Is it possible to lose belly fat caused by aging?

In the past, I could lose weight quickly with just a little diet control and exercise, but lately, I am worried because it seems like my belly fat is particularly hard to lose even when I diet using the same methods. I have accumulated a lot of fat around my waist and lower abdomen, and it is frustrating because even though my weight has decreased slightly, my belly hasn't changed much.

People around me say that as we get older, our basal metabolic rate drops and muscle mass decreases, making it easier to gain belly fat and harder to lose. Is it really true that age-related weight gain is harder to lose than with a regular diet? I am also curious if doing only cardio like I used to is ineffective, or if I need to do more strength training.

I have been eating less than usual, but since there hasn't been as much change as I expected, I am worried that I might need to increase my protein intake or change my lifestyle. I have heard that lack of sleep and stress also affect belly fat, and I would like to know if there is actually a correlation.