Potatoes are not healthy to even the Incas. 
Acrlyamides inherent in potatoes insured a very short life span due to very high cancer rates.
The high glycemic value of this staple also produced very high rates of heart disease.
The lectins contained in these tubers (that draw vitamin A out of the body) resulted in the highest blindness rates in the world.
When the Inca conquered new people the surrender ceremony consisted of forcing their new slaves to eat potatoes.
Potatoes are, indeed, very profitable!
They are what financed McDonald's rapid growth.
Even today the beef is a "lost leader" ( sold at a loss)  to sell fries and corn fructose soda.
Thus McDonald's a very good place for bargain hamburgers ( I always feed the buns to the birds).
 
The hamburger ( mostly grass-fed imported beef) sold in fast food restaurants is also higher in Omega 3 fatty acids that the ground beef sold in super markets.
I'm lovin It!
 
Ray Audette
NeanderThin
The English did the same to the Irish just as the Romans used bread and wine to profitably enslave their subjects (thank you Dominus).