Care about carbon emission and sustainable living? Here is one diet that you can try out. The 100 mile diet has acquired quite a following in certain parts of the west. No, it is not a magic formula for reducing weight. The diet refers to the buying and eating of food that has been grown, manufactured or produced entirely within a 100 mile radius. In the US, some foods travel as much as 1,500 miles impacting environment and farming practices. The 100 mile diet evolved out of the necessity to reduce carbon emission when food is transported over long distances.