Not a new idea

Taken from Taubes:

Farinaceous and vegetable foods are fattening, and saccharine matters are especially so…. In sugar-growing countries the negroes and cattle employed on the plantations grow remarkably stout while the cane is being gathered and the sugar extracted. During this harvest the saccharine juices are freely consumed; but when the season is over, the superabundant adipose tissue is gradually lost.
THOMAS HAWKES TANNER, The Practice of Medicine, 1869

Starch, carbs and sugar make you fat. They're all the same thing, anyway. We've known this for a long time. Note there's no mention of dietary fat, or calories consumed and burned off.