Fat has 9 calories per gram. Carbohydrates and protein have 4. The problem is that we strip all the fiber away from the carbs we eat and this causes all kind of problems including making them less satiating. Getting fat eating whole carbs is quite difficult. Refined carbs and sugar are bad but the idea that all carbs are bad is simplistic and wrong.

Legumes in particular are extremely filling: https://www.azumio.com/blog/nutrition/beans-skinny-food