If you were to open your fridge right now, how much of the food in there would be destined for the bin?

Turns out, you're not the only one guilty of buying too much, only to throw it away later.

Forty per cent of food produced in North America is wasted.

A lot of of good gets thrown out in the field during production as food processing companies toss fruits and vegetables that aren't the right shape or size for marketing or packaging. But half of the food waste occurring in North America is happening in our own kitchens.

Now a new cookbook aims to help people reduce the amount of food they throw away.

"It's not only a serious ethical issue of throwing away that much food when people are going hungry in the world, but it's become a huge environmental issue," says Cinda Chavich, author of "The Waste Not Want Not Cook Book: Save Food, Save Money and Save the Planet."

If food waste was a country, she says, it would be the third largest CO2 producer on the planet, after the U.S. and China, making food waste a serious global warming issue.

Chavich spoke with North by Northwest host Sheryl MacKay about the top reasons why food is being thrown out and what we can do stop it.

Tips to reduce food waste

Canadians are wasting about 6 kg of food a month, she says.

"It's like every time you go to the supermarket buying three bags of groceries and dropping one in the parking lot before you get to your car," said Chavich.​

Here are some of the reasons why.

1. Buying too much

North Americans generally don't have to spend too much of their income on food, so they overbuy.

In the 1960s, Canadians were spending about 18 per cent of their household income on food. In 2010, they were spending about 10 per cent.

In comparison, people in France spend about 14 per cent of their household income on food, which Chavich argues, forces them to value their food a lot more.

If we understood the true cost of what we're wasting, she thinks things would be different. In Canada, It's estimated that $31 billion of food is wasted every year, meaning individuals are throwing away close to $1,500 a year or more from wasted food.

2. Best before date panic

"Best before does not mean poison after," Chavich said.

People see a best before date and panic, needlessly throwing out food that might still be good, says Chavich. Best before dates are not required by law, she says, but are something the processing industry came up with to make sure their products are always being circulated.

Things do get stale eventually, she says, but use your nose. When you open a package and take a sniff you'll know whether it's still edible or not.

3. Storage confusion

Fruits and vegetables often end up going bad sooner than they should because they're not being stored properly, says Chavich. Tomatoes, for example, should never be put in the fridge unless they're already extremely ripe.

Apples give off ethylene gas as they're ripening and so should never be stored with bananas or the bananas will go bad quickly. Leafy greens like to stay moist but not soggy. Wrapping them in a paper towel and putting them in a plastic bag will keep them fresh.

4. Shop local

Knowing where food comes from will make you care more about it, says Chavich. People complain its more expensive but if you're going to a big box store and throwing out half of what you buy, you're not saving any money, she says. If you have something local and know who grew it and have that attachment to it, you're more likely to value it.

5. Keep track of what's in your fridge

Open up your fridge and see what's in there and what you can make before you order a pizza or get take out, says Chavich. She puts a clear bin in the middle of her fridge and will regularly fill it with food that's starting to go bad so she knows what she needs to be using first. If you can't figure out what to do with the ingredients, just try googling them and see what you come up with, she says. Be creative.

6. Weekly feasts

When you have time, cook a big piece of protein, whether salmon or chicken or beef and plan your leftovers. That way you'll have meals for the week.

To hear the full interview with Cinda Chavich listen to the audio labelled "Food waste"

For extra inspiration, here`s a recipe from Chavich's new book.

Caponata recipe

Caponata Caponata is a chunky antipasto with roots in Sicily, great to pile on slices of crusty bread or toss with hot pasta and grated Parmesan for a speedy dinner. Make lots of caponata when eggplants, peppers, and squash are available at the market in August. Store it in jars or containers, and freeze it for instant eating anytime.

Makes 6 cups.

1 eggplant (0.5kg), skin on, diced
1 zucchini or other summer squash (0.5 kg), diced
2 tsp salt
½ cup extra-virgin olive oil
1 large onion, chopped (about 2 cups)
4 large cloves garlic, minced
1 red bell pepper, seeded and chopped
1 yellow bell pepper, seeded and chopped
1 can plum tomatoes, chopped or puréed (or 2 cups chopped fresh tomatoes)
1 Tbsp brown sugar
¼ cup tomato paste
3 Tbsp balsamic vinegar
½ cup air-cured black olives, pitted and chopped
2 to 3 Tbsp chopped fresh basil or rosemary
Salt and freshly ground black pepper, to taste
Hot sauce, to taste (optional)

Put the eggplant and zucchini cubes in a colander. Toss with the salt and set in the sink to drain for half an hour. Rinse quickly and pat dry.

In a large sauté pan or Dutch oven over medium, heat the oil. Add the onion, garlic, red pepper, and yellow pepper, and sauté for five minutes. Add the eggplant and zucchini cubes and sauté for 5 to 10 minutes, until the mixture is beginning to soften. Stir in the tomatoes, cover the pan, and cook together for 10 minutes. Remove the lid and continue to simmer until the vegetables are very soft and the liquid in the pan has been reduced, about five minutes.

In a small bowl, whisk together the brown sugar, tomato paste, and balsamic vinegar. Add to the pan and stir to combine. Mix in the olives. Remove from heat and add the basil. Season with salt and pepper (and a little hot sauce if you like it spicy).

Cool to room temperature and serve. Caponata will keep for a week in a covered container in the fridge, or it may be frozen.