If you've ever found a soggy sandwich tucked away in your child's backpack, it's safe to assume they didn't find it all that appetizing.

But why not? Perhaps you're the long-suffering parent of a picky eater. Or maybe your child is on a hunger strike against your bland bologna on rye.

Every child has its preferences — and perhaps special dietary needs — and there are always school rules to follow, so packing the perfect lunch is a subjective affair. Still, you can come close with a nutritious, allergen-free, smartly packaged and even educational meal.

Here are some pointers.

What not to buy

Before you put the same old ingredients in your shopping cart, it may be worth thinking about the items that should be left on the shelf.

Increasingly, parents are being asked to put safety first, as about six per cent of Canadian children are affected by food allergies.

Health Canada offers many resources for those who want to learn about common allergens, and notes that the foods most likely to trigger severe reactions are peanuts, tree nuts, sesame seeds, soy, seafood, wheat, eggs, milk, mustard and sulphites.

Parents should always check whether their child's school bans these or other foods. The kids who are allergic to them could suffer everything from skin irritation to life-threatening reactions – and so anything that may trigger those reactions has no place in the perfect lunch.

From a nutritional standpoint, there are also a few items that should seldom or never go into children’s lunch boxes. They are often the brightly packaged but nutritionally deficient products that seem marketed directly to pint-sized shoppers.

Registered dietitian Beata Blajer, who conducts nutrition workshops at schools and daycares, cautions against juice boxes, soft drinks, candy, sugary cookies, salty snacks and white flour-based breads.

"They're convenient and kids like them, so parents just give in," said Blajer, who works at Southlake Regional Health Centre in Newmarket, Ont., and also runs a private practice.

So, what should we consider for the perfect lunchbox?

Main course

There are several variables that go into planning the centerpiece of your child's meal. Nutrition is key, but so too are portion size, food groups and variety.

A kid-friendly adaptation of Canada's Food Guide provides a few more specific ideas.

• Eric, seven, gets a sandwich made with a whole wheat pita. It contains 30 grams of chicken, shredded lettuce, tomato and a little bit of mayonnaise.
• David, 10, gets a hamburger. It contains a 90 grams of hamburger on a whole wheat hamburger bun, lettuce and tomato and fruit salad on the side.
• Isabelle, 12, gets a homemade whole wheat pita pizza with tomato sauce, mozzarella cheese, diced chicken, mushrooms and peppers as well as a large kiwi on the side.

Of course, busy parents don't always have time to make home-cooked favourites in the morning, so dietitians suggest meal preparation is easier when you plan ahead.

The 'perfect' main course: Quinoa soup. Fibre and protein-rich Quinoa is considered to be one of the most nutritional foods in the world. As the base of a soup, it can be paired with hearty vegetables – like potatoes, carrots and corn – and packaged in a portion that's right for your kid. It's also a less common lunch, providing your child a chance to break from routine and learn about a new food. (iStock Photo)

"I make enough dinner so it will last us for lunch the next day," said Blajer, adding that one of her staples is whole grain pasta with chicken and real vegetables in the tomato sauce.

Paying attention to how much your child eats at the dinner table is also a good way of tailoring their portion size — especially because younger children often have small appetites.

It is also an opportune time to try out new meal ideas, as kids tend to reject unfamiliar food the first time they see it. Health Canada advises parents to be persistent.

"The more often children are exposed to new foods, the more likely they are to accept them," it notes in its Healthy Eating Guide for Children.

Also, remember to read labels, because many foods contain trace amounts of the allergens that can cause severe reactions. Avoid labels with warnings that say “may contain.”

If your school's allergen policy restricts popular snack ingredients like peanut butter, Canada’s Food Guide recommends hummus or apple butter instead.

Blajer added that sunflower and hempseed butter could fill in for the often-banned peanut butter, but it's always important to double-check the safety of substitutes with the school in question.

Drinks

Parents should avoid sweetened, low-nutrient beverages, like those with less than 100 per cent fruit juice, as well as lemonades, regular soft drinks, and sweetened coffees or teas.

