Sustainable food consumption is an essential component of sustainable development. Previous literature mainly focused on consumers' environmentally friendly consumption, and paid less attention to their avoidance of unsafe consumption. This article investigated the effect of loneliness-an important psychological and social trend-on consumers' avoidance of unsafe food and the associated mechanisms. Based on a survey with 120 student participants and an experimental study with 315 non-student participants, we found that loneliness made consumers avoid unsafe food, but not safe food. We further verified that consumers' perceived immune status and concern for negative impression worked as two mechanisms between the relationship of loneliness and food avoidance. Moreover, we revealed a moderating mediation effect of food safety risk, where the indirect effect of loneliness on food avoidance via both perceived immune status and concern for negative impression only existed for unsafe food. This article extended the research setting of sustainable consumption from increasing positive consumptions to decreasing negative ones, and identified the influential factors from the interaction of consumer characteristics and food features.