What are your favorite low calorie foods/snacks that you eat daily?

I need some help with my weight loss journey. Currently I am exercising on the treadmill 30 minutes a day but it is my diet that is really hurting me. I am having a hard time staying full throughout the day without eating an excessive amount of calories. I am also drinking a lot of water and staying away from most other liquids such as soda. I would love to hear what some of you eat that is low calorie and also very filling.