No, sugar is not bad ,IF you are taking it in a limited quantity. If you limit it to 2-3 tsp per day, then it is not bad. 1 tsp is 20 calories so 2 to 3 tsp will be 60 calories only. Therefore do not replace sugar with the substitutes which can be harmful for health but limit the consumption of sugar both visible & hidden sugar. Hidden sugar are there in biscuits,bread,rusk etc.