Food waste was the biggest contributor of waste amount 40,8% in Indonesia, according to Sistem Informasi Pengelolaan Sampah Nasional. Food waste also has a significant impact on the environment due to its greenhouse gas emissions. However, food waste is still uncommon in public discourse. Gifood is the social community established to begin action on food waste and sustainable consumption campaigns, especially for young consumers in Yogyakarta. The research employed the Theory of Planned Behavior as a theoretical framework, and used a quantitative method to gather data a year (2019)(2020). 135 Gifood's social media followers were randomly selected as study samples. By using simple regression analysis, this research found that sustainable consumption messages had a statistically significant effect on attitude (t value 3,871 > t table 1,656, p 0,00 < 0,05), subjective norm (t value 4,247 > t table 1,656, p 0,00 < 0,05), and perceived control (t value 9,098 > t table 1,656, p 0,00 < 0,05). The results also showed that using a multiple regression analysis, the subjective norm and perceived control variables can explain 59.6% of the variation in the intention variable. The subjective norm had most influence (β = 0,443) and followed by perceived control (β = 0,315). While attitude had not statistically significant. The study suggests that in order to promote sustainable consumption more effectively, factors such as normative beliefs, motivation to comply with others' opinions, and perceived control should be taken into consideration.