I have been on weight-loss journeys, yes more than once. The last one stuck but I have to remain disciplined. The key is not the amount you take but the amount you burn. Carbs are required, the amount depends on how much your body needs. I have to consume a carb heavy diet because my work depends both on physical and mental activity. I eat for two people, yet maintaining a lean figure. I feel sluggish only when I don't get enough physical or mental exercise.