100 gm of cooked rice has approximately 500 calories, whereas 100 gm of flour has 400 calories -both are high sources of carbohydrates and eating them would mean more fat. Carbohydrates get converted to sugars and if unused by the body get stored as fat. If you do want to eat chapati use multi grain flour so you get lots of dietary fiber. Rice has no dietary fiber unless it is brown or red rice. Then it is very nutritious. Chapati has more fat than calories while rice provides more calories and contains less fat. If you need to eat rice or chapati, limit your portion of rice to minimal and eat one chapati only.