But you will look good in tight clothes like a heroin-chic Calvin Klein model.
What works for me, sort of, is to just be mindful of total calories taken in throughout the day. It's easy to lose track of how much you eat as you work and drive around and snack and work and snack and drink and eat and next thing you know, you are averaging way over your daily recommended or target calories.
I read labels religiously for calorie content and keep a running tally in my head for a rough estimate of my caloric consumption. If I work out that day, I allow myself a bit of wiggle room, but here's the bottom line, no matter what you do or don't do or subscribe to from everyone else's advice:
You eat more, you will put on more weight, simple as that. You can work out all you want and be as healthy as you want and blah blah blah but if you are eating 5k calories a day of healthy food, you are still going to put on weight compared to a guy who eats 2k calories comprised only of bacon and burgers and beer, all else being equal.
I'm older than a lot of you and I've managed to keep within two inches of my waist size from high school/college and that's only because I was a really tiny dude back then because I keep mindful of my caloric intake and I lift weights to maintain muscle mass.
I am not as worried about overall weight as long as my size and musclature is intact. You work out more, you will put on mass because muscle is denser than fat.
At my peak, I was 25 pounds heavier than my skinniest weight in high school, but was the same waist size. Go figure. My muscles were huge though so that explains a lot of the mass.