Kristy Noble's home is a tale of two diets.

Outside, cherry tomatoes grow abundantly in the well-groomed back yard; fruit trees yield apples; and a flourishing herb garden produces basil, sage and mint to spare. But inside, the freezer is stocked with 5-quart containers of ice cream; the cupboard holds tubs of cookies; and oatmeal, whole grains and skim milk share space with sugary cereals and fatty hamburger patties.

Noble is a substitute teacher and tutors students at home, so her daily schedule is rarely regular. The lack of routine means she might grab a quick breakfast, then not eat until evening. Time-consuming recipes are out of the question.

Scott and Robert are busy with soccer, studying and school activities. They often prepare breakfast on their own but sometimes skip lunch and arrive home hungry. Very hungry. Their appetites are healthy, to say the least - a snack can be an entire quart of yogurt or a couple of peanut butter and jelly sandwiches.

Registered dietitian Lisa Gibson is impressed with the garden and the fact that Noble cans her own fruits and vegetables but is less awed by the family's basic food supply. Starting in the garage, Gibson finds huge jars of Skippy peanut butter, cans of refried beans and large bags of cereal. She approves of peanut butter on principle - it's a terrific source of protein and good fats - but she prefers more natural versions, without vegetable oil stabilizers and added sugar. The refried beans, low in fat and packed with nutrients, get high marks. Some cereals pass muster, such as the Raisin Bran, but the crispy rice and cinnamon swirls don't.

Gibson stops in her tracks at a 6-pound, 9-ounce can of pears; Noble says the boys might devour the entire contents in two days.

In the kitchen, Noble prepares a lentil stew for dinner while her sons do homework. Gibson continues searching the cupboards and refrigerator. She finds good-for-you oatmeal and a jar of whole grains, plus cans of beans and tomatoes - even tomatoes that Noble has canned herself. She also finds a stash of nuts and raisins - Noble's relatively healthy snacks when she doesn't have time for a formal meal.

The refrigerator has bright spots: several gallons of skim milk, a whole chicken, grapes, carrots and green beans. But a block of mild cheddar cheese, which does provide protein, is high in saturated fat and cholesterol.

The quarts of yogurt are a good source of protein and calcium, but Gibson points out that if one serving is 250 calories, eating a whole tub of the sweetened, low-fat kind would amount to 1,000 calories, 11 grams of fat and about 180 grams of sugar.

The freezer holds several bags of frozen vegetables and blueberries but also packages of pre-made hamburger patties (330 calories and 23 grams of fat each) along with three 5-quart containers of ice cream, which the family eats almost daily. Although it's not premium ice cream, which has much more fat (a half-cup serving of the less expensive kind contains 140 calories and 7 grams of fat), it's usually eaten in larger quantities. Tubs of Trader Joe's cookies sit in the cupboard above the refrigerator. Then there's Noble's stash of dark chocolate chips.

Overall, Gibson likes the fact that the family eats at home every night, grows some of its own vegetables, doesn't indulge in fast food and bans chips and soda from the house. But she worries that the mother's and sons' diets lack essential vitamins and nutrients.

Noble typically eats little all day - perhaps a small bowl of cereal in the morning, followed by a few handfuls of nuts and maybe an apple, then dinner, which could be a tortilla with roasted chicken or an egg burrito. On one recent day, she consumed only 1,031 calories but didn't eat her first meal until 6:30 p.m.

Scott and Robert get protein from good sources (skim milk and yogurt) and not-so-good sources (hamburgers). Although they're young and slim, they need to eat more balanced meals with many more fruits and vegetables and lean proteins.

Says Gibson to Noble: "I think you have good intentions, but you can't quite get there."

Among Gibson's suggestions for Noble:

  • Buy an inexpensive crock pot for simple main-dish recipes that include vegetables, such as chilis and stews. A dish prepared in the morning will be ready by evening, and most vegetables, which can be quickly rough-chopped, retain their nutrients and fiber after cooking.

  • Add nutrition to pasta, which the boys usually eat with only olive oil and cheese, via tomato sauce and turkey meatballs.

  • Mix fiber-rich plain cereals, which the boys don't like, with the sweetened cereals they prefer.

  • Replace cheddar cheese with feta, which is lower in fat and usually consumed in smaller quantities because of its strong flavor.

  • Cook entrees on weekends and freeze them, providing meals throughout the week.

  • Overhaul the snacks. Although Noble usually doesn't prepare salads because the produce tends to spoil quickly, Gibson recommends combining dark, leafy greens, beans, tuna, canned salmon or chicken as an afternoon snack - and topping it with an olive oil-based dressing that provides good fats. If the boys like it, chances are there won't be many leftovers.

  • Eat more regularly during the day, focusing on lean protein, which may make Noble specifically less compelled to pounce on the sweets.