Your weight is still healthy, so you will gain something by strengthening your exercise. Aerobic one hour is equivalent to walking 10,000 steps, which can consume about 300 calories. However, we must pay attention to eating less and try not to eat dinner. If you are really hungry, have some fruit. Recommend cucumber, tomato and lettuce. Low calorie, don't be too greasy for lunch. If you exercise at night 1 hour, you will probably gain 3-5 Jin a month according to your situation, but you must insist on it and don't eat snacks. This will make you give up all your efforts. You don't need to be as thin as 45 kg, it will be too thin, and 50 kg is the best.