At 57 years old I'd say it IS possible to lose wieght and keep it off.
I know my problem started when I got married to my wife,...instead of serving a plate-full at the dinner table she would lay down several trays to which me and the kids were to help ourselves ( buffet style). Now our kids are not big eaters and I certainly wont see food going to waste,..so......

I went on a diet a year or so ago,... surgeon doing my small hernia op says it would be easier for him if I lost a bit weight off my belly (cheeky git).... so I went on a strict diet with my wife too,.. had coconut vinegar on about everything, salads, fish, chicken,...just kept off the tatties, rice or pasta.... I lost 21 k in the space of 4 months (yes I did) lol,.... and presented myself for my operation where the surgeon praised my efforts.
I did manage to keep the weight off for long enough, but my cravings for my wife's buffet style dinners won me over.
Going out to visit her family again in October so the diet will start again this weekend (we have an Indian meal booked for Friday)..

Jonny