This study analyzes the implementation of sustainable practices in five households over a five-month period, focusing on three axes: waste separation, use of reusable bags, and responsible consumption. Baseline and final surveys were administered, monthly follow-ups were conducted, and an economic exercise compared the cost of “non-responsible” purchasing options versus more sustainable alternatives. Results show that four out of five families reduced their use of single-use plastic bags to near zero, decreased weekly household waste, and increased waste separation. In addition, all families recorded economic savings associated with responsible consumption: the September analysis indicates an average saving of approximately 28–30% in the categories assessed. This suggests that consumption choices aligned with SDG 12 involve not only a lower environmental impact, but also household economic efficiency. Finally, we propose that accounting can function as a pedagogical tool: quantifying waste avoided and money saved supports informed household decision-making and links day-to-day behavior with environmental and financial consequences.

Food waste in the home represents an environmental and economic issue, directly linked to inefficient resource use and the emission of polluting gases. This study aimed to analyze how domestic consumption practices impact food waste and to evaluate the effectiveness of management and accounting tools as educational mechanisms for its reduction. A domestic management guide was applied in a selected household, focused on improving food planning, control, and utilization. The results showed a significant reduction in both the volume and value of waste. Economic incentives proved to be more effective than environmental or social ones in modifying behavior. A widespread lack of knowledge regarding expiration dates was also evident, and distortions were identified that stemmed from external factors such as home production and personal preferences. A negative feedback cycle was found, in which poor planning leads to excessive purchases and disorganization, ultimately resulting in involuntary discarding—an outcome that becomes entrenched in the absence of educational intervention. It is concluded that consumer education, combined with accounting and management tools, constitutes a promising pathway to reduce food waste, although it is necessary to expand the sample and strengthen the methodological design to validate the findings.