If you build more muscle your metabolism will increase, meaning you will burn more calories even at rest.
Anyone wishing to lose fat should cut out the junk and do cardio as well as resistance training.
People often delude themselves that they are the same weight as they were in their twenties. This may be so, but most likely their body composition has changed and weight that used to be muscle is now fat. Hence I would recommend resistance training to everyone, it's use it or lose it folks.
That goes for women, the elderly, everyone.
I can't really answer th OP's question as there is no one answer, but.. reducing calories will give you the quickest short term 'weight' loss.