Forgetting the delicious taste of shnacks like Doritoes, living on just potatoes is probably better for you health wise... especially if they're cold...
"A small but significant portion of this starch is resistant to digestion by enzymes in the stomach and small intestine, and so reaches the large intestine essentially intact. This resistant starch is considered to have similar physiological effects and health benefits as fiber: It provides bulk, offers protection against colon cancer, improves glucose tolerance and insulin sensitivity, lowers plasma cholesterol and triglyceride concentrations, increases satiety, and possibly even reduces fat storage.[54][55][56] The amount of resistant starch in potatoes depends much on preparation methods. Cooking and then cooling potatoes significantly increased resistant starch." (Wiki)
Engels compared them with iron for their "historically revolutionary role" apparently. I'm sure he was well versed in his chip supper