An increasingly aging society and higher prevalence rates of lifestyle-related diseases are significant problems in advanced countries. There are social requirements of integrated services for medical care, welfare, and healthcare. In this paper, we propose the concept of a Life Support Network (LSN) including a Wellness Support System (WSS) which is an information system can be used to improve the health with risk of becoming lifestyle-related diseases at anywhere and at any time (ubiquitous environment). The architecture of WSS enables easy operation and flexible information environment with various terminals, applications, and interface adaptability. We also introduce an Integrated Health Improvement Supporting System (IHISS) as a practical implemented example in WSS. A developed nutritional management function as key element of IHISS is shown as an example of IHISS application.