Go to the supermarket or the farmers market together! Take a cooking glass, go through a cooking/recipe magazine (Rachel Ray has some simple ones but there are others). Go to the library and take out a few cookbooks, or look to see if there is a magazine exchange. Ours has one (bring a mag, take home a mag). Get inspired by the beautiful photos of healthy food and learn how simple it is to prepare.
Why are you in charge of planning all of his meals? He has to be invested in this too! Does he at least grill? Have him learn to marinate and grill salmon, fresh veggies and more. We do a TON of that, and I find if we do the planning, prep and cooking together, we enjoy the time with each other as well as the finished product!
Invite people over to share your grilled or kitchen magic with them. Nothing like socializing to make it fun! Just resist the urge to serve a ton of unhealthy appetizers and 3 bottles of wine plus a bunch of desserts!
Does he have a gym membership? If not, can you get one? Usually they give a couple of free sessions with personal trainers who will help him set up a manageable routine, write it out on a sheet that he takes with him from machine to machine. They are good at establishing goals, and making him accountable to someone. Sorry, but I don't think a lot of people are as accountable to themselves or to their spouses as they are to a third party! And I go to a regular class of people who are all friends now - at least gym friends - and we call each other if someone misses too many sessions!
I also think goals can't just be "pounds lost" - they can be "miles walked" or "weights increased" or "inches lost". Most people plateau during weight loss regimens, and muscle weighs more than fat, so a pure "pounds lost" goal is defeating.
Will he use a treadmill at the gym? Get him a book rack that holds books open while he's walking. Get him a couple of books he's been meaning to read but "just doesn't have time for" - 30-40 minutes on a treadmill is a GREAT time to read.
Great music on his phone and some comfortable ear buds make it pleasant to listen to a great playlist while walking. He's just not going to lose weight based on diet alone. He has to get up, get out, get moving, get away from the sugar sources. He has to learn that he doesn't "reward" himself for a workout by going for ice cream.