Healthy Habit Hack @ HKU is an initiative to promote healthy lifestyles, hence better health and well-being (SDG3), through small habit changes in the HKU campus. The project starts by encouraging the consumption of more nutritious options among packaged foods. We surveyed the nutrient contents and healthy ratings of various packaged food items being sold in the vending machines on campus to give some familiar examples for the HKU community. Findings are revealed to the university community via our Instagram account (healthyhabithack_hku) to serve as a useful guidance for them to make wise choices available on campus. We also empower the university community to identify the nutritional values of packaged food items on their own by introducing them with a pre-existing app (FoodSwitch). Not only can users check whether an item is healthy or not, they can also receive recommendations from the app database for better options. In turn, if the data of an item is not found in the app, users can contribute by inputting simple values from the package to help build up the database. Besides, we advocate for real changes in the campus for a better environment promoting healthy lifestyles by reporting the findings and recommendations to the relevant authority in the hope of improvements. Overall, the project will benefit all parties and we hope Healthy Habit Hack @ HKU will resolve more dimensions and widen its coverage in the future.