There is absolutely NOTHING magical about not eating carbs after 6 pm, or before bed.....if your daily caloric are below what your body needs to maintain itself for 24 hours, you will lose weight regardless of when you eat them.....if it is more that what your body uses in 24 hours, you will gain weight regardless of when you eat them....
On a low carb diet, one could argue that eating carbs before bed would spike insulin for no reason......i diasgree with this....if you eat 100 g of carbs a day, or 20 g of carbs per day, as long as you stay with that number of carbs you will get the desired effect regardless of when you eat them......
People stres far too much about the role of insulin in carb cutting diets...while insulin halters fat loss, the reason low carb diets work is that by depriving your body of carbs you are emptying your muscle glycogen levels, and then your body will tap into body fat for energy.....the manipulation of insulin is a factor, but even a meal of 50 g of carbs wouldn't raise insulin for very long....
Insulin is an issue in fat loss, but even 200 g of carbs a day there are numerous times of the day when your insulin levels will not be high.......bottom line: stick to your carb limit (what ever it is, 20 g or 200 g), eat them with a post workout meal and when ever else you must, that includes before bed or at night.