A food for preventing life style-related diseases of the present invention contains a mung bean protein degradation product. The mung bean protein degradation product is obtained by hydrolyzing a mung bean-derived protein with a protease. In the mung bean protein degradation product, the dipeptide or tripeptide content in the entire peptides is preferably 10% or more. The food for preventing life style-related diseases of the present invention is preferable for preventing in particular hypertension, arteriosclerosis, and obesity, for example. The present invention also provides an anti-hypertensive agent, an anti-arteriosclerotic agent, a vascular intimal hypertrophy inhibitor, and an anti-obesity agent containing the mung bean protein degradation product. Furthermore, the present invention provides a diet food containing the mung bean protein degradation product. The mung bean protein degradation product is obtained from naturally-occurring materials that have been conventionally used as foods, and thus it has little side effects and a high safety. Furthermore, this degradation product can be produced from a by-product obtained in the process of producing bean-starch vermicelli, and thus it is environmentally friendly in view of utilizing waste materials, and is expected to contribute to the recycling-based society.