The aim of this study is to propose a triple bottom line (TBL) framework to determine the key metrics of environmental, social, and economic sustainability and predict the impacts of these metrics on sustainability in circular economy. First, TBL working framework has been established to determine the key environmental, social, and economic sustainability metrics. Then, the system dynamics (SD) model is developed to estimate the effects of TBL metrics within a smart closed-loop food chain. The proposed SD model reinforces the idea that each metric supports more than one dimension of sustainability in that food loss can have implications for sustainability dimensions. With the help of the incorporated metrics, management can see the supply chain and examine various parts of it, such as production, distribution, the impact of buying decisions, etc. The results showed which stages of the food supply chain need attention because of the high value-added product losses and if the company targets are enough to reduce greenhouse gas emissions even though the production volume will increase in the coming years. This article contributes to the literature by determining the key metrics of TBL sustainability in the smart closed-loop supply chain in the food industry.