I'll pitch in with my usual advice. But first I'll say...don't expect to weigh what you did 40 odd years ago. It's an unrealistic goal for the most part.
I'd say don't eat less...eat differently. Cut out starchy carbs...bread and grains*, rice, pasta, beer. Eat plenty of good protein such as chicken, oily fish, eggs, some dairy, leafy green veg...maybe some nuts or seeds. Use olive oil, or a bit of butter...actually better than fake vegetable spreads. Get creative and use herbs of spices for variety. Eat 2 or 3 meals a day...eat until you are satisfied.
* think of it this way, grains are fed to livestock to fatten them up.
As others say, drink when you are thirsty.