I’m a couple years older than you and dropped 31kg over the course of 12 months with a combo of 16/8 fasting, 3 liters of water a day, keto, proper macros, and 5 day per week alternating lifting and cardio work days.

The loose skin is there (but quite minimal) because I was constantly working on body toning in order to minimize it. I learned this combination from guys who do long cutting sessions in bodybuilding.

What I’ve learned from myself and others who have done this: Your results will vary based on genetics mixed with your dedication to keep toned and minimize muscle loss: but in a nutshell, with that kind of loss at your age, you will have definitely have some loose skin