Metabolic syndrome relieving or prophylactic agent, as well as beverages containing this, food and feed

The present invention provides a metabolic syndrome relieving or preventing agent containing barley bran, or a α- amylase treated as an active ingredient. The present invention also provides a metabolic syndrome relieving or preventing agent containing a water-insoluble component of the α- amylase treated product of barley bran as an active ingredient. According to the present invention, to suppress accumulation of visceral fat, to enable improvement or prevention of metabolic syndrome, metabolic syndrome relieving or preventing agent derived from natural products is provided.