Seasonal food refers to the times of year when the harvest or the flavour of a given type of food is at its peak. This is usually the time when the item is harvested, with some exceptions; an example being sweet potatoes which are best eaten quite a while after harvest. It also appeals to people who prefer a low carbon diet that reduces the greenhouse gas emissions resulting from food consumption (Food miles). Macrobiotic diets emphasise eating locally grown foods that are in season.