Carbohydrates are the main source of energy to the brain, kidneys and the central nervous system. Potatoes are starchy carbohydrates that help the digestive system to breakdown carbohydrate into glucose. The pancreas is responsible for the secretion of insulin that assists in the migration of glucose from the blood to the cell.
Weight gain as a result of potatoes is only possible if you over consumption of calories found in the potatoes more than your body is able to burn. We cannot therefore conclude that we have weight gain potatoes as minimal consumption will not result to bulking up.
Potatoes of course should not miss in the diet of a skinny person working to gain more weight. Carbohydrates are the preferred fuel source by the body. Carbs are stored in your muscle tissues and liver as glycogen. When your muscles are in need of energy, after exhausting the supply of ATP, the body initiates glycolysis. The latter is the process the body converts sugar and carbs into ATP and subsequent energy.
For you to gain weight you have to up your carbohydrate intake and the result is muscle build up.
Weight gain potatoes are essential as they help the body get the required healthy dose of carbohydrates in the body. Some of the carbohydrates like processed ones should be taken in small doses as they may have side effects on the user. Too much potatoes intake will off-course lead to weight gain.