I did two decades of Crisis intervention among my many job roles. Always stuck to a healthy diet. Agreed its harder with kids and family if they don't want to. I put a priority on food, as healthy fuel.
I live in Millwoods and so source out a lot of places that have decent quality Fruit and Veggies. I was going to places like H & W and Alices Produce before almost anybody was. Both reasonable places. Alices is a small shop with pretty amazing prices. He almost always beats prices of any other suppliers. The Real Canadian Food warehouse on 99st and approx 73ave is another winner for food, veggies, fruit or meat prices. its where a lot of the vendors or small restaurant owners go to. You get better values there than anywhere.
We run a good sized garden here and two freezers. Do some canning as well. Everything cuts down food costs.
What I find critical, to induce people (and single people to cook more) is learning recipes that are freezable. Stuff like soups, Chili, stews, casseroles, most of these you can freeze. So that if cooking for one is a problem then batch cook and just thaw is a good solution so that you don't feel like you are wasting all that effort just for one person. Don't cheap out on the freezerware. Tupperware or other good portion containers freeze well. I like sizes that you can easily fit into a pot for when reheating.
I'm married and almost always do all the cooking. I've always loved cooking. When I was working fulltime and more we would share the cooking load more, but now retired and doing probably 90% of cooking. heh. we both prefer my cooking.
last thing. Always label what goes into the freezer. What it is(food looks much different frozen), when it was prepared, and have a mix of stuff in there that you can take out for variety. If you don't live near a store just go to a place like the Real Canadian warehouse I mentioned and get a lot of stuff and do a cookathon. Prepare several batch meals, use a lot of stuff up, freeze it, then you have it. EVERY meal you make yourself is guaranteed to be better than any TV dinner or frozen meal from a store. Better than any fastfood.
cheers