(2) Keep the portion size small; allow unrestricted additional (small) portions. DO NOT USE EXTRA LARGE DESIGNER DINNERWARE for everyday, anyway. It fucks with everyone. If your larger kids/teenagers want to switch to larger portions/fewer times a day, that's fine, but at least start them out with small/frequent portions.
(3) Do not allow any of the macronutrients to drop to zero (so, nobody is supposed to eat zero-fat, or zero-carbs, or whatever; obviously, if you've got some special medical thing, that overrides).
(4) Establish a "family palate" that runs high-fiber/low-sodium. If you let the restaurant industry define the family palate, you'll sink into the swamp of empty calories faster than you can empty the salt shaker. I'm not saying never eat out; I'm saying when you do eat out, it should taste noticeably different than your usual food, and you should basically prefer your usual food.
(5) Include regular snacks, in addition to "meals".
(6) Make water your normal drink. I'm not saying no coffee, no tea, no soda, no alcohol whatever, but those should be unusual (only in the morning, only in the afternoon, only after 6 p.m., whatever). If you are thirsty, your (as the parent) normal response should be a drink of water.
(7) Be willing to radically modify the way you live your life (commute, where the kids go to school, where your leisure dollar goes, etc.) in support of physical activity for _everyone_ in the family.
This is considerably more complex than my previous rules (Eat what you crave. Eat more than one thing. Try new foods periodically (where new means new-real, not yet-another-processed-x). Stop eating when you are full.), but not incompatible.
One last remark about something that came up again and again in the course of _Teenage Waistland_. I don't _care_ if people in a family can eat 20 pounds of chocolate for breakfast and lose a pound (I would lose more than that; I'd start throwing up after the first 8 ounces and not be able to eat any more), or eat Big Macs three meals a day and not gain weight. These are rotten food choices for _anyone_, and confuse weight with health. The idea that it makes sense for the slender folk in the family to have all this crap around the house in a secret stash when someone else is desperately trying to make more reasonable choices makes me _really_ question who in that family has the food addiction.