Why are carbohydrates the devil for some people?

(Bob Ross! He is awesome! Afro on fleek!)
Carbohydrates are carbs, the unhealthy stuff in children's cereal, teenager's gum, and adult's... whatever. If you are on a diet, most people go for a calorie-free diet. But, actually, you should go for a carbohydrate-free diet. Why? Because without the calories you feel so unenergized! And without the carbs, you will definitely see a difference. You will be much more energetic and ready for school and work.

Is there any answer choices?

Biochemistry, it deals with the chemical constitution, the breakdown and the synthesis of plant and animal products.