Angela has a good point about balance. I don't want to scare anyone with that responsibility post! There is a whole world of things I don't know and I agree that trying your best with what you do know is the key. I fear though, health education aside that our culture leans on the trust side instead of the thinking side. I'm not sure I really know many people personally like this I have just seen it culturally. By trust side I mean just going with what you leaned in school as a kid and what you hear on the news. But I want to help change the way you think about food. So you can look at a dish or ingredient objectively and draw a conclusion on it based on more logic then just what you know food wise. Like maybe adding in some ideas about people in other parts of the world, people in other time periods in history, what the food looks like or the ingredients sound like. I was thinking about this today because I was wondering about my own hypocrisy. My son is 2 and a half and I will absolutely not let him have candy. But I will let him share a donut... I was trying to decide tonight... why? I finally realized that to me a donut looks like food. Let's disregard for a moment that they are terrible for you. It is bread, sugar, and chocolate (I'm talking about bakery donuts...not from a package). Okay I can handle those ingredients... I can make that at home if I wanted to. But I cannot make a gummy worm or peppermint candy at home. I have no idea what kind of chemical composition and work made this thing... it doesn't look like food.
In my opionion if you are reading this blog than you probably don't fall into the catagory of people who are acting irresponsibly with thier diet, consequences and all. I also doubt that those reading fall into the category of faithful followers of health trends.
As for:
What health/food change that you have made would you say has made the biggest impact?
Personally, ditching the daily meat and throwing out the milk and all things canned changed my diet, body and health the most. At that time my son wasn't eating solid food so I was mostly eating flat bread sandwhiches, nuts, and steel cut oatmeal. As he started growing into a little boy and requiring breakfast, lunch and dinner I started learning how to use whole wheat flour and honey or agave nectar instead of sugar, to cook things that resemble your average meal type thing. Does that make sense??
So my advice to a busy family. Frozen fruits and veggies I am totally down with. A frozen peach looks and tastes like a peach so I'm okay with that. And get new recipes. I check out cookbooks from the library and I have never had a problem finding "cream of mushroom soup" in a mediterranean, vegetarian or vegan cookbook. The latter two have the most creative recipes and you can always add meat back in! At the risk of sounding like a PBS commercial... Look for these at your local library: How It All Vegan! by Sarah Kramer, Vegan With a Vengence by Isa Chand Moskowitz, The What Would Jesus Eat Cookbook by Don Colbert, and I just returned on that I took a lot of recipes from called The Ethnic Vegetarian but I don't remember who wrote it.

Some normal things made healthy:

Apple Muffins
3/4 cup ww flour
3/4 cup white flour
2 tsp baking powder
1/2 tsp salt
1/2 cup honey
1/2 cup yogurt
2 eggs
1 tsp vanilla
1 1/2 cup chopped apples (like 2 apples)
1/8 cup milled flax seed
1/2 cup olive oil

by the way if you don't have flax seed, up the oil to 3/4 cup.
Combine dry ingredients in one bowl. Combine the rest until creamy in a different bowl. Add the dry until just blended. Fold in apples. Fill tins Bake at 350 for 25 minutes.

Oh here is the perfect pancake recipe...

1 cup whole wheat flour
2 tsp baking powder
1 TBL honey
3 TBl olive oil
1 cup yogurt <-- lately I have been doing half yogurt half water, just because)
2 Large eggs
1/4 tsp salt

Mix together the honey and oil. Add the yogurt and egg - beat a little. Add the dry ingredients. As I learned recently, let the mixture sit for abuot 10 minutes before you start plopping them on the skillet. That lets the gluten develop and you'll have fluffier pancakes.
I usually substitute some millet flax seed instead of some of the oil - it says on the side of the box the ratio.
I also like to mash up a winter squash or sweet potato and add them to the mixture usually with 1/2 TBL more honey and a bit of cinnamon.