After 7 months of Paleo-Primal-VLC Primal my wife, whose favorite foods include macaroni and cheese, papa john's pizza, mashed potatoes/potato chips, and "fruit flavored" candy (all washed down with diet coke of course) has begun cooking meals like jambalaya (beef, chicken, shrimp, and okra with a tomato base), eating pork cracklins, drinking pastured half/half with coffee (vs her old diet coke), having bacon and eggs for breakfast, etc.
She still indulges in her old "favorites" but the balance is definitely shifting.
The major breakthrough came when I stopped trying to change/judge her and just focused on being really happy with how I am eating. If I would make a paleo/primal meal, I'd offer to make it for her as well, and would make a point to incorporate things that she does like (such as this pulled pork cooked in coconut water).
If she says, "Oh, I want pizza so bad!" I don't frown, make a comment, or give her a hard time. I'll simply smile and acknowledge that I heard her with a pleasant "yeah" and nod of the head.
Resisting someone else just makes them push back harder. If you create a welcoming, inviting atmosphere, enjoy and are content with what you are doing for yourself, and let go of the need to control others, you might be surprised.
Of course, this is coming from someone who took about 5 years to come to this conclusion, but hopefully you're not as stubborn as I am!