Overhaul Your Family's Eating Habits

Start the day smart. "Eating lots of sugar in the morning sets you up for an energy crash later in the day," Katz says. He urged Brigid to stick to foods that would keep her family feeling full until lunchtime. Keep it simple, he advised. In winter offer a hot breakfast: scrambled eggs or oatmeal sprinkled with almonds. In summer switch to a low-sugar, high-fiber cold cereal with nonfat milk, plus a piece of fresh fruit.

Protect against temptation. Katz didn't want Brigid coming home so hungry that she dialed for pizza delivery instead of cooking dinner. "A healthy afternoon snack—fresh fruit, homemade trail mix, nonfat yogurt topped with nuts—will help steel your resolve to eat well by keeping you satiated," he told her. Snacks don't always have to be low in calories, but they should be nutritious and filling.

Make lunch simple. Preparing her own lunch will give Brigid more control over her nutrition. To avoid the morning crunch—and the urge to grab a frozen entrée on the way out the door—Katz advised her to get in the habit of prepping lunch for herself and the kids the night before. She can incorporate leftovers from dinner (for example, grilled chicken can be cut up and added to a salad) or toss a few ingredients into a slow cooker at night and wake up to a simmering soup or stew.

Build a dinner repertoire. "Brigid has a fully appointed kitchen, but what she was missing was a plan," says Katz. "She wasn't comfortable with her cooking skills, and the idea of making dinner from scratch every night was overwhelming." But you don't need to be Julia Child—all you need is a dozen go-to dishes that your family likes. Start by learning one or two new recipes a week. ( See Katz's recipe for lemon salmon with garlic spinach .)

Katz suggested that Brigid set aside time on weekends for grocery shopping and cooking. She now makes big meals on Saturday and Sunday nights and freezes the extra portions for later in the week. "If you do that, you're already eating home-cooked meals four nights out of seven," says Katz.

As Brigid becomes more comfortable in the kitchen, she can get the kids involved in food preparation. "It may take longer to get dinner on the table, but it gives your kids ownership over their food," says Katz. "They've actually helped choose and prepare it."

For nights when the family wants to eat out, Brigid identified a local restaurant that offers more nutritious options than fast food. She also occasionally relies on premade food from the grocery store. "If you buy a roasted chicken, then all you need to grab is salad greens and a loaf of whole grain bread," says Katz. "It's just as easy as takeout but a lot healthier and a lot less expensive."

Read this before going food shopping: 4 rules for navigating nutrition labels