More than $31 billion worth of food is wasted every year in Canada and when energy, water and other resource costs are factored in the true cost could be up to three times that much, a new report suggests.

Consulting firm Value Chain Management International published a report this week that tabulates the total monetary cost of the millions of kilograms of food that goes to waste every year in Canadian homes, restaurants and grocery stores.

That's a 15 per cent increase from the report's findings four years ago, when the group found the cost was $27 billion in 2010. It's also two per cent of Canada's total GDP, and larger than the total economic output of the poorest 29 countries on the planet.

The report acknowledges that the total doesn't include what's being wasted at federal institutions like prisons, jails, hospitals and schools because there isn't reliable data on that. If those numbers are included, along with the true cost of things like energy, water, land, labour, capital investment, infrastructure, machinery and transport, the true cost of wasted food is actually closer to $100 billion a year.

Even among the areas tracked, food is wasted in many ways every day. Among them:

Individuals waste some $14.6 billion worth of food every year, about 47 per cent of the total. This mainly consists of food items that Canadians buy with the intention of using in their homes, but never do, so it ends up eventually in a landfill or composted.

Food manufacturing and processing is responsible for as much as one-fifth of the food wasted across the country.

Ten per cent of food waste happens on a farm, before even entering the broader system.

Retailers waste another 10 per cent

Restaurants and hotels waste a further nine per cent

The rest is wasted at processing facilities such as food terminals, or during transportation

The report notes that food waste in the travel sector is especially egregious — up to five kilograms per person, per day, according to some estimates. Even using more conservative estimates, the paper says one could feed 200,000 inhabitants of poorer countries for a year with nothing more than the food that gets wasted on European airlines every year.

On international flights, regulations require any excess food be thrown out after a flight — regardless of whether it was used. And cruise liners are the worst culprit, generating the highest per capita food waste.

Waste like that costs everyone, not just the person who bought the food and the person who made it. The report estimates that what it calls "avoidable" food waste can increase the cost of food by 10 per cent or more. The costs for businesses can be even higher, but for some reason, many are reluctant to take steps to fix the problem because of a perception it's not worth the effort.

"Consumers are busy picking off deals, while retailers and suppliers are busy picking off each other," one unnamed food industry expert quoted in the report said. "This produces enormous amounts of food waste and is unsustainable."