Putting together a decent lunch for school or work can leave many of us a little exasperated. Maybe you're not fond of leftovers in your lunch bag. Perhaps you've taken one trip too many to the food court.

Could be that most of us are too pressed for time to put together a fresh lunch. So we resort to the quick and easy — which isn't necessarily a bad thing.

There's a lot more choice in pre-packaged foods, and if you pay attention to the nutrition labels, you can find nutritious options.

But there is a cost. You may be giving up fresh ingredients for more calories than you bargained for, higher sodium content and a list of ingredients that leaves you scratching your head.

We're looking at a number of popular products that wind up in lunch bags across the country and examining what's in them. We're neither endorsing nor condemning these products; we're just explaining what the ingredients are and how they're dealt with by Canada's product labelling regulations.

What's in it: Chef Boyardee Mac & Cheese

This is a microwaveable macaroni and cheese product that comes in 212- and 403-gram servings. It contains the following ingredients:

Macaroni (durum semolina, egg whites): When an ingredient is made from other ingredients, they are included in the list of ingredients in parentheses. Under Canada's Food and Drug Regulations, you cannot sell macaroni, spaghetti or noodles as egg macaroni, egg spaghetti or egg noodles unless they contain, "on the dry basis, not less than four per cent egg-yolk solids derived from whole egg, dried egg, frozen egg or frozen egg yolk."

Durum semolina is a type of wheat used in making pasta. It contains the most gluten of any type of wheat.

Processed cheese food: The best known product to fall under this category is probably those cheese slices that come wrapped in plastic. The Food and Drug Regulations define processed cheese food as the product made by "comminuting and mixing one or more varieties of cheese, other than cream cheese, cottage cheese or whey cheese, into a homogeneous mass with the aid of heat." If you're not familiar with "comminuting," it means "reducing to powder, pulverizing."

Processed cheese food also contains:

• Added milk or milk products.
• Not less than 51 per cent cheese.
• Not more than 46 per cent moisture.
• Not less than 23 per cent milk fat.

It may also contain:

• Added water to adjust the moisture content.
• Added milk fat.
• Salt, vinegar and sweetening agents.

Processed cheese food can also contain colouring, emulsifying, gelling, stabilizing and thickening agents and preservatives.

Cheddar cheese: You can call a cheese cheddar if it's made by "coagulating milk, milk products or a combination of those things with the aid of bacteria to form a curd and subjecting the curd to the cheddar process or any process other than the cheddar process that produces a cheese having the same physical, chemical and organoleptic properties as those of cheese produced by the cheddar process."

It must also have a casein content that is derived from milk or from ultrafiltered milk, partly skimmed milk, ultrafiltered partly skimmed milk, skim milk, ultrafiltered skim milk or cream, rather than from other milk products, and that is at least 83 per cent of the total protein content of the cheese. To be called "cheddar," the cheese must also contain:

• Not more than 39 per cent moisture.
• Not less than 31 per cent milk fat.

It may contain:

• Salt.
• Flavouring preparations other than cheese flavouring.
• Bacterial cultures to aid further ripening.

To give it that orange colour in popular brands, cheddar may also contain certain colouring agents "in an amount consistent with good manufacturing practice."

Glucose-fructose and/or sugar: It's called glucose-fructose in Canada but it goes by the name of high fructose corn syrup south of the border. Basically it's an inexpensive sweetener. Under Canada's labelling regulations, if it's called glucose-fructose, the fructose fraction may not exceed 60 per cent of the sweetener on a dry basis.

Glucose-fructose is made from corn. After it's milled, the resulting starch is processed into syrup. By adding enzymes, the syrup is converted into fructose. Glucose syrup is then added to the mix to make "high-fructose corn syrup." The most common form of the syrup contains 45 per cent glucose and 55 per cent fructose.

By including "glucose-fructose and/or sugar" on the label, the manufacturer can use either ingredient or a combination of the two.

Powdered sweet cream: The term "sweet cream" is sometimes used to describe cream that is skimmed from milk, to distinguish it from cream that is skimmed from whey, a byproduct of cheese making. "Whey cream" is saltier and tangier than "sweet cream."

Sea salts: Canadian rules permit the use of the term "sea salts," which are a mixture of sodium chloride and other mineral salts. Sea salts must be made from sea water. They cannot be produced from mines. Sea salt (singular) is just sodium chloride and does not contain other mineral salts. Sea salts and sea salt do not have to be iodized like table salt.

Margarine: The Food and Drugs Regulations decree that margarine "shall be a plastic or fluid emulsion of water in fats, oil, or fats and oil that are not derived from milk and may have been subjected to hydrogenation."

It must contain not less than 80 per cent fat, oil, or fat and oil calculated as fat, and at least 3,300 International Units of vitamin A, and 530 International Units of vitamin D, per 100 grams. Margarine may also contain skim milk powder, buttermilk powder, liquid buttermilk, whey solids or modified whey solids.

Chef Boyardee Mac & Cheese also lists soy lecithin in parentheses after margarine in the ingredient list. It's used to help keep margarine solid. It's also used in coating for chocolates and to give consistent textures to creams and dressings.

Modified corn starch: Pure corn starch is extracted from the endosperm of corn kernels. It can be modified by physically, enzymatically or chemically treating pure starch to change its properties. In the case of Chef Boyardee Mac & Cheese, the starch is modified so the cheese sauce will thicken without going lumpy when boiling water is added.

Milk ingredient: The term milk ingredients is an umbrella term that can be used to refer to a range of items. According to the Canadian Food and Drug Regulations, the term can be used to refer to "any of the following in liquid, concentrated, dry, frozen or reconstituted form, namely, butter, buttermilk, butter oil, milk fat, cream, milk, partly skimmed milk, skim milk and any other component of milk the chemical composition of which has not been altered and that exists in the food in the same chemical state in which it is found in milk."

Natural cheese flavour/Natural butter cheddar flavour: Both ingredients are listed on the label of this product. Under the Canadian Food and Drug Regulations, flavours may contain a sweetening agent, food colour, preservatives, thaumatin (a sweet flavour modifier) and an emulsifying agent. Liquids including water, benzyl alcohol and edible vegetable oil may also be added to the mix.

Also, the Canadian Food Inspection Agency notes that substances that "impart flavours which have been derived from a plant or animal source may be claimed to be 'natural.' " While the ingredient can be described as "natural," the food itself cannot, since it contains an added component.

Colour (contains tartrazine): Tartrazine, also referred to as Yellow #5 or E102, is a yellow dye commonly used in foods and beverages.

Health Canada in February 2010 said it intends to change regulations governing food colouring labelling. Under the current regulations, food colours must be listed in ingredients list. Manufacturers have the option of listing the colours using their specific common name or under the umbrella label "colours" — with the exception of tocino and longaniza sausages, where the colours must be identified by name.

As of July 20, 2010, the European Union said manufacturers that included tartrazine in their food items must include the label "may have an adverse effect on activity and attention in children."

The U.K. Food Standards Agency has called on manufacturers to voluntarily avoid using a series of colours, including tartrazine in food and beverage products, suggesting that the dye was linked with hyperactivity in children.

Health Canada noted, however, that susceptibility to adverse health effects varies from person to person and called for clear and specific labelling of food colours in place of a voluntary ban.

Finally, the Chef Boyardee product label says the macaroni and cheese contains wheat, soy, milk and egg. That's basically a warning for people who have allergies to those products. Even when not listed among the main ingredients, they may appear in trace amounts.