The perfect drink: Water. Put it in a sturdy reusable bottle full of cold, refreshing tap water. It can be filtered at home and refilled at the school fountain. You can't go wrong with the original thirst quencher. (iStock photo)

Energy drinks and beverages with caffeine or caffeine-like ingredients — which the Canadian Medical Association Journal has even referred to as "drugs delivered as tasty syrups" — should also stay out of the lunchbox.

Instead of juice boxes and pop cans, Blajer recommends nixing fruit juice, or "sugar water," in favour of a smoothie made with real fruit.

She also suggests sending your kid to school with a water bottle in tow.

If that seems far too simple, consider that in places like Nantes, France, school lunch programs only serve water. Since 2005, vending machines with soft drinks have been banned in French schools.

Some of the drinks recommended by Health Canada include two per cent milk and low-sodium vegetable juice.

Snacks

Time-crunched parents who would like to compare the sugar, salt and fat content in some of the most popular snack foods can check out our interactive chart.

The perfect snack: Apple slices and yogurt. Kids are less likely to bring home bruised fruit if they're sliced ahead of time. Choose a variety of apple that your child enjoys, and send it along with a tightly-sealed container of Greek-style yogurt -- perhaps with a splash of vanilla or a bit of honey or brown sugar -- in which to dip their fruit. (iStock Photo)

The database features 170 foods that can be filtered and sorted according to your specifications, including one large banana, an 85-gram serving of baby carrots and several brand-specific items.

Some snacks recommended by Health Canada include:

• A fruit cup or carrot sticks with dip for seven-year-old Eric
• A homemade muffin (with non-hydrogenated margarine) or an English muffin with cheese or 10 grapes for 10-year-old David
• An apple or 15 cherries or two cups of popcorn (with melted non-hydrogenated margarine) for 12-year-old Isabelle

If your kid loves cheesy chips, perhaps try cheese slices and whole-grain crackers. If chocolate and icing covered snack bars are a staple, maybe sub in a custom munchie mix instead.

"Kids can make up their own munchie mix. The kids really enjoy it because they can tailor it to themselves and they feel like they're having fun," said registered dietitian Shannon Crocker.

Crocker suggests ingredients like whole-wheat cereal squares, dried fruit, popcorn and seeds that aren't an allergy concern at your child's school.

Container

Environmentally conscious parents, or those that have litterless lunch programs at their schools, may give extra thought to the reusable lunch boxes they send to school.

The perfect lunchbox: sturdy, clean reusable container(s). Many containers are now designed with multiple functions in mind. A thermos to keep your Quinoa soup hot may also have a compartment for your apple slices, for instance. Have a few options at home but make sure they're thoroughly washed when returned. (iStock Photo)

A recent study by the Lysol and the Global Hygiene Council suggests parents should disinfect containers each day, rinse them with warm water and then refrigerate them after preparation.

"A lunch box is supposed to keep kids' food safe, but in some cases, the lunch box can do the exact opposite," said Dr. Donald Low, the chief microbiologist at Toronto's Mount Sinai Hospital.

"If lunch boxes are not cleaned daily, small spills and crumbs can lead to bacteria growth and spread to ready-to-eat food, potentially causing children to get food poisoning or sick with diarrhea."

Researchers also recommend teaching kids thorough hand-washing techniques and how to wipe down their table before lunch.

Food for thought

Another thing you may want to consider for your child is a bit of food for thought, as the perfect meal in your household may contain the seeds of identity and family values.

Perhaps you are teaching your kids about local, organic or fairly traded foods.

Maybe you think it's important for your child to understand their meal in a global context — like whether what they are eating has roots in the culinary traditions of another country.

Toronto writer Andrea Curtis' recently published book What's for Lunch is all about how and what schoolchildren eat around the world.

She lists a typical meal for a Canadian child as a cheese sandwich, a package of mini-cookies, a small bag of baby carrots, a fruity drink and a small yogurt.

Although the writer says this meal is representative of what many Canadian children eat, she does not think it is necessarily an optimal meal.

"Canada is one of the few developed nations in the world that doesn’t offer a national nutrition program for school-age children," she notes, adding that parents have a lot on their plate when planning meals.