The dynamics of weight loss or weight gain are very simple: generally speaking, to lose weight, it is necessary to consume fewer calories than we use for our day-to-day activities. The lack of calories will result in fat loss, which the body will use to meet energy needs.
Conversely, if you consume more calories than you need to support your body, the calorie excess will be stored in the body in the form of fat. Put simply: you’re going to get fat.