How to lose weight once without rebounding? Losing weight is a protracted war, so we must lose weight reasonably and don't go on a diet, which will not only hurt our health but also rebound. So be sure to diet and exercise. The diet here is not not not to eat, but to control the diet and eat less and more meals than usual. For example, if you like snacks and desserts, you must eat less or not eat high-calorie fried food. You can run, jump rope, play badminton and do yoga before going to bed.