Sometimes, I find difficult in lose weight. Besides doing exercises, are there any foods that help fat-burning process faster?
As far as I know, there are no foods that burn fat in any significant amount (Mayo Clinic).
To burn fat, a food would need to have "negative calories," which means less calories than the calories needed to digest that food. Theoretically this is possible, for example, water has zero calories and the process of water drinking and absorption requires some energy, so you would burn some calories just by drinking water. But the amount of calories burnt this way is so small that it does not have any practical meaning.
You may want to think how to decrease food craving:
Try to eat less quick carbs (plain white flour products, potatoes, white rice and sugars - soda, fruit juices) and more foods with insoluble dietary fiber (whole-grain bread and non-starchy vegetables). Avoiding anything sweet completely can greatly help prevent food craving.
Try to avoid/limit calorie-dense foods: cheese, chocolate, oils, nuts.
In short: Try foods that are not sweet, not calorie dense and have some insoluble fiber.