How grams of carbohydrates a day to lose weight?

Not how many carbs, how many calories. A pound of fat contains roughly 3200 calories. You want to lose 20 pounds of fat, which means you'll need to create a caloric deficit of (3200*20) 64000 calories- which works out to a deficit of 3050 calories per day. That means you need to burn 3050 more calories than you take in, everyday, for the next 3 weeks to lose 20 pounds of fat. That's not happening. Instead of creating impossible lofty goals to be accomplished in an unbelievably short amount of time, how about creating realistic ones that you can maintain for life? Any healthy diet is one that you will have to follow for the rest of your life if you want to continue seeing benefits.