If you gain muscle, it is normal to gain weight. Long-term strength training, muscle dimension increases, and weight naturally increases, but this is not the same as being fat. Strong, not fat, to be exact.
If you are losing weight, there is a problem.
First of all, is there anything wrong with your exercise style? Aerobic exercise, such as running and skipping rope, is the best way to lose weight.
Secondly, we must pay attention to the convenience of diet, try to eat light food, eat more vegetables and eat less greasy things.