modifying life to get healthy

I am ready to start, I think.  I am trying to help my family eat healthier and also get on a better track especially now that my husband was recently diagnosed with diabetes.  Our biggest problem is eating regularly.  When we eat it is almost always 2 or 3 meals including snacks a day.  I'm sure that we are totally in fat-storage mode with our bodies, but trying to come up with healthy meals for a family of 8 is not so easy. (especially with food allergies and some picky eaters.)  Our family also has other health problems. Multiple sclerosis for 2 adults and kidney disease for 1 adult and the kids are mostly under weight because my daughter doesn't like most meat products and my son is on ADHD medication which takes away his appetite.  My two older boys have the teen/ pre-teen appetites and would eat us out of house and home, but our budget can't afford that. I hate to prepare separate meals, but I have to be able to get some things out there for everyone.  If you have ideas and suggestions, please feel free to offer them.