Here's something you might not have realized about your local grocery store: These markets are super places to teach your children about good nutrition. "It's a learning lab if a parent wants to take advantage of it and engage the child," says Barb Mayfield, a registered dietitian who specializes in early childhood nutrition. Grocery-store lessons are one of the most important things you can pass on to your kids, especially with childhood obesity and the health problems associated with it on the rapid rise. These supermarket activities help set good eating habits early.

Kids learn best when they're a part of the process and can make choices for themselves. When the child helps the parent, they have a vested interest when the food reaches the table, so they'll actually eat what you put in front of them. One idea: Give them the choice of which vegetables to buy for the next night's supper.

It teaches children the importance of planning and not buying on impulse. It also gives parents a handy excuse when kids are clamoring for the chocolate bars in the checkout lines. "Sorry," you can say. "We have to stick to the list."

Ask older children to find cereal or breakfast bars with the least amount of sugar. "Challenge your kids to find out who's the real 100-percent juice and who's the imposter," says Connie Evers, a registered dietitian and author of How to Teach Nutrition to Kids. "It's cool with kids because they're so curious. You literally see the light bulb go off." Or have them compare the fat content of snack crackers or fiber in whole grain versus white bagels. Reading labels is enlightening, and many kids don't do it until adulthood. By then, food-purchasing patterns have largely been formed.

Yes, this is an exception to the Take-a-List rule, but a worthwhile one. Each trip, ask your child to pick out one new food they haven't eaten before. Kids are so picky when it comes to food, this will make them branch out and open their taste buds to something new.

Don't label nutritionally weak foods as "bad." Negative labels create an unwarranted mystique around things, even going as far as to make kids want the off-limits goodies more. Instead of saying, "You can't have this or you can't have that," ask, "How are we going to get more fruits?" Then recruit their help in coming up with creative ways to get a minimum of five servings of fruits and vegetables a day into their diets.