French fried potatoes are the most fattening food Americans eat due to vegetable oils breaking down into the obesogenic toxin HNE during frying.

“and it's probably why one of the more interesting epidemiological studies that I've ever found found that the most fattening food that Americans eat by a huge you know by six or seven fold is french fried potatoes and one of the things that happens to the vegetable oils when you fry anything in it but particularly potatoes is that it breaks down into this obesogenic toxin hne”

“there's actually studies on hne in french fries in french fries in all fry any fried food that's you know where you're frying linoleic acid it's going to break down into hne and other toxins and you know some of them are obesogenic some of them are thought to be carcinogenic”