<;P>;PROBLEM TO BE SOLVED: To provide a food, a drink and a medicine each for improving the accumulation of body fats. <;P>;SOLUTION: Provided is a body fat accumulation-improving agent or a metabolic syndrome-improving agent characterized by containing D-tagatose and/or its derivative as an active ingredient. Provided are the body fat accumulation-improving agent having an internal organ fat accumulation-improving action or an action for improving hyperlipemia and hyperglycemia; the metabolic syndrome-improving agent having an action for improving internal organ fat accumulation, hyperlipemia and hyperglycemia; and a medicine, a food, a drink and a feed each using them. <;P>;COPYRIGHT: (C)2010,JPO&INPIT