Until today, inadequate food supply, malnutrition, food adulteration, etc., are still the key concern in developing economies. In order to address these issues of food security crisis, and to stimulate a sustainable supply of liquid milk (LM), a consumer behavior model was created, in which consumers’ perceived knowledge, trust and risk were the major catalysts. To shed light on this context, the study examined the effect of consumers’ perceived knowledge (PK) on their perceived risk (PR) and trust (in information sources and in the product). Further, the influence of consumers’ perceived knowledge, risk, and trust on their attitude and purchase intention (PI) were investigated via an exclusive survey design. The survey was conducted in the urban area of Dhaka and Chittagong, Bangladesh. The sample of 712 households was selected randomly and interviewed using a structured questionnaire. The data were analyzed employing descriptive statistics, exploratory factor analysis, confirmatory factor analysis, and structural equation modelling. The results show that during a food security crisis, consumers’ perceived knowledge amplifies their perceived risk and their trust in information sources (ISs). During such a period, their perceived knowledge does not induce purchase intention but trust in ISs does. Again, consumers’ perceived risk leads to reduced trust in products, and hence in LM, but not reduced trust in ISs. Moreover, a paradoxical influence was found, where consumers’ perceived risks had no significant effect on the PI, meaning that they underestimate the risk of purchasing LM. The results also show that when explaining the purchase intention of LM, the effect of ‘trust in ISs’ was higher than that of their perceived ‘trust in the product (LM)’ and perceived knowledge.