How we define waste is part of the problem. What is 'waste' to one person may be a valuable food source for another. Establishing efficient connectons between the food services industry and people who would value cheap or free food (students, the urban poor, the elderly) or community gardens requiring compost, local animal feed users needing vegetable peelings etc is one way to reduce waste from landfill.
Composting food waste, collected kerbside from residences and street-side as part of the city's waste collection service is another important way to keep it out of the 'garbage'. The local authority needs to have clear goals for the food 'waste' to become plant food for the next crop of fruit and vegetables. It has to be a self sustaining system, so that the cost of collection is met by the production and delivery of product back into the community.
However, lack of knowledge of how to handle food / how to prepare leftovers as a tasty nutritious meal, is a big part of the problem, within the domestic setting, as well as within the food industry. Yes, use-by dates are there to protect us, but we need to know when they are a guide and when they must be adhered to. Cooking shows and recipe-based blogs are popular. They could do more to encourage a sustainable lifestyle if they show cased low cost foods, recipes for 'left overs', and garden to table initiatives.