I tried manipulating macro-nutrients for a while, but I had to conclude that protein, fat, and carbohydrates all have an important role to play in our diets. The main problem with a food like donuts is that the combination of fat, starch, and sugar, with very little protein, can easily lead to excess calorie consumption. Not that I don’t eat donuts sometimes!
It would be surprising if a combination of carbs and fat were intrinsically damaging, because the overwhelming majority of cultures consume foods with both macros. Think bread and butter, rice fried with lard, pasta and cheese, tortillas and fatty meat, etc., etc., etc.
If I am honest with myself, I know that I will never follow a diet that deprives me of either fat or carbs. I love them both, and I love them in combination with one another. Any diet that eliminated one would be completely unsustainable for me, and believe me, I’ve tried both! Any diet that creates strong feelings of deprivation isn’t worth much, because no one will be able to keep it up without complete obsession.
Excess calories are what make us fat, not perfectly normal combinations of foods.