I need to be careful about what I eat, because I eat a lot (roughly 3000 calories per day). I do Mixed Martial Arts training 3 times a week, and Cardio Kickboxing 6 times a week, and I also have a few sessions of running and bodyweight strength training. After Mixed Martial Arts training yesterday morning, I ate 2 chicken burgers, 2 apples, and a can of tomato beans, with 2 cups of milk, and I wasn't even full. I've tried eating less a few times, but that just resulted in me feeling fatigued and tiring out more easily in kickboxing.
I rarely/never eat pizza/chocolate/soda/etc. Whole wheat bread, chicken, spinach, eggs, yogurt, and apples are foods that I eat pretty much every day. Hell, I've become obsessed with my diet to the point where I have dozens of spreadsheets on my computer detailing what I eat, and how much fat, carbohydrates, and protein I consume.