Eating food containing added sugars stimulates the release of insulin, which also encourages fat storage. These foods also tend to be void of nutrients but high in calories. Don't, however, substitute these sugar-filled foods with artificially-sweetened foods. You may save calories initially, but research suggests that people compensate by consuming more calories later on. Also, there's some evidence that artificial sweeteners (especially sugar alcohols) may also blood sugar levels much the way that sugars do.
Those last 5 lbs. can be tough! I agree with Carolyn. Limit sugary foods and alcohol and fill yourself up with fruits, vegetables, lean protein, whole grains and water. Limit sugary and highly processed foods and focus on fresh and natural foods. Also, eating fat is ok! We all need fat in our diets, but it should come mainly from healthy (unsaturated) fats that are found in olive oil, canola oil, avocado, nuts and fatty-fish. Healthy fats in moderation can help burn that belly fat.