I'm 5'9, 158 pounds, I used to weigh 190-195 pounds basically most of my life, until a few years ago when I decided to change my habits and routine.
Running 2 days a week.
Gym 2-3 days a week.
5-6 small meals a day, including fruits and vegetables.
Reduced quantity of meat, I eat meat around 2-3 times a week.
High protein, low carb ( oats for breakfast, wild rice for lunch, mostly )
Multivitamins + Fish oil + Whey protein
What I do at the gym:
Squats
Bench presses
Bent-Over Rows
Overhead Barbell Presses
Deadlifts
Barbell Curls
Pull ups
Dips
I've been able to keep my weight constant over the years, and even had a visible six pack around 80% of the time.
I'm posting this because it worked for me and it's pretty basic.