We describe a Aspect-based Sentiment Analysis platform based on Food ontology structure performed on over than 26 million food-related tweets. Sentiment distribution on food aspects and sub-aspects are explored to find out the public opinions towards each aspect and sub-aspect of food on Twitter. The sentiment contribution of each aspect to the global sentiment of the post is also analyzed to reveal the importance of each aspect to food on Twitter. Results show that sentiment analysis on Twitter uncover some interesting insights about the public opinions towards food, which is helpful to online marketing. Some ongoing work also introduce geo-information of each post, so as to reveal the geo-distribution of public opinions about healthy life styles inside the area of Montreal.