But many people simply don't know how to tweak, much less overhaul, their food choices. Take these two examples, not uncommon in the landscape of poor diets: Anita Fuentes, a mother of three in Los Angeles, had found that too many dinner entrees were fried, even though her kids loved them. Rafael Navarro and Duncan MacLeod, an overbooked working couple, had gotten into the eating-out cycle. That's where we thought we could help. We asked Emily Ventura, a nutrition expert and research associate at the University of Southern California's Childhood Obesity Research Center at the Keck School of Medicine, to visit the families' homes with us. An advocate of local farmers markets, Ventura firmly believes that people who don't eat fruits and vegetables can be swayed once they realize how flavorful such foods can be. She avoids overly processed foods, like chips, cookies and crackers, that have little nutritional value, pushing quality carbohydrates found in good produce and whole grains instead. She peered into the families' cupboards and refrigerators, analyzed their eating habits and critiqued their meals. Then she told them how to do better. Not only did she offer suggestions for more healthful meals, snacks and smarter eating habits, she also revamped their favorite recipes. She got a warm reception and enthusiastic responses. But we'll see -- we'll revisit these homes in a month to see what changes, if any, have been made, and if diets have improved. 