CHAPTER 1 Introduction 1 Section 1. Background 3 Section 2. Content and method 8 CHAPTER 2 Previous Studies 11 Section 1. Empirical application of a behavioral change model 13 CHAPTER 3 Analysis of the Current State of Lifestyle Diseases 31 Section 1.Concept and classification of lifestyle diseases 33 Section 2. Current prevalence of lifestyle diseases and associated complications 51 CHAPTER 4 Analysis of the Cause of the Cognition-Practice Gap 67 Section 1. Analysis method 69 Section 2. Analysis results 74 Section 3. Sintering 91 CHAPTER 5 Conclusion and Policy Implications 95 Reference 105