I agree with Able about the cleanse. I’m not convinced they’re safe for many adults. Try to use lots of herbs and spices and as many different vegetables as you can. The more varied the sources of fibre, the more varied the gut flora can become. Fermented veggies and dairy are good sources of vitamins and bacteria. Clarified butter is great for vitamins too. High in K2 if you can find organic. If you make sure they have a good source of vitamins K2 and D, you’ll save a lot on dental bills in the future.
According to a survey I saw from 2005, Americans got 2/3 of their calories from grains, added sugars and vegetable oils. There are healthy cultures out there who live on high-starch, high-fat and even high (natural) sugar diets, and obesity research trying to pin it on one or the other isn’t doing a very good job. It doesn’t seem like food can be unhealthy unless it’s eaten the way we eat it. Avoiding grains, added sugars and vegetable oils as much as possible is probably a good way to improve anyone’s health if you can’t do anything else.
I saw some guy on a blog saying his 4-year-old son loved 85% cocoa chocolate and pulled a face when he ate milk chocolate because it was too sweet. It’d be awesome if you could stave off their sweet toothes somehow. Berries and heavy cream make a good low-sugar dessert with prebiotics (berries have antifungal compounds that stop them from getting infected by moulds too). I guess it really depends how strict you want to/can be with them.