If you are trying to make healthier food choices or easing into working out more, try and hang with friends who share similar goals and attitudes. You'll feel even better about what you're doing for yourself when someone else shares that enthusiasm. Tell your fitness junkie friend to ring you up whenever they're running next, or invite your health conscious coworker for a dinner at a nice veg restaurant in your area.
That being said, we obviously have friends who are not so like-minded who we can't turn our back on. It's unrealistic to think you can make everyone see the world through your vision. I find the best way to motivate friends to be healthier is to show them how much good it does for you. Pushing beliefs down people's throats is not going to make them appreciate or respect what you have to say, no matter how true it is! Just do your thing, and next time your beer gut bud is trying to get you to order another pitcher just casually say you're doing OK, and maybe he'll decide he wants to cut back on the brews too.
I recently had a lot of eye-opening discussions with people I used to hang out with, realizing they are stuck in their alcohol-fueled, smoke filled lifestyles and are absolutely not contributing positivity to my life. It sucked to think I don't want them in my life anymore, but at the end of the day you're number one. And real friends support each others goals. Above is a photo of myself and a vegan gal pal at a potluck she threw. It felt great talking and eating with like-minded individuals. So inspiring!
So get out there and motivate a buddy to be the best they can be or be motivated by someone in your own life!