When Alisa Smith and J.B. MacKinnon set their mugs down on a table at Café Calabria, the first thing they do is read the label attached to the tea bag. It doesn't show what they would like to see–namely, where that tea originated. Food origins have been on their minds ever since the evening when, faced with guests and no provisions apart from an elderly cabbage, they hunted and gathered together a meal out of what they found close to their cabin in northern B.C.: a Dolly Varden trout, wild mushrooms, potatoes and garlic from the garden, dandelion leaves, apples, sour cherries, and rose hips. The feast was so delicious that once they learned how far most of our food has to travel, they embarked on a year of eating locally, describing the process first in on-line columns and now in The 100-Mile Diet: A Year of Local Eating (Random House Canada, $32.95). Engagingly written with admirable honesty (the experience wasn't all juice-dripping peaches), Smith and MacKinnon alternate authorship as they take readers along on the month-by-month journey.

At times, their self-imposed challenge was difficult enough in balmy British Columbia, but what about the frigid rest of Canada? Smith tells of a winter farmers market she visited just outside Saskatoon, which sold local meat and flour, pointing out that "flour was the biggest gap in our diet" during the project, which began in March 2005. Because they had yet to climb aboard the growing-preserving-consuming cycle that kept our ancestors fed, they ate a lot of potatoes.

Still, the facts are persuasive enough to turn book readers into label readers, and that's one of the desired effects, they say. Other good things are also starting to happen. As MacKinnon says, urban farmers in Victoria can now keep a certain number of chickens in the back yard and local farmers are realizing there's a market for flour. But is it merely a passing trend? "It's deeper than that," he says. "It's going to transform the food system over the next 10 to 15 years." Adds Smith: "In 10 years, we'll see more of it in restaurants, not just fancy ones."

The couple keeps careful tabs on what's happening elsewhere. MacKinnon describes "a UK move to push local supermarkets to provide space for local farmers". He would like to see grocery stores showcasing local produce as they do organics, and a farmers market in each neighbourhood. Feedback from www.100milediet.org/ ("the public meeting space of the not-for-profit 100-Mile Diet Society") shows the idea growing like Jack's organic beanstalk. A Vancouverite is planning a 100-Mile Diet bike trip around the Americas; an Ottawa restaurant organized a 100-kilometre breakfast; folks in Michigan, Missouri, and Minneapolis have become proud "locavores". This summer, Smith and MacKinnon plan to grow green beans and cherry tomatoes in pots. Foraging gets them chickweed and blackberries. They use local honey, not sugar, because the sugar company mixes cane with Alberta beet.

Following their approach keeps minds and palates awake. Food, they point out, comes from increasingly further away with vague labelling that might describe asparagus grown in "California or Peru". When you buy local, "You really enjoy it for that season and then you forget about it," says MacKinnon, praising the flavour of fresh food. "It's the opposite of deprivation. It's a feeling of abundance." (The U.S. edition of their book is titled Plenty.) Says Smith: "It's all home cooking. That's always healthier than processed foods. People who eat lots of fast foods in a week would notice a huge difference" if they switched.

Two nights ago, the couple sat down to seared tuna with wasabi and nori, both from the winter farmers market, and local carrots; a friend brought beans, which, they admit, were probably well travelled. "We're not eating 100 percent, probably about 85 percent local," says MacKinnon. "I can't see us dipping below that."