Quantitative analysis of food waste, especially food loss, has received worldwide attention in the viewpoint of efficient food supply and consumption. Food waste generation characteristics expressed as the place and the quantity are influenced by food consumption styles. Food consumption styles can be classified into Meals at home, Convenience meals, and Meals outside the home. And also food waste was classified into food loss and inedible portion, here, the two have different meaning in terms of reason for generation and the social meaning. Using Material Flow Analysis (MFA), food and food loss flow of Japan in 2008 was drawn, and food waste generation rate by food consumption styles were calculated. First result is that meat, sea foods, and fat are much consumed in externalized meal (convenience meals or meals outside the home). After allocating foodstuffs to each food consumption style, we made a flow diagram of food waste. In wholistic viewpoint, it indicated that food loss are generated mostly in households and restaurants, which is caused by consumer's carelessness. In the viewpoint of food consumption style, convenience meals has the lowest level on total food loss including consumer sector and industrial sector. However, in only industrial part, convenience meals has the highest level on food loss, which means convenience meals increase food loss in supply chain before reaching consumer. Social changes have driven the increase of convenience meals, but also food waste weight-charged system, which is new policy in Korea, may cause the increase of pre-cooked food consumption in households and restaurants. Therefore, it is necessary to do monitor the change of food consumption styles and whole sectors of food waste generation sectors. Material Flow Analysis can be considered as a useful tool to monitor the change and assess the performance by the system from a holistic perspective.