In view of this situation, if there is nothing abnormal in your body, it may be that you have strengthened your nutrition, eaten regularly and started to gain weight slowly.
As the saying goes, exercise more and eat more.
It may also lead to weight gain, because your exercise is not proportional to your food intake. For example, you just exercised a little today and burned a little calories. When you feel tired and your friends are hungry, you eat and eat, which leads to obesity. More importantly, don't eat foods with high salt and heavy oil, which will lock in water and accelerate the transformation of sugar in the body.
These are all possible reasons for your weight change.