Hehe. Sorry about the derailment.
I think despite the disagreement about all the rest - we all agree that talking from a neutral position would be the best way to handle it.
I think even though someone isn't normally "that type of person", feeling insecure or scared can make them do things that aren't part of their normal makeup. It does sound like your wife is scared about these changes.
I'm gonna ramble for a minute: I actually lost two really good friends when I changed my life and started losing weight. I've always been a "foodie" - I love to cook, I love to try new things, and I love to eat. And I'm not the type of person to use "low fat" or "diet" foods. I still don't in my newer, healthier lifestyle - I've just learned that I don't have to slather my bread with butter - I can have a taste.

But .. anyway.
I had two friendships that revolved around food. We all loved to cook. We all loved to eat. We were all fat. Going out on a Friday or a Saturday night meant going to the pub and ordering a double order of blue cheese chips and a burger and drinking Guinness. Getting together on a Sunday afternoon meant cooking out - chips, dips, salsa, burgers and dogs on the grill, potato salad slathered in mayo, etc. Meeting after a stressful day at work for a drink was not just a glass of wine or a cocktail - it was always margaritas and chips and queso at the local Mexican place. I shudder to think of how many calories I must have put away with these friends.
When I started losing weight and eating healthier, that had to change. I couldn't continue to do those things. I would still go out with them, but I wouldn't eat what they ate. And ... to be honest .. I had to start saying no to going out because I couldn't eat bar food 3-4 times a week and lose weight.
At first it was ok - they'd tease me but also encourage me. They'd help me find things on the menu that were healthy. And then I started losing weight. I dropped 30 lbs. I went down 3 pant sizes. My one girlfriend who I used to go clothes shopping with (usually after a breakfast at IHOP

) - we couldn't shop together any more because she was still buying things at Lane Bryant and I couldn't wear anything there any more. I always went with her and helped her pick things out, but when we went into the Gap or Old Navy or any other store that didn't have plus-sized clothing, I could tell she was hurt and angry. And it became not so much fun for us to shop together any more.
Anyway ... long story short, these two friends and I drifted away. Eventually the one woman just stopped returning my calls and we haven't seen each other in over a year. It hurt a lot ... but my therapist pointed out that probably from her point of view, I'd abandoned our friendship. Our friendship that revolved around food and eating and being able to shop together and not feel bad ... suddenly didn't revolve around those things any more.
The other friend I still talk to, but we don't do anything together much any more because I won't go spend an evening drinking and eating junk.
All of that to say, I think it's harder when it's your spouse involved - because she can't just end the friendship or pull back or not invite you out to eat anymore. She can see all these changes in you and even if she's never been "that type" before, she's probably reacting out of fear. Up until now your relationship in part has been based on shared food experiences. Going out and sharing an appetizer and dessert is kinda romantic, you know? Sharing food is intimate - you don't do it with strangers for the most part. And suddenly you're not doing that any more. In some ways, that could be interpreted as a form of rejection.
It's scary when someone you love or care about makes huge changes in their lives. It's why friendships end when someone gets married or has a kid or becomes the first in the group to get a real job out of college - priorities change and it takes real work to maintain ties when there's a change of priorities.
I dunno... maybe I'm babbling here. But I can see both sides. And I do think that talking it out in a neutral location and reassuring your wife that you really love her and that no matter what she eats or what you eat .. you're still going to love her - I think that would help.
