Absolutely. About the only companies I would want to steal from are shitbags like Electronic Arts (piracy) or Walmart (fuck "self-checkout") or (as stated) Loblaws. Any company of over 10k employees (well, as an estimate, at least) without a Union for their labor and service employees deserves a little shrinkage as punishment.

Mom and Pop stores are already struggling to make a living. If you need food that badly though (such as if you are homeless) then I recommend asking a mom and pop store if they have left over baked goods or newly-expired milk that doesn't smell funky. They're in the same boots, even if theirs is a comfier fit, and they will usually say yes to someone asking to eat goods that can no longer be sold.

That, and if you do decide to ask a larger grocer they're more likely to say no in some places, but that's because corporate scumbags want to force people to have to buy food to live. Hence why.a supermarket or big box store is more acceptable to snatch food from. Do it at the end of the day just before closing, the employees of a store like that and the cops (at least here in Canada) are more likely to be understanding if you get caught. Worst case scenario, you spend time awaiting a trial that will likely be thrown out due to how petty it will look to a judge to charge someone for stealing almost-expired bread (and if he/she doesn't, a reliable public defense attorney will point it out and reduce/negate your sentence).

Ask first is always the key, and only if you really are on the street or your paycheck is gone and your fridge empty and the month not close to being over. If they say no, ask elsewhere. If everyone says no (which has happened in places with arrogant assholes in City Hall deciding to discriminate against homeless people) then yeah, fuck the rules, take what you need to live.

I wonder if stealing food while literally malnourished could count as self-defense in a court of law?