I really do not recommend low-carbohydrate diets. They are usually lacking in complex carbs, vitamins, and minerals, and people on these diets end up feeling very tired. This can be very counterproductive as you need the energy to exercise which is extremely important when you are trying to lose weight.
Complex carbohydrates are whole-grain foods such as whole-grain bread, oatmeal, brown rice, potatoes, oat bran, and pasta. Unlike candy, soda, and cookies, which result in a quick rush of blood sugar and then the ultimate crash, complex carbs provide a slow release of insulin in the blood which stabilizes your blood sugar and provides a good source of healthy stable energy.
When you lose weight from low-carb diets, much of it is from water loss. These diets are difficult to sustain for long periods of time and most people cannot maintain eating this way, so they end up gaining all the weight back again. I eat a lot of complex carbs. I have some with every meal. I also exercise a lot so I need the energy and without complex carbs, I don't think I could maintain the level of fitness that I am used to.