By making a small change to your diet you can cause a hormonal change which leads to long-term fat loss.
Replace starchy carbohydrates and sugars such as bread, pasta, potatoes, cakes and pastries with non-starchy carbohydrates (certain fruit & vegetables) and your body will react by burning fat instead of storing fat. Include healthy fats such as avocado, fish, coconut oil nuts and seeds and add some good quality protein (Greek yogurt, eggs etc) and you have a high quality calorie diet instead of a low quality calorie diet which leads to fat storage.
Low fat diets and low calorie diets can lead to lack of nutrients and fat gain because your body thinks it is being starved. Low calorie diets cause havoc with your metabolism. The key, is to prevent hunger with good quality nutrients that satisfy and nourish your body.