When you are in your caloric deficit your organism needs to burn the fat to use it as an emergency energy source and that is the only non-pharmacological way to get thiner. On the other hand if you eat more calories than you need you can build your muscles but also gain fat and it always goes together. That is the mistery standing behind your "diet". You use more energy than you deliver to your body from the food. "The only secret is that you have to keep your carbohydrate intake below 50 grams a day" I'm sorry to say so but it is a lie and not everyone will lose weight feeding themselves the same way you did. How much calories per day you need depends on your weight, height, age and phisical activity, please keep that in mind because burning fat is not actually associated just with the ammount of carbohydrates.