The purposes of this study were to determine whether perceived food insecurity significantly influences food purchasing behaviors, food preparation practices, and life satisfaction; and to verify the moderating effect of generation in South Korea. Structural equation modeling and multi-group analyses were conducted to confirm the research model and test the hypotheses. Perceived food insecurity positively influenced food purchasing behaviors and food preparation practices. In addition, this study verified the presence of a significant negative relationship between perceived food insecurity and life satisfaction. Notably, a greater awareness of food insecurity in Generation M increased food preparation practices, and the negative impact of perceived food insecurity on life satisfaction was more strongly exhibited in the older generation than in the younger generation. This presents a need to pay greater attention to food insecurity issues at the government level and accelerate related future research. Specifically, it will be necessary to establish a structured educational environment and support services for systematic food security education. Also, rather than educating people with high levels of perceived food insecurity about why they should eat healthy food, proactive efforts should first be made to remove barriers to healthy eating habits. As a preventive measure against the worsening of food insecurity, more solutions should be prepared from a macroscopic perspective in addition to implications from the microscopic perspective mentioned so far.