To get a flat tummy, you must drink a lot of water. What I do, I drink two glasses of cold water on an empty stomach every day 45 minutes before I eat breakfast. I have done this for many years. I drink lots of water during the day, and also while I eat. I drink a glass of cold water 20-30 minutes before I eat a meal, lunch, or supper. Then I eat as usual. I eat everything except sugar. Occasionally I eat sweet things.
I tried this with my husband. Every morning before we drink coffee, we drink cold water. He never did that before. Now he lost his belly fat and also has a flat stomach, without doing any exercise.
Try to drink a lot of water and then you can eat normally. You will see the results soon! And also be more active lol. I don’t go to the gym, but I move a lot. Going up and down the stairs in my home or taking a walk outside.