Sweet potatoes were the main source of nutrition for what was once one of the longest living group of people (one of the "Blue Zones"). Their macronutrient content flies in the face of many people's modern ideas of what nutrition is all about. This food is not only packed with nutrition but it is one of the best weight loss foods for those who need to lose weight. If you are looking for a staple food that is also one of the least allergenic foods on earth then look no further than the humble sweet potato. How can you grow it? What is a good northern variety to grow? And much more.