTITUTION: 5-100 pts.wt. of a slightly digestible dextrin containing at least 30wt.%, preferably ≥50wt.% of a slightly digestible component is added to 100 pts.wt. of a carbohydrate in a pet food. A pet food effective for preventing and improving fatness is obtained.