Ah, the battle over food, the one thing a child can control is what and when they eat, even a newborn infant knows when they're hungry and when they are not, and they have definite likes and dislikes.
Out of three children, only one turned out to imitate my eating habits, which admittadly, are not great. The two eldest will eat anything that won't eat them first, and are always open to trying new foods, my youngest, well different story.
Both he and I have real food adversions. If the food looks funny, smells strange or looks the least bit overdone, slimy etc. It dosen't go past our teeth, he's 15 now, and eats like a normal teenage boy, try filling him, but he and I eat the same things, mostly fruits and vegetables, and a little bit of meat, and yes junk does get in there, but only in moderation I control what comes in the house.
I think we as parents have to look at our own eating habits before we can judge our children as picky. Are you open to new food ? If you are served something that looks strange do you make faces at it ? Sometimes we give off these signals without even realizing it. Do you eat breakfast, and if you do is it balanced, or is it a cup of coffee and a piece of toast ? Do you eat dinner as a family, giving children choices what I mean is not becoming a short order cook, but allow them to help plan the family meal, "we can have hot dogs tonight, but we have to have carrots with it, would you like them cooked or raw ?" Even young children like to have some choices, and like I said, food is one thing they can control for themselves.
Sitting down as a family, turning off the TV, letting the answering machine pick up the phone, telling friends and family that dinnertime is for the family, and you will not be taking calls or visitors during that hour, leave the cell phone in the other room, and really re connect, Unless someone is working, the family meal is almost sacred at my house and it has helped, my son and I get distracted with the conversation, and don't realize what we are eating. Not bringing up problems through the day, but keep the conversation light, and make clean up a family affair as well, even a two year old can learn to put dishes in the sink or dishwasher with supervision.
As for young children worrying about weight, again, how do you respond to overweight children and adults ? They take their cues from us, part of being their most IMPORTANT role models not models, actors, singers whatever, it is us and we can't expect them to have good eating habits if we don't.
Routine and cosistency were my best friends when the kids were small, and they learned to listen to their bodies, they were NEVER forced to eat, but they were made to sit with the family for meals, and "if you can't eat your meal (too full, sore tummy I've heard them all) then you can't eat cookies or desert " then stick to it, if you are worried about them starving, offer a piece of fruit or veggie, but desert and cookies etc. are treats and not the mainstay of a healthy diet.
My trick when my son got about six, he would say "I want a sandwich, " we would say fine, "go make it, Mom only makes one meal for everyone. " It was amazing, he wasn't getting his way, and he ate what was on his plate.