I suggest you do more chest push-ups, upward oblique push-ups (hands high and feet low), downward oblique push-ups (hands high and feet low), elbow push-ups (elbows attached to your sides), pull-ups and arms bent on the parallel bars. You can also hold a proper amount of heavy objects (you can take a large bottle of mineral water or others without dumbbells) to do supine flying birds, prone flying birds and supine pressing; Choose three movements at a time, and do three groups each, each group 10- 15 times. Rest between groups 1-2 minutes. Pay attention to relaxing the chest muscles after practice!
Note: Push-ups should be shoulder width when both hands are on the ground. The distance of lifting feet is generally within 50 cm. Choose the height that suits you!
Abdominal suggestions: sit-ups, supine belly roll-ups (the upper body is flat, legs are placed in front of the abdomen), leg-lifting sit-ups (feet are placed on the stool), supine at both ends (lying flat, the upper body and legs are raised at the same time), prone sit-ups (lying flat below the waist, the upper body is raised), prone sit-ups at both ends (lying flat, the upper body and legs are raised at the same time), and lying on the side. Choose three movements at a time, and do three groups each, each group 12- 15 times. Rest between groups 1-2 minutes. Pay attention to relaxing abdominal muscles after practice!
Note: it is difficult to lose the abdomen, especially if you practice at home, you must stick to it; Exercise at least 5 days a week and take a proper rest for one or two days (at least one day off to give muscles a buffer time)!
As for diet, I suggest that you eat more protein and carbohydrate-rich foods, such as milk or yogurt, eggs (you can eat more protein, up to two yolks a day), bananas, lean meat, beef, fish or seafood, and eat more vegetables and fruits (apples, oranges, grapes and the like), which will have the best effect!