The potato is a starchy food, a tuber of the plant Solanum tuberosum and is a root vegetable native to the Americas.
https://en.wikipedia.org/wiki/Potato#Nutrition
a typical raw potato is 79% water, 17% carbohydrates (88% is starch), 2% protein, and contains negligible fat (see table). In a 100-gram (3+1⁄2 oz) portion, raw potato provides 322 kilojoules (77 kilocalories) of food energy and is a rich source of vitamin B6
 and 
vitamin C  (23% and 24% of the Daily Value , respectively), with no other vitamins or minerals in significant amount (see table). The potato is rarely eaten raw because raw potato starch is poorly digested by humans.[65|65]
 When a potato is baked, its contents of vitamin B6 and vitamin C decline notably, while there is little significant change in the amount of other nutrients.
[66|66]