French fries, donuts, and other deep fried or packaged and highly processed foods are often called “carbs” but most of the calories are from high PUFA seed oils, not carbs.

I do think high PUFA seed oils are often an issue there… they cause damage to the liver, and mitochondria, such that people feel worse, and have less energy- which in turn promotes both inactivity, and overeating. There is lots of good data on various species of lab animals getting NAFLD and metabolic diseases when swapping out MUFA and SFA for PUFA.